1
|
Xu L, Zheng S, Chen L, Yang L, Zhang S, Liu B, Shen K, Feng Q, Zhou Q, Yao M. N4-acetylcytidine acetylation of neurexin 2 in the spinal dorsal horn regulates hypersensitivity in a rat model of cancer-induced bone pain. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102200. [PMID: 38831898 PMCID: PMC11145350 DOI: 10.1016/j.omtn.2024.102200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/21/2024] [Indexed: 06/05/2024]
Abstract
Cancer-induced bone pain (CIBP) significantly impacts the quality of life and survival of patients with advanced cancer. Despite the established role of neurexins in synaptic structure and function, their involvement in sensory processing during injury has not been extensively studied. In this study using a rat model of CIBP, we observed increased neurexin 2 expression in spinal cord neurons. Knockdown of neurexin 2 in the spinal cord reversed CIBP-related behaviors, sensitization of spinal c-Fos neurons, and pain-related negative emotional behaviors. Additionally, increased acetylation of neurexin 2 mRNA was identified in the spinal dorsal horn of CIBP rats. Decreasing the expression of N-acetyltransferase 10 (NAT10) reduced neurexin 2 mRNA acetylation and neurexin 2 expression. In PC12 cells, we confirmed that neurexin 2 mRNA acetylation enhanced its stability, and neurexin 2 expression was regulated by NAT10. Finally, we discovered that the NAT10/ac4C-neurexin 2 axis modulated neuronal synaptogenesis. This study demonstrated that the NAT10/ac4C-mediated posttranscriptional modulation of neurexin 2 expression led to the remodeling of spinal synapses and the development of conscious hypersensitivity in CIBP rats. Therefore, targeting the epigenetic modification of neurexin 2 mRNA ac4C may offer a new therapeutic approach for the treatment of nociceptive hypersensitivity in CIBP.
Collapse
Affiliation(s)
- Longsheng Xu
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Shang Zheng
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Liping Chen
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Lei Yang
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Shuyao Zhang
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Beibei Liu
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Kangli Shen
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Qinli Feng
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Qinghe Zhou
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| | - Ming Yao
- Department of Anesthesia and Pain Medicine, Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
| |
Collapse
|
2
|
Janz P, Bainier M, Marashli S, Schoenenberger P, Valencia M, Redondo RL. Neurexin1α knockout rats display oscillatory abnormalities and sensory processing deficits back-translating key endophenotypes of psychiatric disorders. Transl Psychiatry 2022; 12:455. [PMID: 36307390 PMCID: PMC9616904 DOI: 10.1038/s41398-022-02224-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
Neurexins are presynaptic transmembrane proteins crucial for synapse development and organization. Deletion and missense mutations in all three Neurexin genes have been identified in psychiatric disorders, with mutations in the NRXN1 gene most strongly linked to schizophrenia (SZ) and autism spectrum disorder (ASD). While the consequences of NRXN1 deletion have been extensively studied on the synaptic and behavioral levels, circuit endophenotypes that translate to the human condition have not been characterized yet. Therefore, we investigated the electrophysiology of cortico-striatal-thalamic circuits in Nrxn1α-/- rats and wildtype littermates focusing on a set of translational readouts, including spontaneous oscillatory activity, auditory-evoked oscillations and potentials, as well as mismatch negativity-like (MMN) responses and responses to social stimuli. On the behavioral level Nrxn1α-/- rats showed locomotor hyperactivity. In vivo freely moving electrophysiology revealed pronounced increases of spontaneous oscillatory power within the gamma band in all studied brain areas and elevation of gamma coherence in cortico-striatal and thalamocortical circuits of Nrxn1α-/- rats. In contrast, auditory-evoked oscillations driven by chirp-modulated tones showed reduced power in cortical areas confined to slower oscillations. Finally, Nrxn1α-/- rats exhibited altered auditory evoked-potentials and profound deficits in MMN-like responses, explained by reduced prediction error. Despite deficits for auditory stimuli, responses to social stimuli appeared intact. A central hypothesis for psychiatric and neurodevelopmental disorders is that a disbalance of excitation-to-inhibition is underlying oscillatory and sensory deficits. In a first attempt to explore the impact of inhibitory circuit modulation, we assessed the effects of enhancing tonic inhibition via δ-containing GABAA receptors (using Gaboxadol) on endophenotypes possibly associated with network hyperexcitability. Pharmacological experiments applying Gaboxadol showed genotype-specific differences, but failed to normalize oscillatory or sensory processing abnormalities. In conclusion, our study revealed endophenotypes in Nrxn1α-/- rats that could be used as translational biomarkers for drug development in psychiatric disorders.
