1
|
Liprins in oncogenic signaling and cancer cell adhesion. Oncogene 2021; 40:6406-6416. [PMID: 34654889 PMCID: PMC8602034 DOI: 10.1038/s41388-021-02048-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/21/2021] [Accepted: 09/28/2021] [Indexed: 12/30/2022]
Abstract
Liprins are a multifunctional family of scaffold proteins, identified by their involvement in several important neuronal functions related to signaling and organization of synaptic structures. More recently, the knowledge on the liprin family has expanded from neuronal functions to processes relevant to cancer progression, including cell adhesion, cell motility, cancer cell invasion, and signaling. These proteins consist of regions, which by prediction are intrinsically disordered, and may be involved in the assembly of supramolecular structures relevant for their functions. This review summarizes the current understanding of the functions of liprins in different cellular processes, with special emphasis on liprins in tumor progression. The available data indicate that liprins may be potential biomarkers for cancer progression and may have therapeutic importance.
Collapse
|
2
|
Ramella M, Ribolla LM, de Curtis I. Liquid-Liquid Phase Separation at the Plasma Membrane-Cytosol Interface: Common Players in Adhesion, Motility, and Synaptic Function. J Mol Biol 2021; 434:167228. [PMID: 34487789 DOI: 10.1016/j.jmb.2021.167228] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 01/09/2023]
Abstract
Networks of scaffold proteins and enzymes assemble at the interface between the cytosol and specific sites of the plasma membrane, where these networks guide distinct cellular functions. Some of these plasma membrane-associated platforms (PMAPs) include shared core components that are able to establish specific protein-protein interactions, to produce distinct supramolecular assemblies regulating dynamic processes as diverse as cell adhesion and motility, or the formation and function of neuronal synapses. How cells organize such dynamic networks is still an open question. In this review we introduce molecular networks assembling at the edge of migrating cells, and at pre- and postsynaptic sites, which share molecular players that can drive the assembly of biomolecular condensates. Very recent experimental evidence has highlighted the emerging role of some of these multidomain/scaffold proteins belonging to the GIT, liprin-α and ELKS/ERC families as drivers of liquid-liquid phase separation (LLPS). The data point to an important role of LLPS: (i) in the formation of PMAPs at the edge of migrating cells, where LLPS appears to be involved in promoting protrusion and the turnover of integrin-mediated adhesions, to allow forward cell translocation; (ii) in the assembly of the presynaptic active zone and of the postsynaptic density deputed to the release and reception of neurotransmitter signals, respectively. The recent results indicate that LLPS at cytosol-membrane interfaces is suitable not only for the regulation of active cellular processes, but also for the continuous spatial rearrangements of the molecular interactions involved in these dynamic processes.
Collapse
Affiliation(s)
- Martina Ramella
- Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Via Olgettina, 58, 20132 Milano, Italy.
| | - Lucrezia Maria Ribolla
- Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Via Olgettina, 58, 20132 Milano, Italy.
| | - Ivan de Curtis
- Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Via Olgettina, 58, 20132 Milano, Italy.
| |
Collapse
|
3
|
Xie X, Liang M, Yu C, Wei Z. Liprin-α-Mediated Assemblies and Their Roles in Synapse Formation. Front Cell Dev Biol 2021; 9:653381. [PMID: 33869211 PMCID: PMC8044993 DOI: 10.3389/fcell.2021.653381] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 02/25/2021] [Indexed: 01/20/2023] Open
Abstract
Brain's functions, such as memory and learning, rely on synapses that are highly specialized cellular junctions connecting neurons. Functional synapses orchestrate the assembly of ion channels, receptors, enzymes, and scaffold proteins in both pre- and post-synapse. Liprin-α proteins are master scaffolds in synapses and coordinate various synaptic proteins to assemble large protein complexes. The functions of liprin-αs in synapse formation have been largely uncovered by genetic studies in diverse model systems. Recently, emerging structural and biochemical studies on liprin-α proteins and their binding partners begin to unveil the molecular basis of the synaptic assembly. This review summarizes the recent structural findings on liprin-αs, proposes the assembly mechanism of liprin-α-mediated complexes, and discusses the liprin-α-organized assemblies in the regulation of synapse formation and function.
