1
|
Englisch AS, Hofbrucker-MacKenzie SA, Izadi-Seitz M, Kessels MM, Qualmann B. Ankrd26 is a retinoic acid-responsive plasma membrane-binding and -shaping protein critical for proper cell differentiation. Cell Rep 2024; 43:113939. [PMID: 38493476 DOI: 10.1016/j.celrep.2024.113939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 01/17/2024] [Accepted: 02/23/2024] [Indexed: 03/19/2024] Open
Abstract
Morphogens are important triggers for differentiation processes. Yet, downstream effectors that organize cell shape changes in response to morphogenic cues, such as retinoic acid, largely remain elusive. Additionally, derailed plasma membrane-derived signaling often is associated with cancer. We identify Ankrd26 as a critical player in cellular differentiation and as plasma membrane-localized protein able to self-associate and form clusters at the plasma membrane in response to retinoic acid. We show that Ankrd26 uses an N-terminal amphipathic structure for membrane binding and bending. Importantly, in an acute myeloid leukemia-associated Ankrd26 mutant, this critical structure was absent, and Ankrd26's membrane association and shaping abilities were impaired. In line with this, the mutation rendered Ankrd26 inactive in both gain-of-function and loss-of-function/rescue studies addressing retinoic acid/brain-derived neurotrophic factor (BDNF)-induced neuroblastoma differentiation. Our results highlight the importance and molecular details of Ankrd26-mediated organizational platforms for cellular differentiation at the plasma membrane and how impairment of these platforms leads to cancer-associated pathomechanisms involving these Ankrd26 properties.
Collapse
Affiliation(s)
- Anna Sofie Englisch
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany
| | - Sarah Ann Hofbrucker-MacKenzie
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany
| | - Maryam Izadi-Seitz
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany
| | - Michael Manfred Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany.
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany.
| |
Collapse
|
2
|
Ji Y, Izadi-Seitz M, Landmann A, Schwintzer L, Qualmann B, Kessels MM. EHBP1 Is Critically Involved in the Dendritic Arbor Formation and Is Coupled to Factors Promoting Actin Filament Formation. J Neurosci 2024; 44:e0236232023. [PMID: 38129132 PMCID: PMC10860635 DOI: 10.1523/jneurosci.0236-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
The coordinated action of a plethora of factors is required for the organization and dynamics of membranous structures critically underlying the development and function of cells, organs, and organisms. The evolutionary acquisition of additional amino acid motifs allows for expansion and/or specification of protein functions. We identify a thus far unrecognized motif specific for chordata EHBP1 proteins and demonstrate that this motif is critically required for interaction with syndapin I, an F-BAR domain-containing, membrane-shaping protein predominantly expressed in neurons. Gain-of-function and loss-of-function studies in rat primary hippocampal neurons (of mixed sexes) unraveled that EHBP1 has an important role in neuromorphogenesis. Surprisingly, our analyses uncovered that this newly identified function of EHBP1 did not require the domain responsible for Rab GTPase binding but was strictly dependent on EHBP1's syndapin I binding interface and on the presence of syndapin I in the developing neurons. These findings were underscored by temporally and spatially remarkable overlapping dynamics of EHBP1 and syndapin I at nascent dendritic branch sites. In addition, rescue experiments demonstrated the necessity of two additional EHBP1 domains for dendritic arborization, the C2 and CH domains. Importantly, the additionally uncovered critical involvement of the actin nucleator Cobl in EHBP1 functions suggested that not only static association with F-actin via EHBP1's CH domain is important for dendritic arbor formation but also actin nucleation. Syndapin interactions organize ternary protein complexes composed of EHBP1, syndapin I, and Cobl, and our functional data show that only together these factors give rise to proper cell shape during neuronal development.
Collapse
Affiliation(s)
- Yuanyuan Ji
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Maryam Izadi-Seitz
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Annemarie Landmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Lukas Schwintzer
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| |
Collapse
|
3
|
Izadi M, Wolf D, Seemann E, Ori A, Schwintzer L, Steiniger F, Kessels MM, Qualmann B. Membrane shapers from two distinct superfamilies cooperate in the development of neuronal morphology. J Cell Biol 2023; 222:e202211032. [PMID: 37318382 PMCID: PMC10274853 DOI: 10.1083/jcb.202211032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/27/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023] Open
Abstract
Membrane-shaping proteins are driving forces behind establishment of proper cell morphology and function. Yet, their reported structural and in vitro properties are noticeably inconsistent with many physiological membrane topology requirements. We demonstrate that dendritic arborization of neurons is powered by physically coordinated shaping mechanisms elicited by members of two distinct classes of membrane shapers: the F-BAR protein syndapin I and the N-Ank superfamily protein ankycorbin. Strikingly, membrane-tubulating activities by syndapin I, which would be detrimental during dendritic branching, were suppressed by ankycorbin. Ankycorbin's integration into syndapin I-decorated membrane surfaces instead promoted curvatures and topologies reflecting those observed physiologically. In line with the functional importance of this mechanism, ankycorbin- and syndapin I-mediated functions in dendritic arborization mutually depend on each other and on a surprisingly specific interface mediating complex formation of the two membrane shapers. These striking results uncovered cooperative and interdependent functions of members of two fundamentally different membrane shaper superfamilies as a previously unknown, pivotal principle in neuronal shape development.
Collapse
Affiliation(s)
- Maryam Izadi
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| | - David Wolf
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| | - Alessandro Ori
- Leibniz Institute on Aging—Fritz Lipmann Institute, Jena, Germany
| | - Lukas Schwintzer
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| | - Frank Steiniger
- Electron Microscopy Center, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| | - Michael Manfred Kessels
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Jena, Germany
| |
Collapse
|
4
|
González A, Covarrubias-Pinto A, Bhaskara RM, Glogger M, Kuncha SK, Xavier A, Seemann E, Misra M, Hoffmann ME, Bräuning B, Balakrishnan A, Qualmann B, Dötsch V, Schulman BA, Kessels MM, Hübner CA, Heilemann M, Hummer G, Dikić I. Ubiquitination regulates ER-phagy and remodelling of endoplasmic reticulum. Nature 2023:10.1038/s41586-023-06089-2. [PMID: 37225996 DOI: 10.1038/s41586-023-06089-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 04/14/2023] [Indexed: 05/26/2023]
Abstract
The endoplasmic reticulum (ER) undergoes continuous remodelling via a selective autophagy pathway, known as ER-phagy1. ER-phagy receptors have a central role in this process2, but the regulatory mechanism remains largely unknown. Here we report that ubiquitination of the ER-phagy receptor FAM134B within its reticulon homology domain (RHD) promotes receptor clustering and binding to lipidated LC3B, thereby stimulating ER-phagy. Molecular dynamics (MD) simulations showed how ubiquitination perturbs the RHD structure in model bilayers and enhances membrane curvature induction. Ubiquitin molecules on RHDs mediate interactions between neighbouring RHDs to form dense receptor clusters that facilitate the large-scale remodelling of lipid bilayers. Membrane remodelling was reconstituted in vitro with liposomes and ubiquitinated FAM134B. Using super-resolution microscopy, we discovered FAM134B nanoclusters and microclusters in cells. Quantitative image analysis revealed a ubiquitin-mediated increase in FAM134B oligomerization and cluster size. We found that the E3 ligase AMFR, within multimeric ER-phagy receptor clusters, catalyses FAM134B ubiquitination and regulates the dynamic flux of ER-phagy. Our results show that ubiquitination enhances RHD functions via receptor clustering, facilitates ER-phagy and controls ER remodelling in response to cellular demands.
Collapse
Affiliation(s)
- Alexis González
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Adriana Covarrubias-Pinto
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ramachandra M Bhaskara
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Marius Glogger
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Santosh K Kuncha
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Audrey Xavier
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Mohit Misra
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Marina E Hoffmann
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Bastian Bräuning
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Ashwin Balakrishnan
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Frankfurt, Germany
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Christian A Hübner
- Institute of Human Genetics, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ivan Dikić
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.
- Fraunhofer Institute of Translational Medicine and Pharmacology, Frankfurt am Main, Germany.
| |
Collapse
|
5
|
Foronda H, Fu Y, Covarrubias-Pinto A, Bocker HT, González A, Seemann E, Franzka P, Bock A, Bhaskara RM, Liebmann L, Hoffmann ME, Katona I, Koch N, Weis J, Kurth I, Gleeson JG, Reggiori F, Hummer G, Kessels MM, Qualmann B, Mari M, Dikić I, Hübner CA. Heteromeric clusters of ubiquitinated ER-shaping proteins drive ER-phagy. Nature 2023:10.1038/s41586-023-06090-9. [PMID: 37225994 DOI: 10.1038/s41586-023-06090-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 04/17/2023] [Indexed: 05/26/2023]
Abstract
Membrane-shaping proteins characterized by reticulon homology domains play an important part in the dynamic remodelling of the endoplasmic reticulum (ER). An example of such a protein is FAM134B, which can bind LC3 proteins and mediate the degradation of ER sheets through selective autophagy (ER-phagy)1. Mutations in FAM134B result in a neurodegenerative disorder in humans that mainly affects sensory and autonomic neurons2. Here we report that ARL6IP1, another ER-shaping protein that contains a reticulon homology domain and is associated with sensory loss3, interacts with FAM134B and participates in the formation of heteromeric multi-protein clusters required for ER-phagy. Moreover, ubiquitination of ARL6IP1 promotes this process. Accordingly, disruption of Arl6ip1 in mice causes an expansion of ER sheets in sensory neurons that degenerate over time. Primary cells obtained from Arl6ip1-deficient mice or from patients display incomplete budding of ER membranes and severe impairment of ER-phagy flux. Therefore, we propose that the clustering of ubiquitinated ER-shaping proteins facilitates the dynamic remodelling of the ER during ER-phagy and is important for neuronal maintenance.
Collapse
Affiliation(s)
- Hector Foronda
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Yangxue Fu
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | | | - Hartmut T Bocker
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
- Blink AG, Jena, Germany
| | - Alexis González
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | - Eric Seemann
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Patricia Franzka
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Andrea Bock
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Ramachandra M Bhaskara
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Lutz Liebmann
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Marina E Hoffmann
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | - Istvan Katona
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Nicole Koch
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Joseph G Gleeson
- Department of Neurosciences, Rady Children's Institute for Genomic Medicine Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
- Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus C, Denmark
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Michael M Kessels
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Muriel Mari
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Ivan Dikić
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.
| | - Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
- Center for Rare Diseases, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
| |
Collapse
|
6
|
Hofbrucker-MacKenzie SA, Seemann E, Westermann M, Qualmann B, Kessels MM. Long-term depression in neurons involves temporal and ultra-structural dynamics of phosphatidylinositol-4,5-bisphosphate relying on PIP5K, PTEN and PLC. Commun Biol 2023; 6:366. [PMID: 37012315 PMCID: PMC10070498 DOI: 10.1038/s42003-023-04726-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
Synaptic plasticity involves proper establishment and rearrangement of structural and functional microdomains. Yet, visualization of the underlying lipid cues proved challenging. Applying a combination of rapid cryofixation, membrane freeze-fracturing, immunogold labeling and electron microscopy, we visualize and quantitatively determine the changes and the distribution of phosphatidylinositol-4,5-bisphosphate (PIP2) in the plasma membrane of dendritic spines and subareas thereof at ultra-high resolution. These efforts unravel distinct phases of PIP2 signals during induction of long-term depression (LTD). During the first minutes PIP2 rapidly increases in a PIP5K-dependent manner forming nanoclusters. PTEN contributes to a second phase of PIP2 accumulation. The transiently increased PIP2 signals are restricted to upper and middle spine heads. Finally, PLC-dependent PIP2 degradation provides timely termination of PIP2 cues during LTD induction. Together, this work unravels the spatial and temporal cues set by PIP2 during different phases after LTD induction and dissects the molecular mechanisms underlying the observed PIP2 dynamics.
