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Chen X, Seyboldt R, Sommer JU, Jülicher F, Harmon T. Droplet Differentiation by a Chemical Switch. PHYSICAL REVIEW LETTERS 2024; 133:028402. [PMID: 39073969 DOI: 10.1103/physrevlett.133.028402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 05/29/2024] [Indexed: 07/31/2024]
Abstract
A fundamental question about biomolecular condensates is how distinct condensates can emerge from the interplay of different components. Here we present a minimal model of droplet differentiation where phase separated droplets demix into two types with different chemical modifications triggered by enzymatic reactions. We use numerical solutions to Cahn-Hilliard equations with chemical reactions and an effective droplet model to reveal the switchlike behavior. Our work shows how condensate identities in cells could result from competing enzymatic actions.
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Affiliation(s)
| | | | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung, Institut Theorie der Polymere, 01069 Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany
- Institute for Theoretical Physics, TU Dresden, Zellescher Weg 17, 01069 Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzerstrasse 38, 01187 Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
- Center for Systems Biology Dresden, 01307 Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany
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Nguyen TTT, Tokuhiro K, Shimada K, Wang H, Mashiko D, Tonai S, Kiyozumi D, Ikawa M. Gene-deficient mouse model established by CRISPR/Cas9 system reveals 15 reproductive organ-enriched genes dispensable for male fertility. Front Cell Dev Biol 2024; 12:1411162. [PMID: 38835510 PMCID: PMC11148293 DOI: 10.3389/fcell.2024.1411162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 05/02/2024] [Indexed: 06/06/2024] Open
Abstract
Since the advent of gene-targeting technology in embryonic stem cells, mice have become a primary model organism for investigating human gene function due to the striking genomic similarities between the two species. With the introduction of the CRISPR/Cas9 system for genome editing in mice, the pace of loss-of-function analysis has accelerated significantly. This has led to the identification of numerous genes that play crucial roles in male reproductive processes, including meiosis, chromatin condensation, flagellum formation in the testis, sperm maturation in the epididymis, and fertilization in the oviduct. Despite the advancements, the functions of many genes, particularly those enriched in male reproductive tissues, remain largely unknown. In our study, we focused on 15 genes and generated 13 gene-deficient mice [4933411K16Rik, Adam triple (Adam20, Adam25, and Adam39), BC048671, Cfap68, Gm4846, Gm4984, Gm13570, Nt5c1b, Ppp1r42, Saxo4, Sh3d21, Spz1, and Tektl1] to elucidate their roles in male fertility. Surprisingly, all 13 gene-deficient mice exhibited normal fertility in natural breeding experiments, indicating that these genes are not essential for male fertility. These findings have important implications as they may help prevent other research laboratories from duplicating efforts to generate knockout mice for genes that do not demonstrate an apparent phenotype related to male fertility. By shedding light on the dispensability of these genes, our study contributes to a more efficient allocation of research resources in the exploration of male reproductive biology.
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Affiliation(s)
- Tuyen Thi Thanh Nguyen
- Department of Genome Editing, Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
| | - Keizo Tokuhiro
- Department of Genome Editing, Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
| | - Keisuke Shimada
- Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Haoting Wang
- Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Daisuke Mashiko
- Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Shingo Tonai
- Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Daiji Kiyozumi
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Tokyo, Japan
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| | - Masahito Ikawa
- Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
- Center for Infectious Disease Education and Research, Osaka University, Osaka, Japan
- The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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Levillayer L, Brighelli C, Demeret C, Sakuntabhai A, Bureau JF. Role of two modules controlling the interaction between SKAP1 and SRC kinases comparison with SKAP2 architecture and consequences for evolution. PLoS One 2024; 19:e0296230. [PMID: 38483858 PMCID: PMC10939263 DOI: 10.1371/journal.pone.0296230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/28/2024] [Indexed: 03/17/2024] Open
Abstract
SRC kinase associated phosphoprotein 1 (SKAP1), an adaptor for protein assembly, plays an important role in the immune system such as stabilizing immune synapses. Understanding how these functions are controlled at the level of the protein-protein interactions is necessary to describe these processes and to develop therapeutics. Here, we dissected the SKAP1 modular organization to recognize SRC kinases and compared it to that of its paralog SRC kinase associated phosphoprotein 2 (SKAP2). Different conserved motifs common to either both proteins or specific to SKAP2 were found using this comparison. Two modules harboring different binding properties between SKAP1 and SKAP2 were identified: one composed of two conserved motifs located in the second interdomain interacting at least with the SH2 domain of SRC kinases and a second one composed of the DIM domain modulated by the SH3 domain and the activation of SRC kinases. This work suggests a convergent evolution of the binding properties of some SRC kinases interacting specifically with either SKAP1 or SKAP2.