Collapse
Affiliation(s)
- Philipp Janz
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070, Basel, Switzerland.
| | - Marie Bainier
- grid.417570.00000 0004 0374 1269Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Samuel Marashli
- grid.417570.00000 0004 0374 1269Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Philipp Schoenenberger
- grid.417570.00000 0004 0374 1269Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Miguel Valencia
- grid.5924.a0000000419370271Universidad de Navarra, CIMA, Program of Neuroscience, 31080 Pamplona, Spain ,grid.508840.10000 0004 7662 6114IdiSNA, Navarra Institute for Health Research, 31080 Pamplona, Spain ,grid.5924.a0000000419370271Institute of Data Science and Artificial Intelligence, Universidad de Navarra, 31080 Pamplona, Spain
| | - Roger L. Redondo
- grid.417570.00000 0004 0374 1269Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070 Basel, Switzerland
| |
Collapse
|
3
|
Wang D, Zhang P, Liu Z, Xing Y, Xiao Y. NXPH4 Promotes Gemcitabine Resistance in Bladder Cancer by Enhancing Reactive Oxygen Species and Glycolysis Activation through Modulating NDUFA4L2. Cancers (Basel) 2022; 14:cancers14153782. [PMID: 35954445 PMCID: PMC9367313 DOI: 10.3390/cancers14153782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/22/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022] Open
Abstract
Bladder cancer is one of the most prevalent kinds of cancer worldwide, and resistance to gemcitabine is a major problem for patients. The pathogenesis of bladder cancer and mechanism of resistance to chemotherapy remain to be explored. Through bioinformatics analysis, we first found that NXPH4 was independently related to the prognosis of patients with bladder cancer. Through wound healing assays, transwell invasion assays, and plate clone formation assays, we found that NXPH4 promoted the proliferation, migration, and invasion of bladder cancer cells. The induced gemcitabine resistance cell line also showed a higher expression of NXPH4. A glycolytic activity assay demonstrated that the expression of NXPH4 was positively related to glycolysis. A higher level of reactive oxygen species caused by enhanced levels of NXPH4 was found in gemcitabine-resistant cell lines. NDUFA4L2, glycolysis, and reactive oxygen species were shown to be essential for NXPH4-regulated functions through rescue assays in cell lines. The roles of NXPH4-regulated glycolysis, gemcitabine resistance, and NDUFA4L2 were validated in vivo as well. Our results imply that NXPH4 contributes to the proliferation, migration, and invasion of bladder cancer by maintaining the stability of NDUFA4L2 and consequently activating reactive oxygen species and glycolysis.
Collapse
Affiliation(s)
- Decai Wang
- Department of Urology Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; (D.W.); (P.Z.)
| | - Pu Zhang
- Department of Urology Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; (D.W.); (P.Z.)
| | - Zijian Liu
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China;
| | - Yifei Xing
- Department of Urology Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; (D.W.); (P.Z.)
- Correspondence: (Y.X.); (Y.X.)
| | - Yajun Xiao
- Department of Urology Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China; (D.W.); (P.Z.)
- Correspondence: (Y.X.); (Y.X.)
| |
Collapse
|
4
|
Serova OV, Gantsova EA, Deyev IE, Petrenko AG. Tissue-Specific Expression of Neurexin-1α Isoforms in Rat Organs. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2022. [DOI: 10.1134/s1068162022020194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract—
Neurexins are a family of synaptic adhesion proteins that play a key role in synapse formation and maintenance. Neurexins undergo extensive alternative splicing at six sites (SS1–SS6) resulting in expression of multiplicity of different isoforms. Alternative splicing regulates the functional activity of neurexins in different types of tissues and cells and presumably plays a key role in determining the specificity of the interaction of various neurons. In this study, we have investigated the pattern of tissue expression of neurexin-1α mRNA isoforms including an insert in the recently discovered splice site SS6 using TaqMan Real-Time PCR in different organs of Wistar rats. The isoform containing the insert in the SS6 site was found only in neural tissues suggesting its potential functional importance. Position of the SS6 insert in the hinge region between the LNS5 and LNS6 domains increases variability of possible conformations of the molecule which may represent an additional mechanism for regulating functional activity of the neurexin-1α in the brain.