Collapse
Affiliation(s)
- Sarah A Hofbrucker-MacKenzie
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Martin Westermann
- Center for Electron Microscopy, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
| |
Collapse
|
7
|
Tröger J, Seemann E, Heintzmann R, Kessels MM, Qualmann B. Spinal cord synaptic plasticity by GlyRβ release from receptor fields and syndapin I-dependent uptake. J Neurosci 2022; 42:JN-RM-2060-21. [PMID: 35879097 PMCID: PMC9436020 DOI: 10.1523/jneurosci.2060-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 06/23/2022] [Accepted: 07/13/2022] [Indexed: 11/21/2022] Open
Abstract
Glycine receptor-mediated inhibitory neurotransmission is key for spinal cord function. Recent observations suggested that by largely elusive mechanisms also glycinergic synapses display synaptic plasticity. We imaged receptor fields at ultra-high resolution at freeze-fractured membranes, tracked surface and internalized glycine receptors (GlyR) and studied differential regulations of GlyRβ interactions with the scaffold protein gephyrin and the F-BAR domain protein syndapin I and thereby reveal key principles of this process. S403 phosphorylation of GlyRβ, known to be triggered by synaptic signaling, caused a decoupling from gephyrin scaffolds but simultaneously promoted association of syndapin I with GlyRβ. In line, kainate-treatments used to trigger rearrangements of glycine receptors in murine syndapin I KO spinal cords (mixed sex) showed even more severe receptor field fragmentation than already observed in untreated syndapin I KO spinal cords. Syndapin I KO furthermore resulted in more dispersed receptors and increased receptor mobility also pointing out an important contribution of syndapin I in the organization of GlyRβ fields. Strikingly, syndapin I KO also led to a complete disruption of kainate-induced GlyRβ internalization. Accompanying quantitative ultra-high resolution studies in dissociated spinal cord neurons strongly suggested that the observed defects in GlyR internalization observed in syndapin I KO spinal cords are directly caused by syndapin I deficiency within murine spinal cord neurons. Together our results unveiled important mechanisms organizing and altering glycine receptor fields during both steady-state and particularly upon kainate-induced synaptic rearrangement - principles organizing and fine-tuning synaptic efficacy and plasticity of glycinergic synapses in the spinal cord.SIGNIFICANCE STATEMENTInitial observations suggested that also glycinergic synapses - key for spinal cord and brain stem functions - may display some form of synaptic plasticity. Imaging receptor fields at ultra-high resolution at freeze-fractured membranes, tracking surface and internalized glycine receptors (GlyR) and studying regulations of GlyRβ interactions we here reveal key principles of these kainate-inducible adaptations. A switch from gephyrin-mediated receptor scaffolding to syndapin I-mediated GlyRβ scaffolding and internalization allows for modulating synaptic receptor availability. In line, kainate-induced GlyRβ internalization was completely disrupted and GlyRβ receptor fields were distorted upon syndapin I KO. These results unveiled important mechanisms during both steady-state and kainate-induced alterations of synaptic GlyR fields - principles underlying synaptic efficacy and plasticity of synapses in the spinal cord.
Collapse
Affiliation(s)
- Jessica Tröger
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Rainer Heintzmann
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany; Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University, Jena, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, 07743 Jena, Germany
| |
Collapse
|
8
|
Ji Y, Koch D, González Delgado J, Günther M, Witte OW, Kessels MM, Frahm C, Qualmann B. Poststroke dendritic arbor regrowth requires the actin nucleator Cobl. PLoS Biol 2021; 19:e3001399. [PMID: 34898601 PMCID: PMC8699704 DOI: 10.1371/journal.pbio.3001399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/23/2021] [Accepted: 11/16/2021] [Indexed: 01/15/2023] Open
Abstract
Ischemic stroke is a major cause of death and long-term disability. We demonstrate that middle cerebral artery occlusion (MCAO) in mice leads to a strong decline in dendritic arborization of penumbral neurons. These defects were subsequently repaired by an ipsilateral recovery process requiring the actin nucleator Cobl. Ischemic stroke and excitotoxicity, caused by calpain-mediated proteolysis, significantly reduced Cobl levels. In an apparently unique manner among excitotoxicity-affected proteins, this Cobl decline was rapidly restored by increased mRNA expression and Cobl then played a pivotal role in poststroke dendritic arbor repair in peri-infarct areas. In Cobl knockout (KO) mice, the dendritic repair window determined to span day 2 to 4 poststroke in wild-type (WT) strikingly passed without any dendritic regrowth. Instead, Cobl KO penumbral neurons of the primary motor cortex continued to show the dendritic impairments caused by stroke. Our results thereby highlight a powerful poststroke recovery process and identified causal molecular mechanisms critical during poststroke repair. Ischemic stroke is a major cause of death and long-term disability. This study reveals that, in mice, stroke-induced damage to dendritic arborization in the area around an infarct is rapidly repaired via dendritic regrowth; this plasticity requires the actin nucleator Cobl.
Collapse
Affiliation(s)
- Yuanyuan Ji
- Institute of Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, Jena, Germany
| | - Dennis Koch
- Institute of Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, Jena, Germany
| | - Jule González Delgado
- Institute of Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, Jena, Germany
| | - Madlen Günther
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Otto W. Witte
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Michael M. Kessels
- Institute of Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, Jena, Germany
- * E-mail: (MMK); (CF); (BQ)
| | - Christiane Frahm
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
- * E-mail: (MMK); (CF); (BQ)
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, Jena, Germany
- * E-mail: (MMK); (CF); (BQ)
| |
Collapse
|
9
|
Izadi M, Seemann E, Schlobinski D, Schwintzer L, Qualmann B, Kessels MM. Functional interdependence of the actin nucleator Cobl and Cobl-like in dendritic arbor development. eLife 2021; 10:67718. [PMID: 34264190 PMCID: PMC8282341 DOI: 10.7554/elife.67718] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/30/2021] [Indexed: 12/14/2022] Open
Abstract
Local actin filament formation is indispensable for development of the dendritic arbor of neurons. We show that, surprisingly, the action of single actin filament-promoting factors was insufficient for powering dendritogenesis. Instead, this required the actin nucleator Cobl and its only evolutionary distant ancestor Cobl-like acting interdependently. This coordination between Cobl-like and Cobl was achieved by physical linkage by syndapins. Syndapin I formed nanodomains at convex plasma membrane areas at the base of protrusive structures and interacted with three motifs in Cobl-like, one of which was Ca2+/calmodulin-regulated. Consistently, syndapin I, Cobl-like’s newly identified N terminal calmodulin-binding site and the single Ca2+/calmodulin-responsive syndapin-binding motif all were critical for Cobl-like’s functions. In dendritic arbor development, local Ca2+/CaM-controlled actin dynamics thus relies on regulated and physically coordinated interactions of different F-actin formation-promoting factors and only together they have the power to bring about the sophisticated neuronal morphologies required for neuronal network formation in mammals.
Collapse
Affiliation(s)
- Maryam Izadi
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Dirk Schlobinski
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Lukas Schwintzer
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| |
Collapse
|
10
|
Pekmezovic M, Hovhannisyan H, Gresnigt MS, Iracane E, Oliveira-Pacheco J, Siscar-Lewin S, Seemann E, Qualmann B, Kalkreuter T, Müller S, Kamradt T, Mogavero S, Brunke S, Butler G, Gabaldón T, Hube B. Candida pathogens induce protective mitochondria-associated type I interferon signalling and a damage-driven response in vaginal epithelial cells. Nat Microbiol 2021; 6:643-657. [PMID: 33753919 DOI: 10.1038/s41564-021-00875-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 02/01/2021] [Indexed: 02/07/2023]
Abstract
Vaginal candidiasis is an extremely common disease predominantly caused by four phylogenetically diverse species: Candida albicans; Candida glabrata; Candida parapsilosis; and Candida tropicalis. Using a time course infection model of vaginal epithelial cells and dual RNA sequencing, we show that these species exhibit distinct pathogenicity patterns, which are defined by highly species-specific transcriptional profiles during infection of vaginal epithelial cells. In contrast, host cells exhibit a homogeneous response to all species at the early stages of infection, which is characterized by sublethal mitochondrial signalling inducing a protective type I interferon response. At the later stages, the transcriptional response of the host diverges in a species-dependent manner. This divergence is primarily driven by the extent of epithelial damage elicited by species-specific mechanisms, such as secretion of the toxin candidalysin by C. albicans. Our results uncover a dynamic, biphasic response of vaginal epithelial cells to Candida species, which is characterized by protective mitochondria-associated type I interferon signalling and a species-specific damage-driven response.
Collapse
Affiliation(s)
- Marina Pekmezovic
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Hrant Hovhannisyan
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain.,Life Sciences Department, Barcelona Supercomputing Center, Barcelona, Spain.,Mechanisms of Disease Department, Institute for Research in Biomedicine, Barcelona, Spain
| | - Mark S Gresnigt
- Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Elise Iracane
- School of Biomedical and Biomolecular Science and UCD Conway Institute of Biomolecular and Biomedical Research, Conway Institute, University College Dublin, Dublin, Ireland
| | - João Oliveira-Pacheco
- School of Biomedical and Biomolecular Science and UCD Conway Institute of Biomolecular and Biomedical Research, Conway Institute, University College Dublin, Dublin, Ireland
| | - Sofía Siscar-Lewin
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Eric Seemann
- Institute for Biochemistry I, Jena University Hospital-Friedrich Schiller University, Jena, Germany
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital-Friedrich Schiller University, Jena, Germany
| | - Till Kalkreuter
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Sylvia Müller
- Institute of Immunology, Universitätsklinikum Jena, Jena, Germany
| | - Thomas Kamradt
- Institute of Immunology, Universitätsklinikum Jena, Jena, Germany
| | - Selene Mogavero
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Geraldine Butler
- School of Biomedical and Biomolecular Science and UCD Conway Institute of Biomolecular and Biomedical Research, Conway Institute, University College Dublin, Dublin, Ireland
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain. .,Universitat Pompeu Fabra, Barcelona, Spain. .,Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain. .,Life Sciences Department, Barcelona Supercomputing Center, Barcelona, Spain. .,Mechanisms of Disease Department, Institute for Research in Biomedicine, Barcelona, Spain.
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany. .,Institute of Microbiology, Friedrich Schiller University, Jena, Germany.
| |
Collapse
|
11
|
Bocker HT, Heinrich T, Liebmann L, Hennings JC, Seemann E, Gerth M, Jakovčevski I, Preobraschenski J, Kessels MM, Westermann M, Isbrandt D, Jahn R, Qualmann B, Hübner CA. The Na+/H+ Exchanger Nhe1 Modulates Network Excitability via GABA Release. Cereb Cortex 2020; 29:4263-4276. [PMID: 30541023 DOI: 10.1093/cercor/bhy308] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 01/06/2023] Open
Abstract
Brain functions are extremely sensitive to pH changes because of the pH-dependence of proteins involved in neuronal excitability and synaptic transmission. Here, we show that the Na+/H+ exchanger Nhe1, which uses the Na+ gradient to extrude H+, is expressed at both inhibitory and excitatory presynapses. We disrupted Nhe1 specifically in mice either in Emx1-positive glutamatergic neurons or in parvalbumin-positive cells, mainly GABAergic interneurons. While Nhe1 disruption in excitatory neurons had no effect on overall network excitability, mice with disruption of Nhe1 in parvalbumin-positive neurons displayed epileptic activity. From our electrophysiological analyses in the CA1 of the hippocampus, we conclude that the disruption in parvalbumin-positive neurons impairs the release of GABA-loaded vesicles, but increases the size of GABA quanta. The latter is most likely an indirect pH-dependent effect, as Nhe1 was not expressed in purified synaptic vesicles itself. Conclusively, our data provide first evidence that Nhe1 affects network excitability via modulation of inhibitory interneurons.