Collapse
Affiliation(s)
- Xingqiao Xie
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China
| | - Mingfu Liang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Cong Yu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, China
| | - Zhiyi Wei
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
| |
Collapse
|
4
|
Liang M, Xie X, Pan J, Jin G, Yu C, Wei Z. Structural basis of the target-binding mode of the G protein-coupled receptor kinase-interacting protein in the regulation of focal adhesion dynamics. J Biol Chem 2019; 294:5827-5839. [PMID: 30737283 DOI: 10.1074/jbc.ra118.006915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/04/2019] [Indexed: 12/27/2022] Open
Abstract
Focal adhesions (FAs) are specialized sites where intracellular cytoskeleton elements connect to the extracellular matrix and thereby control cell motility. FA assembly depends on various scaffold proteins, including the G protein-coupled receptor kinase-interacting protein 1 (GIT1), paxillin, and liprin-α. Although liprin-α and paxillin are known to competitively interact with GIT1, the molecular basis governing these interactions remains elusive. To uncover the underlying mechanisms of how GIT1 is involved in FA assembly by alternatively binding to liprin-α and paxillin, here we solved the crystal structures of GIT1 in complex with liprin-α and paxillin at 1.8 and 2.6 Å resolutions, respectively. These structures revealed that the paxillin-binding domain (PBD) of GIT1 employs distinct binding modes to recognize a single α-helix of liprin-α and the LD4 motif of paxillin. Structure-based design of protein variants produced two binding-deficient GIT1 variants; specifically, these variants lost the ability to interact with liprin-α only or with both liprin-α and paxillin. Expressing the GIT1 variants in COS7 cells, we discovered that the two PBD-meditated interactions play different roles in either recruiting GIT1 to FA or facilitating FA assembly. Additionally, we demonstrate that, unlike for the known binding mode of the FAT domain to LD motifs, the PBD of GIT1 uses different surface patches to achieve high selectivity in LD motif recognition. In summary, our results have uncovered the mechanisms by which GIT1's PBD recognizes cognate paxillin and liprin-α structures, information we anticipate will be useful for future investigations of GIT1-protein interactions in cells.
Collapse
Affiliation(s)
- Mingfu Liang
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xingqiao Xie
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jian Pan
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Gaowei Jin
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Cong Yu
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China; the Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen 518055, China; the Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen 518055, China.
| | - Zhiyi Wei
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China.
| |
Collapse
|
5
|
Franchi SA, Astro V, Macco R, Tonoli D, Barnier JV, Botta M, de Curtis I. Identification of a Protein Network Driving Neuritogenesis of MGE-Derived GABAergic Interneurons. Front Cell Neurosci 2016; 10:289. [PMID: 28066185 PMCID: PMC5174131 DOI: 10.3389/fncel.2016.00289] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/02/2016] [Indexed: 12/27/2022] Open
Abstract
Interneurons are essential modulators of brain activity and their abnormal maturation may lead to neural and intellectual disabilities. Here we show that cultures derived from murine medial ganglionic eminences (MGEs) produce virtually pure, polarized γ-aminobutyric acid (GABA)-ergic interneurons that can form morphologically identifiable inhibitory synapses. We show that Rac GTPases and a protein complex including the GIT family scaffold proteins are expressed during maturation in vitro, and are required for the normal development of neurites. GIT1 promotes neurite extension in a conformation-dependent manner, while affecting its interaction with specific partners reduces neurite branching. Proteins of the GIT network are concentrated at growth cones, and interaction mutants may affect growth cone behavior. Our findings identify the PIX/GIT1/liprin-α1/ERC1 network as critical for the regulation of interneuron neurite differentiation in vitro, and show that these cultures represent a valuable system to identify the molecular mechanisms driving the maturation of cortical/hippocampal interneurons.