Collapse
|
5
|
Interplay between hevin, SPARC, and MDGAs: Modulators of neurexin-neuroligin transsynaptic bridges. Structure 2021; 29:664-678.e6. [PMID: 33535026 DOI: 10.1016/j.str.2021.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/20/2020] [Accepted: 01/08/2021] [Indexed: 12/18/2022]
Abstract
Hevin is secreted by astrocytes and its synaptogenic effects are antagonized by the related protein, SPARC. Hevin stabilizes neurexin-neuroligin transsynaptic bridges in vivo. A third protein, membrane-tethered MDGA, blocks these bridges. Here, we reveal the molecular underpinnings of a regulatory network formed by this trio of proteins. The hevin FS-EC structure differs from SPARC, in that the EC domain appears rearranged around a conserved core. The FS domain is structurally conserved and it houses nanomolar affinity binding sites for neurexin and neuroligin. SPARC also binds neurexin and neuroligin, competing with hevin, so its antagonist action is rooted in its shortened N-terminal region. Strikingly, the hevin FS domain competes with MDGA for an overlapping binding site on neuroligin, while the hevin EC domain binds the extracellular matrix protein collagen (like SPARC), so that this trio of proteins can regulate neurexin-neuroligin transsynaptic bridges and also extracellular matrix interactions, impacting synapse formation and ultimately neural circuits.
Collapse
|
6
|
Kim HY, Um JW, Ko J. Proper synaptic adhesion signaling in the control of neural circuit architecture and brain function. Prog Neurobiol 2021; 200:101983. [PMID: 33422662 DOI: 10.1016/j.pneurobio.2020.101983] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/23/2020] [Accepted: 12/22/2020] [Indexed: 12/17/2022]
Abstract
Trans-synaptic cell-adhesion molecules are critical for governing various stages of synapse development and specifying neural circuit properties via the formation of multifarious signaling pathways. Recent studies have pinpointed the putative roles of trans-synaptic cell-adhesion molecules in mediating various cognitive functions. Here, we review the literature on the roles of a diverse group of central synaptic organizers, including neurexins (Nrxns), leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs), and their associated binding proteins, in regulating properties of specific type of synapses and neural circuits. In addition, we highlight the findings that aberrant synaptic adhesion signaling leads to alterations in the structures, transmission, and plasticity of specific synapses across diverse brain areas. These results seem to suggest that proper trans-synaptic signaling pathways by Nrxns, LAR-RPTPs, and their interacting network is likely to constitute central molecular complexes that form the basis for cognitive functions, and that these complexes are heterogeneously and complexly disrupted in many neuropsychiatric and neurodevelopmental disorders.
Collapse
Affiliation(s)
- Hee Young Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea; Core Protein Resources Center, DGIST, Daegu, 42988, South Korea.
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea.
