1
|
Campelo F, Lillo JV, von Blume J. Protein condensates in the the secretory pathway: Unraveling biophysical interactions and function. Biophys J 2024; 123:1531-1541. [PMID: 38698644 DOI: 10.1016/j.bpj.2024.04.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/23/2024] [Accepted: 04/30/2024] [Indexed: 05/05/2024] Open
Abstract
The emergence of phase separation phenomena among macromolecules has identified biomolecular condensates as fundamental cellular organizers. These condensates concentrate specific components and accelerate biochemical reactions without relying on membrane boundaries. Although extensive studies have revealed a large variety of nuclear and cytosolic membraneless organelles, we are witnessing a surge in the exploration of protein condensates associated with the membranes of the secretory pathway, such as the endoplasmic reticulum and the Golgi apparatus. This review focuses on protein condensates in the secretory pathway and discusses their impact on the organization and functions of this cellular process. Moreover, we explore the modes of condensate-membrane association and the biophysical and cellular consequences of protein condensate interactions with secretory pathway membranes.
Collapse
Affiliation(s)
- Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain.
| | - Javier Vera Lillo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Julia von Blume
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut.
| |
Collapse
|
2
|
Weakly HMJ, Keller SL. Coupling liquid phases in 3D condensates and 2D membranes: Successes, challenges, and tools. Biophys J 2024; 123:1329-1341. [PMID: 38160256 PMCID: PMC11163299 DOI: 10.1016/j.bpj.2023.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/05/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024] Open
Abstract
This review describes the major experimental challenges researchers meet when attempting to couple phase separation between membranes and condensates. Although it is well known that phase separation in a 2D membrane could affect molecules capable of forming a 3D condensate (and vice versa), few researchers have quantified the effects to date. The scarcity of these measurements is not due to a lack of intense interest or effort in the field. Rather, it reflects significant experimental challenges in manipulating coupled membranes and condensates to yield quantitative values. These challenges transcend many molecular details, which means they impact a wide range of systems. This review highlights recent exciting successes in the field, and it lays out a comprehensive list of tools that address potential pitfalls for researchers who are considering coupling membranes with condensates.
Collapse
Affiliation(s)
- Heidi M J Weakly
- Department of Chemistry, University of Washington - Seattle, Seattle, Washington
| | - Sarah L Keller
- Department of Chemistry, University of Washington - Seattle, Seattle, Washington.
| |
Collapse
|
3
|
Beiter J, Voth GA. Making the cut: Multiscale simulation of membrane remodeling. Curr Opin Struct Biol 2024; 87:102831. [PMID: 38740001 DOI: 10.1016/j.sbi.2024.102831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/17/2024] [Accepted: 04/22/2024] [Indexed: 05/16/2024]
Abstract
Biological membranes are dynamic heterogeneous materials, and their shape and organization are tightly coupled to the properties of the proteins in and around them. However, the length scales of lipid and protein dynamics are far below the size of membrane-bound organelles, much less an entire cell. Therefore, multiscale modeling approaches are often necessary to build a comprehensive picture of the interplay of these factors, and have provided critical insights into our understanding of membrane dynamics. Here, we review computational methods for studying membrane remodeling, as well as passive and active examples of protein-driven membrane remodeling. As the field advances towards the modeling of key aspects of organelles and whole cells - an increasingly accessible regime of study - we summarize here recent successes and offer comments on future trends.
Collapse
Affiliation(s)
- Jeriann Beiter
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA.
| |
Collapse
|
4
|
Kawaguchi K, Fujita N. Shaping transverse-tubules: central mechanisms that play a role in the cytosol zoning for muscle contraction. J Biochem 2024; 175:125-131. [PMID: 37848047 PMCID: PMC10873525 DOI: 10.1093/jb/mvad083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/19/2023] Open
Abstract
A transverse-tubule (T-tubule) is an invagination of the plasma membrane penetrating deep into muscle cells. An extensive membrane network of T-tubules is crucial for rapid and synchronized signal transmission from the cell surface to the entire sarcoplasmic reticulum for Ca2+ release, leading to muscle contraction. T-tubules are also indispensable for the formation and positioning of other muscle organelles. Their structure and physiological roles are relatively well established; however, the mechanisms shaping T-tubules require further elucidation. Centronuclear myopathy (CNM), an inherited muscular disorder, accompanies structural defects in T-tubules. Membrane traffic-related genes, including MTM1 (Myotubularin 1), DNM2 (Dynamin 2), and BIN1 (Bridging Integrator-1), were identified as causative genes of CNM. In addition, causative genes for other muscle diseases are also reported to be involved in the formation and maintenance of T-tubules. This review summarizes current knowledge on the mechanisms of how T-tubule formation and maintenance is regulated.