Collapse
Affiliation(s)
- Hartmut T Bocker
- Institute of Human Genetics, Jena University Hospital, 07747 Jena, Germany
| | - Theresa Heinrich
- Department GMP Cell and Gene Therapy, Fraunhofer Institute for Cell Therapy and Immunology IZI, 04103 Leipzig, Germany
| | - Lutz Liebmann
- Institute of Human Genetics, Jena University Hospital, 07747 Jena, Germany
| | | | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital, 07743 Jena, Germany
| | - Melanie Gerth
- Institute of Human Genetics, Jena University Hospital, 07747 Jena, Germany
| | - Igor Jakovčevski
- Institute for Molecular and Behavioral Neuroscience, University of Cologne, 50937 Cologne, Germany, and German Center for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany
| | - Julia Preobraschenski
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital, 07743 Jena, Germany
| | - Martin Westermann
- Electron Microscopy Center, Jena University Hospital, 07747 Jena, Germany
| | - Dirk Isbrandt
- Institute for Molecular and Behavioral Neuroscience, University of Cologne, 50937 Cologne, Germany, and German Center for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany
| | - Reinhard Jahn
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, 07743 Jena, Germany
| | - Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, 07747 Jena, Germany
| |
Collapse
|
12
|
Kessels MM, Qualmann B. Interplay between membrane curvature and the actin cytoskeleton. Curr Opin Cell Biol 2020; 68:10-19. [PMID: 32927373 DOI: 10.1016/j.ceb.2020.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/10/2020] [Accepted: 08/11/2020] [Indexed: 12/26/2022]
Abstract
An intimate interplay of the plasma membrane with curvature-sensing and curvature-inducing proteins would allow for defining specific sites or nanodomains of action at the plasma membrane, for example, for protrusion, invagination, and polarization. In addition, such connections are predestined to ensure spatial and temporal order and sequences. The combined forces of membrane shapers and the cortical actin cytoskeleton might hereby in particular be required to overcome the strong resistance against membrane rearrangements in case of high plasma membrane tension or cellular turgor. Interestingly, also the opposite might be necessary, the inhibition of both membrane shapers and cytoskeletal reinforcement structures to relieve membrane tension to protect cells from membrane damage and rupturing during mechanical stress. In this review article, we discuss recent conceptual advances enlightening the interplay of plasma membrane curvature and the cortical actin cytoskeleton during endocytosis, modulations of membrane tensions, and the shaping of entire cells.
Collapse
Affiliation(s)
- Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Nonnenplan 2-4, 07743, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Nonnenplan 2-4, 07743, Jena, Germany.
| |
Collapse
|
13
|
Beer AJ, González Delgado J, Steiniger F, Qualmann B, Kessels MM. The actin nucleator Cobl organises the terminal web of enterocytes. Sci Rep 2020; 10:11156. [PMID: 32636403 PMCID: PMC7341751 DOI: 10.1038/s41598-020-66111-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 05/15/2020] [Indexed: 01/03/2023] Open
Abstract
Brush borders of intestinal epithelial cells are mandatory for nutrient uptake. Yet, which actin nucleators are crucial for forming the F-actin bundles supporting microvilli and the actin filaments of the terminal web, in which microvilli are rooted, is unknown. We show that mice lacking the actin nucleator Cobl surprisingly did not display reduced microvilli densities or changes in microvillar F-actin bundles or microvilli diameter but particularly in the duodenum displayed increased microvillar length. Interestingly, Cobl-deficient mice furthermore showed a significant widening of the terminal web. Quantitative analyses of high-resolution cryo-scanning electron microscopy (EM) of deep-etched duodenum samples revealed that Cobl is specifically important for the formation of fine filaments in the central terminal web that connect the apical structure of the terminal web underlying the plasma membrane, the microvilli rootlets and the basal structure of the terminal web with each other. Thus, the actin nucleator Cobl is critically involved in generating one of the cellular structures of the brush border-decorated apical cortex of enterocytes representing the absorptive intestinal surface.
Collapse
Affiliation(s)
- Anne J Beer
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Jule González Delgado
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Frank Steiniger
- Centre of Electron Microscopy, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
| |
Collapse
|
14
|
Tröger J, Hoischen C, Perner B, Monajembashi S, Barbotin A, Löschberger A, Eggeling C, Kessels MM, Qualmann B, Hemmerich P. Comparison of Multiscale Imaging Methods for Brain Research. Cells 2020; 9:E1377. [PMID: 32492970 PMCID: PMC7349602 DOI: 10.3390/cells9061377] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 12/11/2022] Open
Abstract
A major challenge in neuroscience is how to study structural alterations in the brain. Even small changes in synaptic composition could have severe outcomes for body functions. Many neuropathological diseases are attributable to disorganization of particular synaptic proteins. Yet, to detect and comprehensively describe and evaluate such often rather subtle deviations from the normal physiological status in a detailed and quantitative manner is very challenging. Here, we have compared side-by-side several commercially available light microscopes for their suitability in visualizing synaptic components in larger parts of the brain at low resolution, at extended resolution as well as at super-resolution. Microscopic technologies included stereo, widefield, deconvolution, confocal, and super-resolution set-ups. We also analyzed the impact of adaptive optics, a motorized objective correction collar and CUDA graphics card technology on imaging quality and acquisition speed. Our observations evaluate a basic set of techniques, which allow for multi-color brain imaging from centimeter to nanometer scales. The comparative multi-modal strategy we established can be used as a guide for researchers to select the most appropriate light microscopy method in addressing specific questions in brain research, and we also give insights into recent developments such as optical aberration corrections.
Collapse
Affiliation(s)
- Jessica Tröger
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany;
| | - Christian Hoischen
- Core Facility Imaging, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany; (C.H.); (B.P.); (S.M.)
| | - Birgit Perner
- Core Facility Imaging, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany; (C.H.); (B.P.); (S.M.)
- Molecular Genetics Lab, Leibniz Institute on Aging—Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
| | - Shamci Monajembashi
- Core Facility Imaging, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany; (C.H.); (B.P.); (S.M.)
| | - Aurélien Barbotin
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX13PJ, UK;
| | - Anna Löschberger
- Advanced Development Light Microscopy, Carl Zeiss Microscopy GmbH, Carl-Zeiss-Promenade 10, 07745 Jena, Germany;
| | - Christian Eggeling
- MRC Human Immunology Unit & Wolfson Imaging Center Oxford, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX39DS, UK;
- Dep. Biophysical Imaging, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, and Institute for Applied Optics and Biophysics, Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - Michael M. Kessels
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany;
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany;
| | - Peter Hemmerich
- Core Facility Imaging, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany; (C.H.); (B.P.); (S.M.)
| |
Collapse
|
15
|
Koch N, Koch D, Krueger S, Tröger J, Sabanov V, Ahmed T, McMillan LE, Wolf D, Montag D, Kessels MM, Balschun D, Qualmann B. Syndapin I Loss-of-Function in Mice Leads to Schizophrenia-Like Symptoms. Cereb Cortex 2020; 30:4306-4324. [DOI: 10.1093/cercor/bhaa013] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
Abstract
Schizophrenia is associated with cognitive and behavioral dysfunctions thought to reflect imbalances in neurotransmission systems. Recent screenings suggested that lack of (functional) syndapin I (PACSIN1) may be linked to schizophrenia. We therefore studied syndapin I KO mice to address the suggested causal relationship to schizophrenia and to analyze associated molecular, cellular, and neurophysiological defects. Syndapin I knockout (KO) mice developed schizophrenia-related behaviors, such as hyperactivity, reduced anxiety, reduced response to social novelty, and an exaggerated novel object response and exhibited defects in dendritic arborization in the cortex. Neuromorphogenic deficits were also observed for a schizophrenia-associated syndapin I mutant in cultured neurons and coincided with a lack of syndapin I–mediated membrane recruitment of cytoskeletal effectors. Syndapin I KO furthermore caused glutamatergic hypofunctions. Syndapin I regulated both AMPAR and NMDAR availabilities at synapses during basal synaptic activity and during synaptic plasticity—particularly striking were a complete lack of long-term potentiation and defects in long-term depression in syndapin I KO mice. These synaptic plasticity defects coincided with alterations of postsynaptic actin dynamics, synaptic GluA1 clustering, and GluA1 mobility. Both GluA1 and GluA2 were not appropriately internalized. Summarized, syndapin I KO led to schizophrenia-like behavior, and our analyses uncovered associated molecular and cellular mechanisms.
Collapse
Affiliation(s)
- Nicole Koch
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Dennis Koch
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Sarah Krueger
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Jessica Tröger
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Victor Sabanov
- Laboratory of Biological Psychology, Brain & Cognition, University of Leuven, 3000 Leuven, Belgium
| | - Tariq Ahmed
- Laboratory of Biological Psychology, Brain & Cognition, University of Leuven, 3000 Leuven, Belgium
| | - Laura E McMillan
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - David Wolf
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Dirk Montag
- Neurogenetics Lab, Leibniz Institute for Neurobiology, 39116 Magdeburg, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Detlef Balschun
- Laboratory of Biological Psychology, Brain & Cognition, University of Leuven, 3000 Leuven, Belgium
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital—Friedrich Schiller University Jena, 07743 Jena, Germany
| |
Collapse
|
16
|
Seemann E, Kessels MM, Qualmann B. Freeze-Fracture Replica Immunolabeling of Cryopreserved Membrane Compartments, Cultured Cells and Tissues. Methods Mol Biol 2020; 2169:11-25. [PMID: 32548815 DOI: 10.1007/978-1-0716-0732-9_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Membrane topology information and views of membrane-embedded protein complexes promote our understanding of membrane organization and cell biological function involving membrane compartments. Freeze-fracturing of biological membranes offers both stunning views onto integral membrane proteins and perpendicular views over wide areas of the membrane at electron microscopical resolution. This information is directly assessable for 3D analyses and quantitative analyses of the distribution of components within the membrane if it were possible to specifically detect the components of interest in the membranes. Freeze-fracture replica immunolabeling (FRIL) achieves just that. In addition, FRIL preserves antigens in their genuine cellular context free of artifacts of chemical fixation, as FRIL uses chemically unfixed cellular samples that are rapidly cryofixed. In principle, the method is not limited to integral proteins spanning the membrane. Theoretically, all membrane components should be addressable as long as they are antigenic, embedded into at least one membrane leaflet, and accessible for immunolabeling from either the intracellular or the extracellular side. Consistently, integral proteins spanning both leaflets and only partially inserted membrane proteins have been successfully identified and studied for their molecular organization and distribution in the membrane and/or in relationship to specialized membrane domains. Here we describe the freeze-fracturing of both cultured cells and tissues and the sample preparations that allowed for a successful immunogold-labeling of caveolin1 and caveolin3 or even for double-immunolabelings of caveolins with members of the syndapin family of membrane-associating and -shaping BAR domain proteins as well as with cavin 1. For this purpose samples are cryopreserved, fractured, and replicated. We also describe how the obtained stabilized membrane fractures are then cleaned to remove all loosely attached material and immunogold labeled to finally be viewed by transmission electron microscopy.
Collapse
Affiliation(s)
- Eric Seemann
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Michael M Kessels
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany.
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany.
| |
Collapse
|
17
|
Wolf D, Hofbrucker-MacKenzie SA, Izadi M, Seemann E, Steiniger F, Schwintzer L, Koch D, Kessels MM, Qualmann B. Ankyrin repeat-containing N-Ank proteins shape cellular membranes. Nat Cell Biol 2019; 21:1191-1205. [PMID: 31548610 DOI: 10.1038/s41556-019-0381-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 07/25/2019] [Indexed: 01/02/2023]
Abstract
Cells of multicellular organisms need to adopt specific morphologies. However, the molecular mechanisms bringing about membrane topology changes are far from understood-mainly because knowledge of membrane-shaping proteins that can promote local membrane curvatures is still limited. Our analyses unveiled that several members of a large, previously unrecognised protein family, which we termed N-Ank proteins, use a combination of their ankyrin repeat array and an amino (N)-terminal amphipathic helix to bind and shape membranes. Consistently, functional analyses revealed that the N-Ank protein ankycorbin (NORPEG/RAI14), which was exemplarily characterised further, plays an important, ankyrin repeat-based and N-terminal amphipathic helix-dependent role in early morphogenesis of neurons. This function furthermore required coiled coil-mediated self-assembly and manifested as ankycorbin nanodomains marked by protrusive membrane topologies. In summary, here, we unveil a class of powerful membrane shapers and thereby assign mechanistic and cell biological functions to the N-Ank protein superfamily.
Collapse
Affiliation(s)
- David Wolf
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | | | - Maryam Izadi
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Frank Steiniger
- Electron Microscopy Centre, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Lukas Schwintzer
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Dennis Koch
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Michael Manfred Kessels
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany.