Collapse
Affiliation(s)
- Sira A Franchi
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Veronica Astro
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Romina Macco
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Diletta Tonoli
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Jean-Vianney Barnier
- Neuroscience Paris-Saclay Institute, UMR 9197, Centre National de la Recherche Scientifique-Université Paris-Sud Orsay, France
| | - Martina Botta
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Ivan de Curtis
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| |
Collapse
|
6
|
Liprin-α1 and ERC1 control cell edge dynamics by promoting focal adhesion turnover. Sci Rep 2016; 6:33653. [PMID: 27659488 PMCID: PMC5034239 DOI: 10.1038/srep33653] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/31/2016] [Indexed: 11/08/2022] Open
Abstract
Liprin-α1 and ERC1 are interacting scaffold proteins regulating the motility of normal and tumor cells. They act as part of plasma membrane-associated platforms at the edge of motile cells to promote protrusion by largely unknown mechanisms. Here we identify an amino-terminal region of the liprin-α1 protein (liprin-N) that is sufficient and necessary for the interaction with other liprin-α1 molecules. Similar to liprin-α1 or ERC1 silencing, expression of the liprin-N negatively affects tumor cell motility and extracellular matrix invasion, acting as a dominant negative by interacting with endogenous liprin-α1 and causing the displacement of the endogenous ERC1 protein from the cell edge. Interfering with the localization of ERC1 at the cell edge inhibits the disassembly of focal adhesions, impairing protrusion. Liprin-α1 and ERC1 proteins colocalize with active integrin β1 clusters distinct from those colocalizing with cytoplasmic focal adhesion proteins, and influence the localization of peripheral Rab7-positive endosomes. We propose that liprin-α1 and ERC1 promote protrusion by displacing cytoplasmic adhesion components to favour active integrin internalization into Rab7-positive endosomes.
Collapse
|
7
|
Astro V, de Curtis I. Plasma membrane-associated platforms: Dynamic scaffolds that organize membrane-associated events. Sci Signal 2015; 8:re1. [DOI: 10.1126/scisignal.aaa3312] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
8
|
de Curtis I, Meldolesi J. Cell surface dynamics – how Rho GTPases orchestrate the interplay between the plasma membrane and the cortical cytoskeleton. J Cell Sci 2012; 125:4435-44. [DOI: 10.1242/jcs.108266] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Small GTPases are known to regulate hundreds of cell functions. In particular, Rho family GTPases are master regulators of the cytoskeleton. By regulating actin nucleation complexes, Rho GTPases control changes in cell shape, including the extension and/or retraction of surface protrusions and invaginations. Protrusion and invagination of the plasma membrane also involves the interaction between the plasma membrane and the cortical cytoskeleton. This interplay between membranes and the cytoskeleton can lead to an increase or decrease in the plasma membrane surface area and its tension as a result of the fusion (exocytosis) or internalization (endocytosis) of membranous compartments, respectively. For a long time, the cytoskeleton and plasma membrane dynamics were investigated separately. However, studies from many laboratories have now revealed that Rho GTPases, their modulation of the cytoskeleton, and membrane traffic are closely connected during the dynamic remodeling of the cell surface. Arf- and Rab-dependent exocytosis of specific vesicles contributes to the targeting of Rho GTPases and their regulatory factors to discrete sites of the plasma membrane. Rho GTPases regulate the tethering of exocytic vesicles and modulate their subsequent fusion. They also have crucial roles in the different forms of endocytosis, where they participate in the sorting of membrane domains as well as the sculpting and sealing of membrane flasks and cups. Here, we discuss how cell surface dynamics depend on the orchestration of the cytoskeleton and the plasma membrane by Rho GTPases.
Collapse
|