Collapse
Affiliation(s)
- Kohei Kawaguchi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259 S2-11 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Naonobu Fujita
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259 S2-11 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, 4259 S2-11 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| |
Collapse
|
5
|
Beck M, Covino R, Hänelt I, Müller-McNicoll M. Understanding the cell: Future views of structural biology. Cell 2024; 187:545-562. [PMID: 38306981 DOI: 10.1016/j.cell.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 02/04/2024]
Abstract
Determining the structure and mechanisms of all individual functional modules of cells at high molecular detail has often been seen as equal to understanding how cells work. Recent technical advances have led to a flush of high-resolution structures of various macromolecular machines, but despite this wealth of detailed information, our understanding of cellular function remains incomplete. Here, we discuss present-day limitations of structural biology and highlight novel technologies that may enable us to analyze molecular functions directly inside cells. We predict that the progression toward structural cell biology will involve a shift toward conceptualizing a 4D virtual reality of cells using digital twins. These will capture cellular segments in a highly enriched molecular detail, include dynamic changes, and facilitate simulations of molecular processes, leading to novel and experimentally testable predictions. Transferring biological questions into algorithms that learn from the existing wealth of data and explore novel solutions may ultimately unveil how cells work.
Collapse
Affiliation(s)
- Martin Beck
- Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; Goethe University Frankfurt, Frankfurt, Germany.
| | - Roberto Covino
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, 60438 Frankfurt am Main, Germany.
| | - Inga Hänelt
- Goethe University Frankfurt, Frankfurt, Germany.
| | | |
Collapse
|
6
|
Sigrist SJ, Haucke V. Orchestrating vesicular and nonvesicular membrane dynamics by intrinsically disordered proteins. EMBO Rep 2023; 24:e57758. [PMID: 37680133 PMCID: PMC10626433 DOI: 10.15252/embr.202357758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
Compartmentalization by membranes is a common feature of eukaryotic cells and serves to spatiotemporally confine biochemical reactions to control physiology. Membrane-bound organelles such as the endoplasmic reticulum (ER), the Golgi complex, endosomes and lysosomes, and the plasma membrane, continuously exchange material via vesicular carriers. In addition to vesicular trafficking entailing budding, fission, and fusion processes, organelles can form membrane contact sites (MCSs) that enable the nonvesicular exchange of lipids, ions, and metabolites, or the secretion of neurotransmitters via subsequent membrane fusion. Recent data suggest that biomolecule and information transfer via vesicular carriers and via MCSs share common organizational principles and are often mediated by proteins with intrinsically disordered regions (IDRs). Intrinsically disordered proteins (IDPs) can assemble via low-affinity, multivalent interactions to facilitate membrane tethering, deformation, fission, or fusion. Here, we review our current understanding of how IDPs drive the formation of multivalent protein assemblies and protein condensates to orchestrate vesicular and nonvesicular transport with a special focus on presynaptic neurotransmission. We further discuss how dysfunction of IDPs causes disease and outline perspectives for future research.
Collapse
Affiliation(s)
- Stephan J Sigrist
- Department of Biology, Chemistry, PharmacyFreie Universität BerlinBerlinGermany
| | - Volker Haucke
- Department of Biology, Chemistry, PharmacyFreie Universität BerlinBerlinGermany
- Department of Molecular Pharmacology and Cell BiologyLeibniz Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| |
Collapse
|
7
|
Sanfeliu-Cerdán N, Català-Castro F, Mateos B, Garcia-Cabau C, Ribera M, Ruider I, Porta-de-la-Riva M, Canals-Calderón A, Wieser S, Salvatella X, Krieg M. A MEC-2/stomatin condensate liquid-to-solid phase transition controls neuronal mechanotransduction during touch sensing. Nat Cell Biol 2023; 25:1590-1599. [PMID: 37857834 PMCID: PMC10635833 DOI: 10.1038/s41556-023-01247-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/01/2023] [Indexed: 10/21/2023]
Abstract
A growing body of work suggests that the material properties of biomolecular condensates ensuing from liquid-liquid phase separation change with time. How this aging process is controlled and whether the condensates with distinct material properties can have different biological functions is currently unknown. Using Caenorhabditis elegans as a model, we show that MEC-2/stomatin undergoes a rigidity phase transition from fluid-like to solid-like condensates that facilitate transport and mechanotransduction, respectively. This switch is triggered by the interaction between the SH3 domain of UNC-89 (titin/obscurin) and MEC-2. We suggest that this rigidity phase transition has a physiological role in frequency-dependent force transmission in mechanosensitive neurons during body wall touch. Our data demonstrate a function for the liquid and solid phases of MEC-2/stomatin condensates in facilitating transport or mechanotransduction, and a previously unidentified role for titin homologues in neurons.
Collapse
Affiliation(s)
- Neus Sanfeliu-Cerdán
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Frederic Català-Castro
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Borja Mateos
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Carla Garcia-Cabau
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Maria Ribera
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Iris Ruider
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Montserrat Porta-de-la-Riva
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Adrià Canals-Calderón
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Stefan Wieser
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Xavier Salvatella
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - Michael Krieg
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain.
| |
Collapse
|