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany.
| |
Collapse
|
18
|
Haag N, Schüler S, Nietzsche S, Hübner CA, Strenzke N, Qualmann B, Kessels MM. The Actin Nucleator Cobl Is Critical for Centriolar Positioning, Postnatal Planar Cell Polarity Refinement, and Function of the Cochlea. Cell Rep 2018; 24:2418-2431.e6. [DOI: 10.1016/j.celrep.2018.07.087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/18/2018] [Accepted: 07/26/2018] [Indexed: 11/26/2022] Open
|
19
|
Hou W, Nemitz S, Schopper S, Nielsen ML, Kessels MM, Qualmann B. Arginine Methylation by PRMT2 Controls the Functions of the Actin Nucleator Cobl. Dev Cell 2018; 45:262-275.e8. [PMID: 29689199 DOI: 10.1016/j.devcel.2018.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 12/23/2017] [Accepted: 03/09/2018] [Indexed: 01/15/2023]
Abstract
The complex architecture of neuronal networks in the brain requires tight control of the actin cytoskeleton. The actin nucleator Cobl is critical for neuronal morphogenesis. Here we reveal that Cobl is controlled by arginine methylation. Coprecipitations, coimmunoprecipitations, cellular reconstitutions, and in vitro reconstitutions demonstrated that Cobl associates with the protein arginine methyltransferase PRMT2 in a Src Homology 3 (SH3) domain-dependent manner and that this promotes methylation of Cobl's actin nucleating C-terminal domain. Consistently, PRMT2 phenocopied Cobl functions in both gain- and loss-of-function studies. Both PRMT2- and Cobl-promoted dendritogenesis relied on methylation. PRMT2 effects require both its catalytic domain and SH3 domain. Cobl-mediated dendritic arborization required PRMT2, complex formation with PRMT2, and PRMT2's catalytic activity. Mechanistic studies reveal that Cobl methylation is key for Cobl actin binding. Therefore, arginine methylation is a regulatory mechanism reaching beyond controlling nuclear processes. It also controls a major, cytosolic, cytoskeletal component shaping neuronal cells.
Collapse
Affiliation(s)
- Wenya Hou
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany
| | - Sabine Nemitz
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany
| | - Simone Schopper
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michael Lund Nielsen
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michael Manfred Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany.
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2-4, 07743 Jena, Germany.
| |
Collapse
|
20
|
Hertz D, Leiske MN, Wloka T, Traeger A, Hartlieb M, Kessels MM, Schubert S, Qualmann B, Schubert US. Comparison of random and gradient amino functionalized poly(2-oxazoline)s: Can the transfection efficiency be tuned by the macromolecular structure? ACTA ACUST UNITED AC 2018. [DOI: 10.1002/pola.29000] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David Hertz
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2; Jena 07743 Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
| | - Meike N. Leiske
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
- Laboratory of Organic and Macromolecular Chemistry (IOMC); Friedrich Schiller University Jena, Humboldtstraße 10; Jena 07743 Germany
| | - Thomas Wloka
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
- Laboratory of Organic and Macromolecular Chemistry (IOMC); Friedrich Schiller University Jena, Humboldtstraße 10; Jena 07743 Germany
| | - Anja Traeger
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
- Laboratory of Organic and Macromolecular Chemistry (IOMC); Friedrich Schiller University Jena, Humboldtstraße 10; Jena 07743 Germany
| | - Matthias Hartlieb
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
- Laboratory of Organic and Macromolecular Chemistry (IOMC); Friedrich Schiller University Jena, Humboldtstraße 10; Jena 07743 Germany
| | - Michael M. Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2; Jena 07743 Germany
| | - Stephanie Schubert
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
- Institute of Pharmacy, Pharmaceutical Technology, Friedrich Schiller University Jena, Otto-Schott-Straße 41; Jena 07745 Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Nonnenplan 2; Jena 07743 Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
| | - Ulrich S. Schubert
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7; Jena 07743 Germany
- Laboratory of Organic and Macromolecular Chemistry (IOMC); Friedrich Schiller University Jena, Humboldtstraße 10; Jena 07743 Germany
| |
Collapse
|
21
|
Izadi M, Schlobinski D, Lahr M, Schwintzer L, Qualmann B, Kessels MM. Cobl-like promotes actin filament formation and dendritic branching using only a single WH2 domain. J Cell Biol 2017; 217:211-230. [PMID: 29233863 PMCID: PMC5748978 DOI: 10.1083/jcb.201704071] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 09/13/2017] [Accepted: 11/01/2017] [Indexed: 02/07/2023] Open
Abstract
Local actin filament formation powers the development of the signal-receiving arbor of neurons. In this study, Izadi et al. demonstrate that Cobl-like, which bears only a single WH2 domain, mediates dendritic branching by coordinating with the F-actin–binding protein Abp1 in a Ca2+/CaM-controlled manner to control actin dynamics. Local actin filament formation powers the development of the signal-receiving arbor of neurons that underlies neuronal network formation. Yet, little is known about the molecules that drive these processes and may functionally connect them to the transient calcium pulses observed in restricted areas in the forming dendritic arbor. Here we demonstrate that Cordon-Bleu (Cobl)–like, an uncharacterized protein suggested to represent a very distantly related, evolutionary ancestor of the actin nucleator Cobl, despite having only a single G-actin–binding Wiskott–Aldrich syndrome protein Homology 2 (WH2) domain, massively promoted the formation of F-actin–rich membrane ruffles of COS-7 cells and of dendritic branches of neurons. Cobl-like hereby integrates WH2 domain functions with those of the F-actin–binding protein Abp1. Cobl-like–mediated dendritic branching is dependent on Abp1 as well as on Ca2+/calmodulin (CaM) signaling and CaM association. Calcium signaling leads to a promotion of complex formation with Cobl-like’s cofactor Abp1. Thus, Ca2+/CaM control of actin dynamics seems to be a much more broadly used principle in cell biology than previously thought.
Collapse
Affiliation(s)
- Maryam Izadi
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Dirk Schlobinski
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Maria Lahr
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Lukas Schwintzer
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| |
Collapse
|
22
|
Seemann E, Sun M, Krueger S, Tröger J, Hou W, Haag N, Schüler S, Westermann M, Huebner CA, Romeike B, Kessels MM, Qualmann B. Deciphering caveolar functions by syndapin III KO-mediated impairment of caveolar invagination. eLife 2017; 6. [PMID: 29202928 PMCID: PMC5716666 DOI: 10.7554/elife.29854] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 11/14/2017] [Indexed: 12/11/2022] Open
Abstract
Several human diseases are associated with a lack of caveolae. Yet, the functions of caveolae and the molecular mechanisms critical for shaping them still are debated. We show that muscle cells of syndapin III KO mice show severe reductions of caveolae reminiscent of human caveolinopathies. Yet, different from other mouse models, the levels of the plasma membrane-associated caveolar coat proteins caveolin3 and cavin1 were both not reduced upon syndapin III KO. This allowed for dissecting bona fide caveolar functions from those supported by mere caveolin presence and also demonstrated that neither caveolin3 nor caveolin3 and cavin1 are sufficient to form caveolae. The membrane-shaping protein syndapin III is crucial for caveolar invagination and KO rendered the cells sensitive to membrane tensions. Consistent with this physiological role of caveolae in counterpoising membrane tensions, syndapin III KO skeletal muscles showed pathological parameters upon physical exercise that are also found in CAVEOLIN3 mutation-associated muscle diseases.
Collapse
Affiliation(s)
- Eric Seemann
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Minxuan Sun
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Sarah Krueger
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Jessica Tröger
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Wenya Hou
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Natja Haag
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Susann Schüler
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Martin Westermann
- Electron Microscopy Center, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Christian A Huebner
- Institute for Human Genetics, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Bernd Romeike
- Institute of Pathology, Division of Neuropathology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Michael M Kessels
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| |
Collapse
|
23
|
Sporny M, Guez-Haddad J, Kreusch A, Shakartzi S, Neznansky A, Cross A, Isupov MN, Qualmann B, Kessels MM, Opatowsky Y. Structural History of Human SRGAP2 Proteins. Mol Biol Evol 2017; 34:1463-1478. [PMID: 28333212 PMCID: PMC5435084 DOI: 10.1093/molbev/msx094] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In the development of the human brain, human-specific genes are considered to play key roles, conferring its unique advantages and vulnerabilities. At the time of Homo lineage divergence from Australopithecus, SRGAP2C gradually emerged through a process of serial duplications and mutagenesis from ancestral SRGAP2A (3.4–2.4 Ma). Remarkably, ectopic expression of SRGAP2C endows cultured mouse brain cells, with human-like characteristics, specifically, increased dendritic spine length and density. To understand the molecular mechanisms underlying this change in neuronal morphology, we determined the structure of SRGAP2A and studied the interplay between SRGAP2A and SRGAP2C. We found that: 1) SRGAP2A homo-dimerizes through a large interface that includes an F-BAR domain, a newly identified F-BAR extension (Fx), and RhoGAP-SH3 domains. 2) SRGAP2A has an unusual inverse geometry, enabling associations with lamellipodia and dendritic spine heads in vivo, and scaffolding of membrane protrusions in cell culture. 3) As a result of the initial partial duplication event (∼3.4 Ma), SRGAP2C carries a defective Fx-domain that severely compromises its solubility and membrane-scaffolding ability. Consistently, SRGAP2A:SRAGP2C hetero-dimers form, but are insoluble, inhibiting SRGAP2A activity. 4) Inactivation of SRGAP2A is sensitive to the level of hetero-dimerization with SRGAP2C. 5) The primal form of SRGAP2C (P-SRGAP2C, existing between ∼3.4 and 2.4 Ma) is less effective in hetero-dimerizing with SRGAP2A than the modern SRGAP2C, which carries several substitutions (from ∼2.4 Ma). Thus, the genetic mutagenesis phase contributed to modulation of SRGAP2A’s inhibition of neuronal expansion, by introducing and improving the formation of inactive SRGAP2A:SRGAP2C hetero-dimers, indicating a stepwise involvement of SRGAP2C in human evolutionary history.