| |
Collapse
|
7
|
Ishizuka K, Yoshida T, Kawabata T, Imai A, Mori H, Kimura H, Inada T, Okahisa Y, Egawa J, Usami M, Kushima I, Morikawa M, Okada T, Ikeda M, Branko A, Mori D, Someya T, Iwata N, Ozaki N. Functional characterization of rare NRXN1 variants identified in autism spectrum disorders and schizophrenia. J Neurodev Disord 2020; 12:25. [PMID: 32942984 PMCID: PMC7496212 DOI: 10.1186/s11689-020-09325-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 07/28/2020] [Indexed: 11/10/2022] Open
Abstract
Background Rare genetic variants contribute to the etiology of both autism spectrum disorder (ASD) and schizophrenia (SCZ). Most genetic studies limit their focus to likely gene-disrupting mutations because they are relatively easier to interpret their effects on the gene product. Interpretation of missense variants is also informative to some pathophysiological mechanisms of these neurodevelopmental disorders; however, their contribution has not been elucidated because of relatively small effects. Therefore, we characterized missense variants detected in NRXN1, a well-known neurodevelopmental disease-causing gene, from individuals with ASD and SCZ. Methods To discover rare variants with large effect size and to evaluate their role in the shared etiopathophysiology of ASD and SCZ, we sequenced NRXN1 coding exons with a sample comprising 562 Japanese ASD and SCZ patients, followed by a genetic association analysis in 4273 unrelated individuals. Impact of each missense variant detected here on cell surface expression, interaction with NLGN1, and synaptogenic activity was analyzed using an in vitro functional assay and in silico three-dimensional (3D) structural modeling. Results Through mutation screening, we regarded three ultra-rare missense variants (T737M, D772G, and R856W), all of which affected the LNS4 domain of NRXN1α isoform, as disease-associated variants. Diagnosis of individuals with T737M, D772G, and R856W was 1ASD and 1SCZ, 1ASD, and 1SCZ, respectively. We observed the following phenotypic and functional burden caused by each variant. (i) D772G and R856W carriers had more serious social disabilities than T737M carriers. (ii) In vitro assay showed reduced cell surface expression of NRXN1α by D772G and R856W mutations. In vitro functional analysis showed decreased NRXN1α-NLGN1 interaction of T737M and D772G mutants. (iii) In silico 3D structural modeling indicated that T737M and D772G mutations could destabilize the rod-shaped structure of LNS2-LNS5 domains, and D772G and R856W could disturb N-glycan conformations for the transport signal. Conclusions The combined data suggest that missense variants in NRXN1 could be associated with phenotypes of neurodevelopmental disorders beyond the diagnosis of ASD and/or SCZ.
Collapse
Affiliation(s)
- Kanako Ishizuka
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 9300194, Japan
| | - Takeshi Kawabata
- Institute for Protein Research, Osaka University, Osaka, 5650871, Japan
| | - Ayako Imai
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 9300194, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 9300194, Japan
| | - Hiroki Kimura
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Toshiya Inada
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Yuko Okahisa
- Department of Neuropsychiatry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 7008558, Japan
| | - Jun Egawa
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 9518510, Japan
| | - Masahide Usami
- Department of Child and Adolescent Psychiatry, Kohnodai Hospital, National Center for Global Health and Medicine, Ichikawa, Chiba, 2728516, Japan
| | - Itaru Kushima
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Mako Morikawa
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Takashi Okada
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Masashi Ikeda
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 4701192, Japan
| | - Aleksic Branko
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| | - Daisuke Mori
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan. .,Brain and Mind Research Center, Nagoya University, Nagoya, Aichi, 4668550, Japan.
| | - Toshiyuki Someya
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 9518510, Japan
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 4701192, Japan
| | - Norio Ozaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 4668550, Japan
| |
Collapse
|
8
|
LoTToR: An Algorithm for Missing-Wedge Correction of the Low-Tilt Tomographic 3D Reconstruction of a Single-Molecule Structure. Sci Rep 2020; 10:10489. [PMID: 32591588 PMCID: PMC7320192 DOI: 10.1038/s41598-020-66793-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 05/27/2020] [Indexed: 01/01/2023] Open
Abstract
A single-molecule three-dimensional (3D) structure is essential for understanding the thermal vibrations and dynamics as well as the conformational changes during the chemical reaction of macromolecules. Individual-particle electron tomography (IPET) is an approach for obtaining a snap-shot 3D structure of an individual macromolecule particle by aligning the tilt series of electron tomographic (ET) images of a targeted particle through a focused iterative 3D reconstruction method. The method can reduce the influence on the 3D reconstruction from large-scale image distortion and deformation. Due to the mechanical tilt limitation, 3D reconstruction often contains missing-wedge artifacts, presented as elongation and an anisotropic resolution. Here, we report a post-processing method to correct the missing-wedge artifact. This low-tilt tomographic reconstruction (LoTToR) method contains a model-free iteration process under a set of constraints in real and reciprocal spaces. A proof of concept is conducted by using the LoTToR on a phantom, i.e., a simulated 3D reconstruction from a low-tilt series of images, including that within a tilt range of ±15°. The method is validated by using both negative-staining (NS) and cryo-electron tomography (cryo-ET) experimental data. A significantly reduced missing-wedge artifact verifies the capability of LoTToR, suggesting a new tool to support the future study of macromolecular dynamics, fluctuation and chemical activity from the viewpoint of single-molecule 3D structure determination.