Collapse
Affiliation(s)
- Michael Sporny
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Julia Guez-Haddad
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Annett Kreusch
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Sivan Shakartzi
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Avi Neznansky
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Alice Cross
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Michail N Isupov
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Michael M Kessels
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Yarden Opatowsky
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| |
Collapse
|
24
|
Wales P, Schuberth CE, Aufschnaiter R, Fels J, García-Aguilar I, Janning A, Dlugos CP, Schäfer-Herte M, Klingner C, Wälte M, Kuhlmann J, Menis E, Hockaday Kang L, Maier KC, Hou W, Russo A, Higgs HN, Pavenstädt H, Vogl T, Roth J, Qualmann B, Kessels MM, Martin DE, Mulder B, Wedlich-Söldner R. Calcium-mediated actin reset (CaAR) mediates acute cell adaptations. eLife 2016; 5. [PMID: 27919320 PMCID: PMC5140269 DOI: 10.7554/elife.19850] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 11/14/2016] [Indexed: 12/24/2022] Open
Abstract
Actin has well established functions in cellular morphogenesis. However, it is not well understood how the various actin assemblies in a cell are kept in a dynamic equilibrium, in particular when cells have to respond to acute signals. Here, we characterize a rapid and transient actin reset in response to increased intracellular calcium levels. Within seconds of calcium influx, the formin INF2 stimulates filament polymerization at the endoplasmic reticulum (ER), while cortical actin is disassembled. The reaction is then reversed within a few minutes. This Calcium-mediated actin reset (CaAR) occurs in a wide range of mammalian cell types and in response to many physiological cues. CaAR leads to transient immobilization of organelles, drives reorganization of actin during cell cortex repair, cell spreading and wound healing, and induces long-lasting changes in gene expression. Our findings suggest that CaAR acts as fundamental facilitator of cellular adaptations in response to acute signals and stress. DOI:http://dx.doi.org/10.7554/eLife.19850.001 Our skeleton plays a vital role in giving shape and structure to our body, it also allows us to make coordinated movements. Similarly, each cell contains a microscopic network of structures and supports called the cytoskeleton that helps cells to adopt specific shapes and is crucial for them to move around. Unlike our skeleton, which is relatively unchanging, the cytoskeleton of each cell constantly changes and adapts to the specific needs of the cell. One part of the cytoskeleton is a dense, flexible meshwork of fibers called the cortex that lies just beneath the surface of the cell. The cortex is constructed using a protein called actin, and many of these proteins join together to form each fiber. When cells need to adapt rapidly to an injury or other sudden changes in their environment they activate a so-called stress response. This response often begins with a rapid increase in the amount of calcium ions inside a cell, which can then trigger changes in actin organization. However, it is not clear how cells under stress are able to globally remodel their actin cytoskeleton without compromising stability and integrity of the cortex. Wales, Schuberth, Aufschnaiter et al. used a range of mammalian cells to investigate how actin responds to stress signals. All cells responded to the resulting influx of calcium ions by deconstructing large parts of the actin cortex and simultaneously forming actin filaments near the center of the cell. Wales, Schuberth, Aufschnaiter et al. termed this response calcium-mediated actin reset (CaAR), as it lasted for only a few minutes before the actin cortex reformed. The experiments show that a protein called INF2 controls CaAR by rapidly removing actin from the cortex and forming new filaments near a cell compartment called the endoplasmic reticulum. CaAR allows cells to rapidly and drastically alter the cortex in response to stress. The experiments also show that this sudden shift in actin can change the activity of certain genes, leading to longer-term effects on the cell. The findings of Wales, Schuberth, Aufschnaiter et al. suggest that calcium ions globally regulate the actin cytoskeleton and hence cell shape and movement under stress. This could be relevant for many important processes and conditions such as wound healing, inflammation and cancer. A future challenge will be to understand the role of CaAR in these processes. DOI:http://dx.doi.org/10.7554/eLife.19850.002
Collapse
Affiliation(s)
- Pauline Wales
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Christian E Schuberth
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Roland Aufschnaiter
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Johannes Fels
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | | | - Annette Janning
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Christopher P Dlugos
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany.,Medical Clinic D, University Clinic of Muenster, Muenster, Germany
| | - Marco Schäfer-Herte
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Christoph Klingner
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany.,AG Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Munich, Germany
| | - Mike Wälte
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Julian Kuhlmann
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Ekaterina Menis
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Laura Hockaday Kang
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| | - Kerstin C Maier
- Department of Biochemistry, University of Munich, Munich, Germany
| | - Wenya Hou
- Institute of Biochemistry I, Friedrich Schiller University Jena, Jena, Germany
| | - Antonella Russo
- Institute of Immunology, University of Münster, Münster, Germany
| | - Henry N Higgs
- Department of Biochemistry, Dartmouth Medical School, Hanover, United States
| | | | - Thomas Vogl
- Institute of Immunology, University of Münster, Münster, Germany
| | - Johannes Roth
- Institute of Immunology, University of Münster, Münster, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Friedrich Schiller University Jena, Jena, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Friedrich Schiller University Jena, Jena, Germany
| | - Dietmar E Martin
- Department of Biochemistry, University of Munich, Munich, Germany
| | - Bela Mulder
- Theory of Biological Matter, FOM Institute AMOLF, Amsterdam, Netherlands
| | - Roland Wedlich-Söldner
- Institute of Cell Dynamics and Imaging, University of Muenster, Muenster, Germany.,Cells-In-Motion Cluster of Excellence (EXC1003 - CiM), University of Münster, Muenster, Germany
| |
Collapse
|
25
|
Lu-Walther HW, Hou W, Kielhorn M, Arai Y, Nagai T, Kessels MM, Qualmann B, Heintzmann R. Nonlinear Structured Illumination Using a Fluorescent Protein Activating at the Readout Wavelength. PLoS One 2016; 11:e0165148. [PMID: 27783656 PMCID: PMC5082623 DOI: 10.1371/journal.pone.0165148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 10/09/2016] [Indexed: 11/18/2022] Open
Abstract
Structured illumination microscopy (SIM) is a wide-field technique in fluorescence microscopy that provides fast data acquisition and two-fold resolution improvement beyond the Abbe limit. We observed a further resolution improvement using the nonlinear emission response of a fluorescent protein. We demonstrated a two-beam nonlinear structured illumination microscope by introducing only a minor change into the system used for linear SIM (LSIM). To achieve the required nonlinear dependence in nonlinear SIM (NL-SIM) we exploited the photoswitching of the recently introduced fluorophore Kohinoor. It is particularly suitable due to its positive contrast photoswitching characteristics. Contrary to other reversibly photoswitchable fluorescent proteins which only have high photostability in living cells, Kohinoor additionally showed little degradation in fixed cells over many switching cycles.
Collapse
Affiliation(s)
| | - Wenya Hou
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, Jena, Germany
| | | | - Yoshiyuki Arai
- The Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Michael M. Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich Schiller University Jena, Jena, Germany
| | - Rainer Heintzmann
- Leibniz Institute of Photonic Technology, Jena, Germany
- Institute of Physical Chemistry, Abbe Center of Photonics, Friedrich-Schiller-University Jena, Jena, Germany
- * E-mail:
| |
Collapse
|
26
|
Zobel T, Brinkmann K, Koch N, Schneider K, Seemann E, Fleige A, Qualmann B, Kessels MM, Bogdan S. Cooperative functions of the two F-BAR proteins Cip4 and Nostrin in the regulation of E-cadherin in epithelial morphogenesis. J Cell Sci 2016; 128:499-515. [PMID: 25413347 DOI: 10.1242/jcs.155929] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
F-BAR proteins are prime candidates to regulate membrane curvature and dynamics during different developmental processes. Here, we analyzed nostrin, a so-far-unknown Drosophila melanogaster F-BAR protein related to Cip4. Genetic analyses revealed a strong synergism between nostrin and cip4 functions.Whereas single mutant flies are viable and fertile, combined loss of nostrin and cip4 results in reduced viability and fertility. Double mutant escaper flies show enhanced wing polarization defects and females exhibit strong egg chamber encapsulation defects. Live imaging analysis suggests that the observed phenotypes are caused by an impaired turnover of E-cadherin at the membrane. Simultaneous knockdown of Cip4 and Nostrin strongly increases the formation of tubular E-cadherin vesicles at adherens junctions. Cip4 and Nostrin localize at distinct membrane subdomains. Both proteins prefer similar membrane curvatures but seem to form distinct membrane coats and do not heterooligomerize. Our data suggest an important synergistic function of both F-BAR proteins in membrane dynamics. We propose a cooperative recruitment model, in which Cip4 initially promotes membrane invagination and early-actin-based endosomal motility, and Nostrin makes contacts with microtubules through the kinesin Khc-73 for trafficking of recycling endosomes.
Collapse
|
27
|
Hou W, Izadi M, Nemitz S, Haag N, Kessels MM, Qualmann B. The Actin Nucleator Cobl Is Controlled by Calcium and Calmodulin. PLoS Biol 2015; 13:e1002233. [PMID: 26334624 PMCID: PMC4559358 DOI: 10.1371/journal.pbio.1002233] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 07/23/2015] [Indexed: 01/10/2023] Open
Abstract
Actin nucleation triggers the formation of new actin filaments and has the power to shape cells but requires tight control in order to bring about proper morphologies. The regulation of the members of the novel class of WASP Homology 2 (WH2) domain-based actin nucleators, however, thus far has largely remained elusive. Our study reveals signal cascades and mechanisms regulating Cordon-Bleu (Cobl). Cobl plays some, albeit not fully understood, role in early arborization of neurons and nucleates actin by a mechanism that requires a combination of all three of its actin monomer–binding WH2 domains. Our experiments reveal that Cobl is regulated by Ca2+ and multiple, direct associations of the Ca2+ sensor Calmodulin (CaM). Overexpression analyses and rescue experiments of Cobl loss-of-function phenotypes with Cobl mutants in primary neurons and in tissue slices demonstrated the importance of CaM binding for Cobl’s functions. Cobl-induced dendritic branch initiation was preceded by Ca2+ signals and coincided with local F-actin and CaM accumulations. CaM inhibitor studies showed that Cobl-mediated branching is strictly dependent on CaM activity. Mechanistic studies revealed that Ca2+/CaM modulates Cobl’s actin binding properties and furthermore promotes Cobl’s previously identified interactions with the membrane-shaping F-BAR protein syndapin I, which accumulated with Cobl at nascent dendritic protrusion sites. The findings of our study demonstrate a direct regulation of an actin nucleator by Ca2+/CaM and reveal that the Ca2+/CaM-controlled molecular mechanisms we discovered are crucial for Cobl’s cellular functions. By unveiling the means of Cobl regulation and the mechanisms, by which Ca2+/CaM signals directly converge on a cellular effector promoting actin filament formation, our work furthermore sheds light on how local Ca2+ signals steer and power branch initiation during early arborization of nerve cells—a key process in neuronal network formation. The calcium sensor calmodulin directly regulates the actin filament-promoting factor Cobl to help shape the complex architecture of neurons underlying neuronal network formation. The organization and the formation of new actin filaments by polymerization of actin monomers has the power to shape cells. The rate-limiting step in actin polymerization is “nucleation”—a process during which the first actin monomers are assembled with the help of actin nucleators. This nucleation step requires tight temporal and spatial control in order to achieve proper cell morphologies. Here, we analyse signaling cascades and mechanisms regulating the actin nucleator Cobl, which is crucial for the formation of dendritic arbors of nerve cells—a key process in neuronal network formation. We show that the calcium (Ca2+)-binding signaling component calmodulin (CaM) binds to Cobl and regulates its functions. Using 3-D time-lapse analyses of developing neurons, we visualized how Cobl works. We observed local accumulation of CaM, Cobl, actin, and syndapin I—a membrane-shaping protein—at dendritic branch initiation sites. We find that Ca2+/CaM modulates Cobl’s actin-binding properties and promotes its interactions with syndapin I, which then serves as a membrane anchor for Cobl. In summary, we i) show a direct regulation of the actin nucleator Cobl by Ca2+/CaM, ii) demonstrate that the molecular mechanisms we discovered are crucial for shaping nerve cells, and iii) underscore how local Ca2+ signals steer and power branch initiation during early arborization of neurons.
Collapse
Affiliation(s)
- Wenya Hou
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Maryam Izadi
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Sabine Nemitz
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Natja Haag
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Michael M. Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
- * E-mail: (BQ); (MMK)
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
- * E-mail: (BQ); (MMK)
| |
Collapse
|
28
|
Abstract
A plethora of cell biological processes involve modulations of cellular membranes. By using extended lipid-binding interfaces, some proteins have the power to shape membranes by attaching to them. Among such membrane shapers, the superfamily of Bin-Amphiphysin-Rvs (BAR) domain proteins has recently taken center stage. Extensive structural work on BAR domains has revealed a common curved fold that can serve as an extended membrane-binding interface to modulate membrane topologies and has allowed the grouping of the BAR domain superfamily into subfamilies with structurally slightly distinct BAR domain subtypes (N-BAR, BAR, F-BAR and I-BAR). Most BAR superfamily members are expressed in the mammalian nervous system. Neurons are elaborately shaped and highly compartmentalized cells. Therefore, analyses of synapse formation and of postsynaptic reorganization processes (synaptic plasticity) - a basis for learning and memory formation - has unveiled important physiological functions of BAR domain superfamily members. These recent advances, furthermore, have revealed that the functions of BAR domain proteins include different aspects. These functions are influenced by the often complex domain organization of BAR domain proteins. In this Commentary, we review these recent insights and propose to classify BAR domain protein functions into (1) membrane shaping, (2) physical integration, (3) action through signaling components, and (4) suppression of other BAR domain functions.
Collapse
Affiliation(s)
- Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University, Nonnenplan 2-4, 07743 Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University, Nonnenplan 2-4, 07743 Jena, Germany
| |
Collapse
|
29
|
Varga RE, Khundadze M, Damme M, Nietzsche S, Hoffmann B, Stauber T, Koch N, Hennings JC, Franzka P, Huebner AK, Kessels MM, Biskup C, Jentsch TJ, Qualmann B, Braulke T, Kurth I, Beetz C, Hübner CA. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11. PLoS Genet 2015; 11:e1005454. [PMID: 26284655 PMCID: PMC4540459 DOI: 10.1371/journal.pgen.1005454] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 07/20/2015] [Indexed: 12/04/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs). Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice. Autophagy is a degradative pathway for the removal and subsequent recycling of dysfunctional intracellular components. The material destined for degradation is initially enclosed by a double membrane, the autophagosome. In autolysosomes, which result from fusion of autophagosomes with lysosomes, the material is finally broken down. Recent in vitro data suggested that the protein Spatacsin plays a pivotal role in the regeneration of lysosomes from autolysosomes. Spatacsin is encoded by SPG11, the most common gene mutated in autosomal recessive hereditary spastic paraplegia. Here we show that mice devoid of Spatacsin develop symptoms consistent with spastic paraplegia and progressively loose cortical motoneurons and Purkinje cells. In these mice degenerating neurons have a reduced number of lysosomes available for fusion with autophagosomes and consequently accumulate autolysosome-derived material over time. In the long term this causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells.
Collapse
Affiliation(s)
- Rita-Eva Varga
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
- Institute of Clinical Chemistry, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Mukhran Khundadze
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Markus Damme
- Biochemical Institute, University of Kiel, Kiel, Germany
| | - Sandor Nietzsche
- Electron Microscopy Center, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Birgit Hoffmann
- Biomolecular Photonics Group, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Tobias Stauber
- Leibniz-Institut für Molekulare Pharmakologie (FMP) und Max-Delbrück Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Nicole Koch
- Institute of Biochemistry I, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - J. Christopher Hennings
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Patricia Franzka
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Antje K. Huebner
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Michael M. Kessels
- Institute of Biochemistry I, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christoph Biskup
- Biomolecular Photonics Group, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Thomas J. Jentsch
- Leibniz-Institut für Molekulare Pharmakologie (FMP) und Max-Delbrück Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Thomas Braulke
- Department of Biochemistry, Children’s Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christian Beetz
- Institute of Clinical Chemistry, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christian A. Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
- * E-mail:
| |
Collapse
|
30
|
Zobel T, Brinkmann K, Koch N, Schneider K, Seemann E, Fleige A, Qualmann B, Kessels MM, Bogdan S. Cooperative functions of the two F-BAR proteins Cip4 and Nostrin in the regulation of E-cadherin in epithelial morphogenesis. J Cell Sci 2015; 128:1453. [PMID: 25829514 DOI: 10.1242/jcs.170944] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
31
|
Beetz C, Koch N, Khundadze M, Zimmer G, Nietzsche S, Hertel N, Huebner AK, Mumtaz R, Schweizer M, Dirren E, Karle KN, Irintchev A, Alvarez V, Redies C, Westermann M, Kurth I, Deufel T, Kessels MM, Qualmann B, Hübner CA. A spastic paraplegia mouse model reveals REEP1-dependent ER shaping. J Clin Invest 2014. [DOI: 10.1172/jci76634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
32
|
Koch N, Kobler O, Thomas U, Qualmann B, Kessels MM. Terminal axonal arborization and synaptic bouton formation critically rely on abp1 and the arp2/3 complex. PLoS One 2014; 9:e97692. [PMID: 24841972 PMCID: PMC4026379 DOI: 10.1371/journal.pone.0097692] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 04/23/2014] [Indexed: 01/12/2023] Open
Abstract
Neuronal network formation depends on properly timed and localized generation of presynaptic as well as postsynaptic structures. Although of utmost importance for understanding development and plasticity of the nervous system and neurodegenerative diseases, the molecular mechanisms that ensure the fine-control needed for coordinated establishment of pre- and postsynapses are still largely unknown. We show that the F-actin-binding protein Abp1 is prominently expressed in the Drosophila nervous system and reveal that Abp1 is an important regulator in shaping glutamatergic neuromuscular junctions (NMJs) of flies. STED microscopy shows that Abp1 accumulations can be found in close proximity of synaptic vesicles and at the cell cortex in nerve terminals. Abp1 knock-out larvae have locomotion defects and underdeveloped NMJs that are characterized by a reduced number of both type Ib synaptic boutons and branches of motornerve terminals. Abp1 is able to indirectly trigger Arp2/3 complex-mediated actin nucleation and interacts with both WASP and Scar. Consistently, Arp2 and Arp3 loss-of-function also resulted in impairments of bouton formation and arborization at NMJs, i.e. fully phenocopied abp1 knock-out. Interestingly, neuron- and muscle-specific rescue experiments revealed that synaptic bouton formation critically depends on presynaptic Abp1, whereas the NMJ branching defects can be compensated for by restoring Abp1 functions at either side. In line with this presynaptic importance of Abp1, also presynaptic Arp2 and Arp3 are crucial for the formation of type Ib synaptic boutons. Interestingly, presynaptic Abp1 functions in NMJ formation were fully dependent on the Arp2/3 complex, as revealed by suppression of Abp1-induced synaptic bouton formation and branching of axon terminals upon presynaptic Arp2 RNAi. These data reveal that Abp1 and Arp2/3 complex-mediated actin cytoskeletal dynamics drive both synaptic bouton formation and NMJ branching. Our data furthermore shed light on an intense bidirectional functional crosstalk between pre- and postsynapses during the development of synaptic contacts.
Collapse
Affiliation(s)
- Nicole Koch
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
- Research Group Membrane Trafficking and Cytoskeleton, Department of Neurochemistry & Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Oliver Kobler
- Research Group Functional Genetics of the Synapse, Department of Neurochemistry & Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ulrich Thomas
- Research Group Functional Genetics of the Synapse, Department of Neurochemistry & Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- * E-mail: (UT); (BQ); (MMK)
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
- * E-mail: (UT); (BQ); (MMK)
| | - Michael M. Kessels
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
- Research Group Membrane Trafficking and Cytoskeleton, Department of Neurochemistry & Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- * E-mail: (UT); (BQ); (MMK)
| |
Collapse
|
33
|
Schneider K, Seemann E, Liebmann L, Ahuja R, Koch D, Westermann M, Hübner CA, Kessels MM, Qualmann B. ProSAP1 and membrane nanodomain-associated syndapin I promote postsynapse formation and function. ACTA ACUST UNITED AC 2014; 205:197-215. [PMID: 24751538 PMCID: PMC4003247 DOI: 10.1083/jcb.201307088] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
ProSAP1/Shank2 and syndapin I–enriched membrane nanodomains are important spatial cues and organizing platforms that shape dendritic membranes into synaptic compartments. Insights into mechanisms coordinating membrane remodeling, local actin nucleation, and postsynaptic scaffolding during postsynapse formation are important for understanding vertebrate brain function. Gene knockout and RNAi in individual neurons reveal that the F-BAR protein syndapin I is a crucial postsynaptic coordinator in formation of excitatory synapses. Syndapin I deficiency caused significant reductions of synapse and dendritic spine densities. These syndapin I functions reflected direct, SH3 domain–mediated associations and functional interactions with ProSAP1/Shank2. They furthermore required F-BAR domain-mediated membrane binding. Ultra-high-resolution imaging of specifically membrane-associated, endogenous syndapin I at membranes of freeze-fractured neurons revealed that membrane-bound syndapin I preferentially occurred in spines and formed clusters at distinct postsynaptic membrane subareas. Postsynaptic syndapin I deficiency led to reduced frequencies of miniature excitatory postsynaptic currents, i.e., to defects in synaptic transmission phenocopying ProSAP1/Shank2 knockout, and impairments in proper synaptic ProSAP1/Shank2 distribution. Syndapin I–enriched membrane nanodomains thus seem to be important spatial cues and organizing platforms, shaping dendritic membrane areas into synaptic compartments.
Collapse
Affiliation(s)
- Katharina Schneider
- Institute for Biochemistry I, 2 Institute for Human Genetics, and 3 Electron Microscopy Center, Jena University Hospital, Friedrich Schiller University Jena, 07743 Jena, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Del Pino I, Koch D, Schemm R, Qualmann B, Betz H, Paarmann I. Proteomic analysis of glycine receptor β subunit (GlyRβ)-interacting proteins: evidence for syndapin I regulating synaptic glycine receptors. J Biol Chem 2014; 289:11396-11409. [PMID: 24509844 DOI: 10.1074/jbc.m113.504860] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Glycine receptors (GlyRs) mediate inhibitory neurotransmission in spinal cord and brainstem. They are clustered at inhibitory postsynapses via a tight interaction of their β subunits (GlyRβ) with the scaffolding protein gephyrin. In an attempt to isolate additional proteins interacting with GlyRβ, we performed pulldown experiments with rat brain extracts using a glutathione S-transferase fusion protein encompassing amino acids 378-455 of the large intracellular loop of GlyRβ as bait. This identified syndapin I (SdpI) as a novel interaction partner of GlyRβ that coimmunoprecipitates with native GlyRs from brainstem extracts. Both SdpI and SdpII bound efficiently to the intracellular loop of GlyRβ in vitro and colocalized with GlyRβ upon coexpression in COS-7 cells. The SdpI-binding site was mapped to a proline-rich sequence of 22 amino acids within the intracellular loop of GlyRβ. Deletion and point mutation analysis disclosed that SdpI binding to GlyRβ is Src homology 3 domain-dependent. In cultured rat spinal cord neurons, SdpI immunoreactivity was found to partially colocalize with marker proteins of inhibitory and excitatory synapses. When SdpI was acutely knocked down in cultured spinal cord neurons by viral miRNA expression, postsynaptic GlyR clusters were significantly reduced in both size and number. Similar changes in GlyR cluster properties were found in spinal cultures from SdpI-deficient mice. Our results are consistent with a role of SdpI in the trafficking and/or cytoskeletal anchoring of synaptic GlyRs.
Collapse
Affiliation(s)
- Isabel Del Pino
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, D-60438 Frankfurt/Main
| | - Dennis Koch
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, D-07743 Jena
| | - Rudolf Schemm
- Department for Theoretical and Computational Biophysics, Max-Planck-Institute for Biophysical Chemistry, D-37077 Göttingen, and
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, D-07743 Jena
| | - Heinrich Betz
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, D-60438 Frankfurt/Main,; Max-Planck Institute for Medical Research, 69120 Heidelberg, Germany.
| | - Ingo Paarmann
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, D-60438 Frankfurt/Main,.
| |
Collapse
|
35
|
Khundadze M, Kollmann K, Koch N, Biskup C, Nietzsche S, Zimmer G, Hennings JC, Huebner AK, Symmank J, Jahic A, Ilina EI, Karle K, Schöls L, Kessels M, Braulke T, Qualmann B, Kurth I, Beetz C, Hübner CA. A hereditary spastic paraplegia mouse model supports a role of ZFYVE26/SPASTIZIN for the endolysosomal system. PLoS Genet 2013; 9:e1003988. [PMID: 24367272 PMCID: PMC3868532 DOI: 10.1371/journal.pgen.1003988] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 10/14/2013] [Indexed: 12/26/2022] Open
Abstract
Hereditary spastic paraplegias (HSPs) are characterized by progressive weakness and spasticity of the legs because of the degeneration of cortical motoneuron axons. SPG15 is a recessively inherited HSP variant caused by mutations in the ZFYVE26 gene and is additionally characterized by cerebellar ataxia, mental decline, and progressive thinning of the corpus callosum. ZFYVE26 encodes the FYVE domain-containing protein ZFYVE26/SPASTIZIN, which has been suggested to be associated with the newly discovered adaptor protein 5 (AP5) complex. We show that Zfyve26 is broadly expressed in neurons, associates with intracellular vesicles immunopositive for the early endosomal marker EEA1, and co-fractionates with a component of the AP5 complex. As the function of ZFYVE26 in neurons was largely unknown, we disrupted Zfyve26 in mice. Zfyve26 knockout mice do not show developmental defects but develop late-onset spastic paraplegia with cerebellar ataxia confirming that SPG15 is caused by ZFYVE26 deficiency. The morphological analysis reveals axon degeneration and progressive loss of both cortical motoneurons and Purkinje cells in the cerebellum. Importantly, neuron loss is preceded by accumulation of large intraneuronal deposits of membrane-surrounded material, which co-stains with the lysosomal marker Lamp1. A density gradient analysis of brain lysates shows an increase of Lamp1-positive membrane compartments with higher densities in Zfyve26 knockout mice. Increased levels of lysosomal enzymes in brains of aged knockout mice further support an alteration of the lysosomal compartment upon disruption of Zfyve26. We propose that SPG15 is caused by an endolysosomal membrane trafficking defect, which results in endolysosomal dysfunction. This appears to be particularly relevant in neurons with highly specialized neurites such as cortical motoneurons and Purkinje cells. Hereditary spastic paraplegias (HSPs) are inherited disorders characterized by progressive weakness and spasticity of the legs. In HSP patients, nerve fibers connecting cortical motoneurons with spinal cord neurons are progressively lost. HSP subtype 15 (SPG15) is caused by mutations in ZFYVE26, and is characterized by additional cerebellar symptoms. We show that the Zfyve26 protein is broadly expressed in the brain. At the subcellular level Zfyve26 localizes to an intracellular compartment in the endocytic pathway from the plasma membrane to lysosomes, which is part of the degradative system of the cell. Closely resembling the human disease, mice deficient for Zfyve26 develop a progressive spastic gait disorder with cerebellar symptoms and degeneration of both neurons of the motor cortex and Purkinje cells in the cerebellum. Importantly, this degeneration is characterized by the intracellular accumulation of abnormal deposits, which stain positive for the lysosomal marker Lamp1. As Zfyve26 has been shown to interact with the newly identified adaptor complex AP5, which is supposed to be involved in cargo trafficking in the endolysosomal compartment, endolysosomal dysfunction may be caused by a targeting defect upon disruption of Zfyve26. As highly specialized neurons like cortical motoneurons and cerebellar Purkinje cells degenerate, these neurons appear to be particularly dependent on proper endolysosomal function.