Collapse
|
9
|
Lei D, Liu J, Liu H, Cleveland TE, Marino JP, Lei M, Ren G. Single-Molecule 3D Images of "Hole-Hole" IgG1 Homodimers by Individual-Particle Electron Tomography. Sci Rep 2019; 9:8864. [PMID: 31221961 PMCID: PMC6586654 DOI: 10.1038/s41598-019-44978-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/30/2019] [Indexed: 12/20/2022] Open
Abstract
The engineering of immunoglobulin-G molecules (IgGs) is of wide interest for improving therapeutics, for example by modulating the activity or multiplexing the specificity of IgGs to recognize more than one antigen. Optimization of engineered IgG requires knowledge of three-dimensional (3D) structure of synthetic IgG. However, due to flexible nature of the molecules, their structural characterization is challenging. Here, we use our reported individual-particle electron tomography (IPET) method with optimized negative-staining (OpNS) for direct 3D reconstruction of individual IgG hole-hole homodimer molecules. The hole-hole homodimer is an undesired variant generated during the production of a bispecific antibody using the knob-into-hole heterodimer technology. A total of 64 IPET 3D density maps at ~15 Å resolutions were reconstructed from 64 individual molecules, revealing 64 unique conformations. In addition to the known Y-shaped conformation, we also observed an unusual X-shaped conformation. The 3D structure of the X-shaped conformation contributes to our understanding of the structural details of the interaction between two heavy chains in the Fc domain. The IPET approach, as an orthogonal technique to characterize the 3D structure of therapeutic antibodies, provides insight into the 3D structural variety and dynamics of heterogeneous IgG molecules.
Collapse
Affiliation(s)
- Dongsheng Lei
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Hongbin Liu
- Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA, 94080, USA
| | - Thomas E Cleveland
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology and the University of Maryland, Rockville, MD, 20850, USA
| | - John P Marino
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology and the University of Maryland, Rockville, MD, 20850, USA
| | - Ming Lei
- Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA, 94080, USA.
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| |
Collapse
|
10
|
Zambonino M, Pereira P. The structure of Neurexin 1α (n1α) and its role as synaptic organizer. BIONATURA 2019. [DOI: 10.21931/rb/2019.04.02.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
α - and b-neurexins (NRXNs) are transmembrane adhesion protein complexes localized in presynaptic membranes into neurons and interact with the postsynaptic neuroligins (NLGNs). Our findings indicate that the neurexin 1α (n1α) is a synaptic organizer that directs postsynaptic development in neurons, evidenced in GABAergic neurons and trials with Knock-out Mice. Also, the interactions between hypervariable surfaces of n1α and ligands (neurexophilin, a-dystroglycan, and GABAA) promotes a proper protein-binding recognition, and consequently, a better synaptic adhesion.
There is a direct relationship between mental disorders and the n1α assemblage because NRXN1 gene encodes for n1α proteins which are involved in the transmission of information into the brain. For this reason, damage in this complex-protein or some neurexin gene variations causes pathological abnormalities and neuropsychiatric diseases such as schizophrenia, autism spectrum disorders, and intellectual disabilities.
Collapse
Affiliation(s)
- Marjorie Zambonino
- Universidad de Investigación de Tecnología Experimental Yachay Tech 1,2School of Biological and Applied - Biomedical Engineering Department
| | - Pamela Pereira
- Universidad de Investigación de Tecnología Experimental Yachay Tech 1,2School of Biological and Applied - Biomedical Engineering Department
| |
Collapse
|
11
|
Neurexins - versatile molecular platforms in the synaptic cleft. Curr Opin Struct Biol 2019; 54:112-121. [PMID: 30831539 DOI: 10.1016/j.sbi.2019.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 01/05/2023]
Abstract
Neurexins constitute a large family of synaptic organizers. Their extracellular domains protrude into the synaptic cleft where they can form transsynaptic bridges with different partners. A unique constellation of structural elements within their ectodomains enables neurexins to create molecular platforms within the synaptic cleft that permit a large portfolio of partners to be recruited, assembled and their interactions to be dynamically regulated. Neurexins and their partners are implicated in neuropsychiatric diseases including autism spectrum disorder and schizophrenia. Detailed understanding of the mechanisms that underlie neurexin interactions may in future guide the design of tools to manipulate synaptic connections and their function, in particular those involved in the pathogenesis of neuropsychiatric disease.
Collapse
|