Collapse
Affiliation(s)
- Mukhran Khundadze
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Katrin Kollmann
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicole Koch
- Institute of Biochemistry I, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christoph Biskup
- Department of Biomolecular Photonics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Sandor Nietzsche
- Electron Microscopy Center, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Geraldine Zimmer
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - J. Christopher Hennings
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Antje K. Huebner
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Judit Symmank
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Amir Jahic
- Institute of Clinical Chemistry, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Elena I. Ilina
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Kathrin Karle
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Ludger Schöls
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Michael Kessels
- Institute of Biochemistry I, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Thomas Braulke
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christian Beetz
- Institute of Clinical Chemistry, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christian A. Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
- * E-mail:
| |
Collapse
|
36
|
Nolze A, Schneider J, Keil R, Lederer M, Hüttelmaier S, Kessels MM, Qualmann B, Hatzfeld M. FMRP regulates actin filament organization via the armadillo protein p0071. RNA 2013; 19:1483-96. [PMID: 24062571 PMCID: PMC3851716 DOI: 10.1261/rna.037945.112] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Loss of fragile X mental retardation protein (FMRP) causes synaptic dysfunction and intellectual disability. FMRP is an RNA-binding protein that controls the translation or turnover of a subset of mRNAs. Identifying these target transcripts is an important step toward understanding the pathology of the disease. Here, we show that FMRP regulates actin organization and neurite outgrowth via the armadillo protein p0071. In mouse embryonic fibroblasts (MEFs) lacking FMRP (Fmr1-), the actin cytoskeleton was markedly reorganized with reduced stress fibers and F-actin/G-actin ratios compared to fibroblasts re-expressing the protein. FMRP interfered with the translation of the p0071 mRNA in a 3'-UTR-dependent manner. Accordingly, FMRP-depleted cells revealed elevated levels of p0071 protein. The knockdown of p0071 in Fmr1- fibroblasts restored stress fibers and an elongated cell shape, thus rescuing the Fmr1- phenotype, whereas overexpression of p0071 in Fmr1+ cells mimicked the Fmr1- phenotype. Moreover, p0071 and FMRP regulated neurite outgrowth and branching in a diametrically opposed way in agreement with the negative regulation of p0071 by FMRP. These results identify p0071 as an important and novel FMRP target and strongly suggest that impaired actin cytoskeletal functions mediated by an excess of p0071 are key aspects underlying the fragile X syndrome.
Collapse
Affiliation(s)
- Alexander Nolze
- Institute of Molecular Medicine, Division of Pathobiochemistry, Martin-Luther-University of Halle, 06114 Halle, Germany
| | - Jacqueline Schneider
- Institute for Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, 07743 Jena, Germany
| | - René Keil
- Institute of Molecular Medicine, Division of Pathobiochemistry, Martin-Luther-University of Halle, 06114 Halle, Germany
| | - Marcell Lederer
- Institute of Molecular Medicine, Division of Cell Biology, Martin-Luther-University of Halle, 06120 Halle, Germany
| | - Stefan Hüttelmaier
- Institute of Molecular Medicine, Division of Cell Biology, Martin-Luther-University of Halle, 06120 Halle, Germany
| | - Michael M. Kessels
- Institute for Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital–Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Mechthild Hatzfeld
- Institute of Molecular Medicine, Division of Pathobiochemistry, Martin-Luther-University of Halle, 06114 Halle, Germany
- Corresponding authorE-mail
| |
Collapse
|
37
|
Beetz C, Koch N, Khundadze M, Zimmer G, Nietzsche S, Hertel N, Huebner AK, Mumtaz R, Schweizer M, Dirren E, Karle KN, Irintchev A, Alvarez V, Redies C, Westermann M, Kurth I, Deufel T, Kessels MM, Qualmann B, Hübner CA. A spastic paraplegia mouse model reveals REEP1-dependent ER shaping. J Clin Invest 2013; 123:4273-82. [PMID: 24051375 DOI: 10.1172/jci65665] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 07/03/2013] [Indexed: 11/17/2022] Open
Abstract
Axonopathies are a group of clinically diverse disorders characterized by the progressive degeneration of the axons of specific neurons. In hereditary spastic paraplegia (HSP), the axons of cortical motor neurons degenerate and cause a spastic movement disorder. HSP is linked to mutations in several loci known collectively as the spastic paraplegia genes (SPGs). We identified a heterozygous receptor accessory protein 1 (REEP1) exon 2 deletion in a patient suffering from the autosomal dominantly inherited HSP variant SPG31. We generated the corresponding mouse model to study the underlying cellular pathology. Mice with heterozygous deletion of exon 2 in Reep1 displayed a gait disorder closely resembling SPG31 in humans. Homozygous exon 2 deletion resulted in the complete loss of REEP1 and a more severe phenotype with earlier onset. At the molecular level, we demonstrated that REEP1 is a neuron-specific, membrane-binding, and membrane curvature-inducing protein that resides in the ER. We further show that Reep1 expression was prominent in cortical motor neurons. In REEP1-deficient mice, these neurons showed reduced complexity of the peripheral ER upon ultrastructural analysis. Our study connects proper neuronal ER architecture to long-term axon survival.
Collapse
|
38
|
Schüler S, Hauptmann J, Perner B, Kessels MM, Englert C, Qualmann B. Ciliated sensory hair cell formation and function require the F-BAR protein syndapin I and the WH2 domain-based actin nucleator Cobl. J Cell Sci 2013. [DOI: 10.1242/jcs.138917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
39
|
Schüler S, Hauptmann J, Perner B, Kessels MM, Englert C, Qualmann B. Ciliated sensory hair cell formation and function require the F-BAR protein syndapin I and the WH2 domain-based actin nucleator Cobl. J Cell Sci 2012. [PMID: 23203810 DOI: 10.1242/jcs.111674] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
During development, general body plan information must be translated into distinct morphologies of individual cells. Shaping cells is thought to involve cortical cytoskeletal components and Bin-Amphiphysin-Rvs167 (BAR) superfamily proteins. We therefore conducted comprehensive side-by-side loss-of-function studies of zebrafish orthologs of the F-BAR protein syndapin I and the actin nucleator Cobl. Zebrafish syndapin I associates with Cobl. The loss-of-function phenotypes of these proteins were remarkably similar and suggested a common function. Both cobl- and syndapin I-morphant fish showed severe swimming and balance-keeping defects, reflecting an impaired organization and function of the lateral line organ. Their lateral line organs lacked several neuromasts and showed an impaired functionality of the sensory hair cells within the neuromasts. Scanning electron microscopy revealed that sensory hair cells of both cobl- and syndapin I-morphant animals showed defects in the formation of both microtubule-dependent kinocilia and F-actin-rich stereocilia. Consistent with the kinocilia defects in sensory hair cells, body length was shortened and the development of body laterality, a process depending on motile cilia, was also impaired. Interestingly, Cobl and syndapin I both localized to the base of forming cilia. Rescue experiments demonstrated that proper formation of ciliated sensory hair cell rosettes relied on Cobl's syndapin I-binding Cobl homology domain, the actin-nucleating C-terminus of Cobl and the membrane curvature-inducing F-BAR domain of syndapin I. Our data thus suggest that the formation of distinct types of ciliary structures relies on membrane topology-modulating mechanisms that are based on F-BAR domain functions and on complex formation of syndapin I with the actin nucleator Cobl.
Collapse
Affiliation(s)
- Susann Schüler
- Institute of Biochemistry I, Jena University Hospital/Friedrich-Schiller-University Jena, 07743 Jena, Germany
| | | | | | | | | | | |
Collapse
|
40
|
Koch D, Westermann M, Kessels MM, Qualmann B. Ultrastructural freeze-fracture immunolabeling identifies plasma membrane-localized syndapin II as a crucial factor in shaping caveolae. Histochem Cell Biol 2012; 138:215-30. [DOI: 10.1007/s00418-012-0945-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2012] [Indexed: 10/28/2022]
|
41
|
Koch N, Dharmalingam E, Westermann M, Qualmann B, Thomas U, Kessels MM. Abp1 utilizes the Arp2/3 complex activator Scar/WAVE in bristle development. J Cell Sci 2012; 125:3578-89. [PMID: 22467854 DOI: 10.1242/jcs.101451] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many developmental processes rely on cortical actin dynamics; however, the mechanisms of its fine control at the cell cortex are still largely unknown. Our analyses demonstrate that the lipid- and F-actin-binding protein Abp1 is crucial for actin-driven bristle development in Drosophila melanogaster. Combined genetic, cell biological and biochemical analyses reveal that Abp1 triggers cortical Arp2/3-mediated actin nucleation by complex formation with Scar in bristle development. The role of the plasma-membrane-associated Abp1 subpool was highlighted by constitutively membrane-anchored Abp1. Such gain-of-function experiments led to a severe split-bristle phenotype, which was negatively correlated with bristle length. This phenotype was dependent on Scar but not on WASP and required the Scar-interacting SH3 domain of Abp1. Strikingly, knockout of abp1 led to defects in both microchaete and macrochaete bristle integrity. Importantly, Arp2- and Scar-deficient flies displayed similar bristle phenotypes. Microchaetes of flies deficient for Abp1, Arp2 and Scar functions had kinks, whereas those of wasp heterozygous flies did not. Electron microscopy analyses revealed that abp1 knockout, Arp2 RNAi and Scar RNAi all led to distorted macrochaetes with an excessive number of ridges. Interestingly, despite the physical association of Abp1 with Scar and its ability to use the Arp2/3 complex activator as an effector, abp1 knockout did not affect Scar stability. This is in contrast to classical Scar complex components, such as Kette or Sra-1. Our work reveals that Abp1 is an important, Scar-interacting factor controlling cortical Arp2/3-mediated actin nucleation and unravels a novel layer of complexity in the scrupulous control of cortical actin nucleation during sensory organ formation.
Collapse
Affiliation(s)
- Nicole Koch
- Institute for Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743 Jena, Germany
| | | | | | | | | | | |
Collapse
|
42
|
Koch D, Spiwoks-Becker I, Sabanov V, Sinning A, Dugladze T, Stellmacher A, Ahuja R, Grimm J, Schüler S, Müller A, Angenstein F, Ahmed T, Diesler A, Moser M, Tom Dieck S, Spessert R, Boeckers TM, Fässler R, Hübner CA, Balschun D, Gloveli T, Kessels MM, Qualmann B. Proper synaptic vesicle formation and neuronal network activity critically rely on syndapin I. EMBO J 2011; 30:4955-69. [PMID: 21926968 DOI: 10.1038/emboj.2011.339] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 08/23/2011] [Indexed: 02/03/2023] Open
Abstract
Synaptic transmission relies on effective and accurate compensatory endocytosis. F-BAR proteins may serve as membrane curvature sensors and/or inducers and thereby support membrane remodelling processes; yet, their in vivo functions urgently await disclosure. We demonstrate that the F-BAR protein syndapin I is crucial for proper brain function. Syndapin I knockout (KO) mice suffer from seizures, a phenotype consistent with excessive hippocampal network activity. Loss of syndapin I causes defects in presynaptic membrane trafficking processes, which are especially evident under high-capacity retrieval conditions, accumulation of endocytic intermediates, loss of synaptic vesicle (SV) size control, impaired activity-dependent SV retrieval and defective synaptic activity. Detailed molecular analyses demonstrate that syndapin I plays an important role in the recruitment of all dynamin isoforms, central players in vesicle fission reactions, to the membrane. Consistently, syndapin I KO mice share phenotypes with dynamin I KO mice, whereas their seizure phenotype is very reminiscent of fitful mice expressing a mutant dynamin. Thus, syndapin I acts as pivotal membrane anchoring factor for dynamins during regeneration of SVs.
Collapse
Affiliation(s)
- Dennis Koch
- Institute of Biochemistry I, Jena University Hospital-Friedrich Schiller University Jena, Jena, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
Against the odds of membrane resistance, members of the BIN/Amphiphysin/Rvs (BAR) domain superfamily shape membranes and their activity is indispensable for a plethora of life functions. While crystal structures of different BAR dimers advanced our understanding of membrane shaping by scaffolding and hydrophobic insertion mechanisms considerably, especially life-imaging techniques and loss-of-function studies of clathrin-mediated endocytosis with its gradually increasing curvature show that the initial idea that solely BAR domain curvatures determine their functions is oversimplified. Diagonal placing, lateral lipid-binding modes, additional lipid-binding modules, tilde shapes and formation of macromolecular lattices with different modes of organisation and arrangement increase versatility. A picture emerges, in which BAR domain proteins create macromolecular platforms, that recruit and connect different binding partners and ensure the connection and coordination of the different events during the endocytic process, such as membrane invagination, coat formation, actin nucleation, vesicle size control, fission, detachment and uncoating, in time and space, and may thereby offer mechanistic explanations for how coordination, directionality and effectiveness of a complex process with several steps and key players can be achieved.
Collapse
Affiliation(s)
- Britta Qualmann
- Institute for Biochemistry I, University Hospital Jena-Friedrich Schiller University Jena, Germany.
| | | | | |
Collapse
|
44
|
Kessels MM, Schwintzer L, Schlobinski D, Qualmann B. Controlling actin cytoskeletal organization and dynamics during neuronal morphogenesis. Eur J Cell Biol 2010; 90:926-33. [PMID: 20965607 DOI: 10.1016/j.ejcb.2010.08.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 08/27/2010] [Accepted: 08/27/2010] [Indexed: 11/26/2022] Open
Abstract
Coordinated functions of the actin cytoskeleton and microtubules, which need to be carefully controlled in time and space, are required for the drastic alterations of neuronal morphology during neuromorphogenesis and neuronal network formation. A key process in neuronal actin dynamics is filament formation by actin nucleators, such as the Arp2/3 complex, formins and the brain-enriched, novel WH2 domain-based nucleators Spire and cordon-bleu (Cobl). We here discuss in detail the currently available data on the roles of these actin nucleators during neuromorphogenesis and highlight how their required control at the plasma membrane may be brought about. The Arp2/3 complex was found to be especially important for proper growth cone translocation and axon development. The underlying molecular mechanisms for Arp2/3 complex activation at the neuronal plasma membrane include a recruitment and an activation of N-WASP by lipid- and F-actin-binding adaptor proteins, Cdc42 and phosphatidyl-inositol-(4,5)-bisphosphate (PIP(2)). Together, these components upstream of N-WASP and the Arp2/3 complex ensure fine-control of N-WASP-mediated Arp2/3 complex activation and control distinct functions during axon development. They are counteracted by Arp2/3 complex inhibitors, such as PICK, which likewise play an important role in neuromorphogenesis. In contrast to the crucial role of the Arp2/3 complex in proper axon development, dendrite formation and dendritic arborization was revealed to critically involve the newly identified actin nucleator Cobl. Cobl is a brain-enriched protein and uses three Wiskott-Aldrich syndrome protein homology 2 (WH2) domains for actin binding and for promoting the formation of non-bundled, unbranched filaments. Thus, cells use different actin nucleators to steer the complex remodeling processes underlying cell morphogenesis, the formation of cellular networks and the development of complex body plans.
Collapse
Affiliation(s)
- Michael Manfred Kessels
- Institute for Biochemistry I, University Hospital Jena - Friedrich-Schiller-University Jena, Nonnenplan 2, 07743 Jena, Germany.
| | | | | | | |
Collapse
|
45
|
Qualmann B, Kessels MM. New players in actin polymerization--WH2-domain-containing actin nucleators. Trends Cell Biol 2009; 19:276-85. [PMID: 19406642 DOI: 10.1016/j.tcb.2009.03.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 02/24/2009] [Accepted: 03/09/2009] [Indexed: 01/07/2023]
Abstract
Actin nucleators promote the polymerization of the different types of actin arrays formed in a variety of cellular processes, such as cell migration, cellular morphogenesis and membrane trafficking processes. Several novel nucleators have been discovered recently. They all contain Wiskott-Aldrich syndrome protein (WASP) homology 2 (WH2 or W) domains for actin nucleation but seem to employ different molecular mechanisms and serve distinct cellular functions. Here, we summarize what is currently known about the different molecular mechanisms that Spire, Cordon-Bleu and Leiomodin seem to use and, also, the bacterial counterparts that mimic them (VopF, VopL and TARP). Recent studies on these WH2 proteins offer unique insight into the biological problem of actin-filament formation and how cells use specialized molecular machines to bring about so many different cytoskeletal structures.
Collapse
Affiliation(s)
- Britta Qualmann
- Institute for Biochemistry I, Friedrich-Schiller-University Jena, Nonnenplan 2, Jena, Germany
| | | |
Collapse
|
46
|
Salvarezza SB, Deborde S, Schreiner R, Campagne F, Kessels MM, Qualmann B, Caceres A, Kreitzer G, Rodriguez-Boulan E. LIM kinase 1 and cofilin regulate actin filament population required for dynamin-dependent apical carrier fission from the trans-Golgi network. Mol Biol Cell 2008; 20:438-51. [PMID: 18987335 DOI: 10.1091/mbc.e08-08-0891] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The functions of the actin cytoskeleton in post-Golgi trafficking are still poorly understood. Here, we report the role of LIM Kinase 1 (LIMK1) and its substrate cofilin in the trafficking of apical and basolateral proteins in Madin-Darby canine kidney cells. Our data indicate that LIMK1 and cofilin organize a specialized population of actin filaments at the Golgi complex that is selectively required for the emergence of an apical cargo route to the plasma membrane (PM). Quantitative pulse-chase live imaging experiments showed that overexpression of kinase-dead LIMK1 (LIMK1-KD), or of LIMK1 small interfering RNA, or of an activated cofilin mutant (cofilin S3A), selectively slowed down the exit from the trans-Golgi network (TGN) of the apical PM marker p75-green fluorescent protein (GFP) but did not interfere with the apical PM marker glycosyl phosphatidylinositol-YFP or the basolateral PM marker neural cell adhesion molecule-GFP. High-resolution live imaging experiments of carrier formation and release by the TGN and analysis of peri-Golgi actin dynamics using photoactivatable GFP suggest a scenario in which TGN-localized LIMK1-cofilin regulate a population of actin filaments required for dynamin-syndapin-cortactin-dependent generation and/or fission of precursors to p75 transporters.
Collapse
Affiliation(s)
- Susana B Salvarezza
- Margaret Dyson Vision Research Institute and Department of Cell and Developmental Biology, HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Medical College of Cornell University, New York, NY 10065, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Onabajo OO, Seeley MK, Kale A, Qualmann B, Kessels M, Han J, Tan TH, Song W. Actin-binding protein 1 regulates B cell receptor-mediated antigen processing and presentation in response to B cell receptor activation. J Immunol 2008; 180:6685-95. [PMID: 18453588 DOI: 10.4049/jimmunol.180.10.6685] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The BCR serves as both signal transducer and Ag transporter. Binding of Ags to the BCR induces signaling cascades and Ag processing and presentation, two essential cellular events for B cell activation. BCR-initiated signaling increases BCR-mediated Ag-processing efficiency by increasing the rate and specificity of Ag transport. Previous studies showed a critical role for the actin cytoskeleton in these two processes. In this study, we found that actin-binding protein 1 (Abp1/HIP-55/SH3P7) functioned as an actin-binding adaptor protein, coupling BCR signaling and Ag-processing pathways with the actin cytoskeleton. Gene knockout of Abp1 and overexpression of the Src homology 3 domain of Abp1 inhibited BCR-mediated Ag internalization, consequently reducing the rate of Ag transport to processing compartments and the efficiency of BCR-mediated Ag processing and presentation. BCR activation induced tyrosine phosphorylation of Abp1 and translocation of both Abp1 and dynamin 2 from the cytoplasm to plasma membrane, where they colocalized with the BCR and cortical F-actin. Mutations of the two tyrosine phosphorylation sites of Abp1 and depolymerization of the actin cytoskeleton interfered with BCR-induced Abp1 recruitment to the plasma membrane. The inhibitory effect of a dynamin proline-rich domain deletion mutant on the recruitment of Abp1 to the plasma membrane, coimmunoprecipitation of dynamin with Abp1, and coprecipitation of Abp1 with GST fusion of the dyanmin proline-rich domain demonstrate the interaction of Abp1 with dynamin 2. These results demonstrate that the BCR regulates the function of Abp1 by inducing Abp1 phosphorylation and actin cytoskeleton rearrangement, and that Abp1 facilitates BCR-mediated Ag processing by simultaneously interacting with dynamin and the actin cytoskeleton.
Collapse
Affiliation(s)
- Olusegun O Onabajo
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | | | | | | | | | | | | | | |
Collapse
|
48
|
|
49
|
Ahuja R, Pinyol R, Reichenbach N, Custer L, Klingensmith J, Kessels MM, Qualmann B. Cordon-bleu is an actin nucleation factor and controls neuronal morphology. Cell 2008; 131:337-50. [PMID: 17956734 DOI: 10.1016/j.cell.2007.08.030] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 05/11/2007] [Accepted: 08/10/2007] [Indexed: 11/25/2022]
Abstract
Despite the wealth of different actin structures formed, only two actin nucleation factors are well established in vertebrates: the Arp2/3 complex and formins. Here, we describe a further nucleator, cordon-bleu (Cobl). Cobl is a brain-enriched protein using three Wiskott-Aldrich syndrome protein homology 2 (WH2) domains for actin binding. Cobl promotes nonbundled, unbranched filaments. Filament formation relies on barbed-end growth and requires all three Cobl WH2 domains and the extended linker L2. We suggest that the nucleation power of Cobl is based on the assembly of three actin monomers in cross-filament orientation. Cobl localizes to sites of high actin dynamics and modulates cell morphology. In neurons, induction of both neurites and neurite branching is dramatically increased by Cobl expression-effects that critically depend on Cobl's actin nucleation ability. Correspondingly, Cobl depletion results in decreased dendritic arborization. Thus, Cobl is an actin nucleator controlling neuronal morphology and development.
Collapse
Affiliation(s)
- Rashmi Ahuja
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | | | | | | | | | | | | |
Collapse
|
50
|
Pinyol R, Haeckel A, Ritter A, Qualmann B, Kessels MM. Regulation of N-WASP and the Arp2/3 complex by Abp1 controls neuronal morphology. PLoS One 2007; 2:e400. [PMID: 17476322 PMCID: PMC1852583 DOI: 10.1371/journal.pone.0000400] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Accepted: 04/04/2007] [Indexed: 11/19/2022] Open
Abstract
Polymerization and organization of actin filaments into complex superstructures is indispensable for structure and function of neuronal networks. We here report that knock down of the F-actin-binding protein Abp1, which is important for endocytosis and synaptic organization, results in changes in axon development virtually identical to Arp2/3 complex inhibition, i.e., a selective increase of axon length. Our in vitro and in vivo experiments demonstrate that Abp1 interacts directly with N-WASP, an activator of the Arp2/3 complex, and releases the autoinhibition of N-WASP in cooperation with Cdc42 and thereby promotes N-WASP-triggered Arp2/3 complex-mediated actin polymerization. In line with our mechanistical studies and the colocalization of Abp1, N-WASP and Arp2/3 at sites of actin polymerization in neurons, we reveal an essential role of Abp1 and its cooperativity with Cdc42 in N-WASP-induced rearrangements of the neuronal cytoskeleton. We furthermore show that introduction of N-WASP mutants lacking the ability to bind Abp1 or Cdc42, Arp2/3 complex inhibition, Abp1 knock down, N-WASP knock down and Arp3 knock down, all cause identical neuromorphological phenotypes. Our data thus strongly suggest that these proteins and their complex formation are important for cytoskeletal processes underlying neuronal network formation.
Collapse
Affiliation(s)
- Roser Pinyol
- Research Group Membrane Trafficking and Cytoskeleton, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Research Group Cell Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Akvile Haeckel
- Research Group Membrane Trafficking and Cytoskeleton, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Research Group Cell Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Anett Ritter
- Research Group Membrane Trafficking and Cytoskeleton, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Britta Qualmann
- Research Group Cell Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Michael Manfred Kessels
- Research Group Membrane Trafficking and Cytoskeleton, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|