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Affiliation(s)
- Laurine Levillayer
- Institut Pasteur, Institut National de Recherche pour l’Agriculture, Université de Paris-Cité, CNRS UMR 2000, l’Alimentation et l’Environnement (INRAE) USC 1510, Unité Écologie et Émergence des Pathogènes Transmis par les Arthropodes (EEPTA), Paris, France
| | - Camille Brighelli
- Institut Pasteur, Institut National de Recherche pour l’Agriculture, Université de Paris-Cité, CNRS UMR 2000, l’Alimentation et l’Environnement (INRAE) USC 1510, Unité Écologie et Émergence des Pathogènes Transmis par les Arthropodes (EEPTA), Paris, France
| | - Caroline Demeret
- Institut Pasteur, Université de Paris-Cité, Laboratoire Interactomique, ARN et Immunité ‐ Interactomics, RNA and Immunity, Paris, France
| | - Anavaj Sakuntabhai
- Institut Pasteur, Institut National de Recherche pour l’Agriculture, Université de Paris-Cité, CNRS UMR 2000, l’Alimentation et l’Environnement (INRAE) USC 1510, Unité Écologie et Émergence des Pathogènes Transmis par les Arthropodes (EEPTA), Paris, France
| | - Jean-François Bureau
- Institut Pasteur, Institut National de Recherche pour l’Agriculture, Université de Paris-Cité, CNRS UMR 2000, l’Alimentation et l’Environnement (INRAE) USC 1510, Unité Écologie et Émergence des Pathogènes Transmis par les Arthropodes (EEPTA), Paris, France
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Brunet T, Booth DS. Cell polarity in the protist-to-animal transition. Curr Top Dev Biol 2023; 154:1-36. [PMID: 37100515 DOI: 10.1016/bs.ctdb.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
A signature feature of the animal kingdom is the presence of epithelia: sheets of polarized cells that both insulate the organism from its environment and mediate interactions with it. Epithelial cells display a marked apico-basal polarity, which is highly conserved across the animal kingdom, both in terms of morphology and of molecular regulators. How did this architecture first evolve? Although the last eukaryotic common ancestor almost certainly possessed a simple form of apico-basal polarity (marked by the presence of one or several flagella at a single cellular pole), comparative genomics and evolutionary cell biology reveal that the polarity regulators of animal epithelial cells have a surprisingly complex and stepwise evolutionary history. Here, we retrace their evolutionary assembly. We suggest that the "polarity network" that polarized animal epithelial cells evolved by integration of initially independent cellular modules that evolved at distinct steps of our evolutionary ancestry. The first module dates back to the last common ancestor of animals and amoebozoans and involved Par1, extracellular matrix proteins, and the integrin-mediated adhesion complex. Other regulators, such as Cdc42, Dlg, Par6 and cadherins evolved in ancient unicellular opisthokonts, and might have first been involved in F-actin remodeling and filopodial dynamics. Finally, the bulk of "polarity proteins" as well as specialized adhesion complexes evolved in the metazoan stem-line, in concert with the newly evolved intercellular junctional belts. Thus, the polarized architecture of epithelia can be understood as a palimpsest of components of distinct histories and ancestral functions, which have become tightly integrated in animal tissues.
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Liu W, Liu B, Zhang G, Jia H, Zhang Y, Cen X, Yao G, He M. Molecular and Functional Characterization of a Short-Type Peptidoglycan Recognition Protein, Ct-PGRP-S1 in the Giant Triton Snail Charonia tritonis. Int J Mol Sci 2022; 23:11062. [PMID: 36232364 PMCID: PMC9570181 DOI: 10.3390/ijms231911062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 11/22/2022] Open
Abstract
Peptidoglycan recognition proteins (PGRPs) are a family of pattern recognition receptors (PRRs) involved in host antibacterial responses, and their functions have been characterized in most invertebrate and vertebrate animals. However, little information is available regarding the potential function of PGRPs in the giant triton snail Charonia tritonis. In this study, a short-type PGRP gene (termed Ct-PGRP-S1) was identified in C. tritonis. Ct-PGRP-S1 was predicted to contain several structural features known in PGRPs, including a typical PGRP domain (Amidase_2) and Src homology-3 (SH3) domain. The Ct-PGRP-S1 gene was constitutively expressed in all tissues examined except in proboscis, with the highest expression level observed in the liver. As a typical PRR, Ct-PGRP-S1 has an ability to degrade peptidoglycan (PGN) and was proven to have non-Zn2+-dependent amidase activity and antibacterial activity against Vibrioalginolyticus and Staphylococcus aureus. It is the first report to reveal the peptidoglycan recognition protein in C. tritonis, and these results suggest that peptidoglycan recognition protein Ct-PGRP-S1 is an important effector of C. tritonis that modulates bacterial infection resistance of V. alginolyticus and S. aureus, and this study may provide crucial basic data for the understanding of an innate immunity system of C. tritonis.
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Affiliation(s)
- Wenguang Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Bing Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gege Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huixia Jia
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Xitong Cen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gaoyou Yao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Maoxian He
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
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Impact of a conserved N-terminal proline-rich region of the α-subunit of CAAX-prenyltransferases on their enzyme properties. Cell Commun Signal 2022; 20:118. [PMID: 35941619 PMCID: PMC9358863 DOI: 10.1186/s12964-022-00929-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/05/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The CAAX-prenyltransferases farnesyltransferase (FTase) and geranylgeranyltransferase I (GGTase I) are heterodimers with a common α- (FTα) and unique β-subunits. Recently, α-subunits of species (e.g., human) that harbour an N-terminal proline-rich region (PRR) showed different dimerization behaviours than α-subunits without PRR (e.g., yeast). However, the specific function of the PRR has not been elucidated so far. METHODS To determine whether the PRR is a conserved motif throughout eukaryotes, we performed phylogenetics. Elucidating the impact of the PRR on enzyme properties, we cloned human as well as rat PRR deficient FTα, expressed them heterologously and compared protein-protein interaction by pull-down as well as crosslinking experiments. Substrate binding, enzyme activity and sensitivity towards common FTase inhibitors of full length and PRR-deletion α-subunits and their physiological partners was determined by continuous fluorescence assays. RESULTS The PRR is highly conserved in mammals, with an exception for marsupials harbouring a poly-alanine region instead. The PRR shows similarities to canonical SH3-binding domains and to profilin-binding domains. Independent of the PRR, the α-subunits were able to dimerize with the different physiological β-subunits in in vitro as well as in yeast two-hybrid experiments. FTase and GGTase I with truncated FTα were active. The KM values for both substrates are in the single-digit µM range and show no significant differences between enzymes with full length and PRR deficient α-subunits within the species. CONCLUSIONS Our data demonstrate that an N-terminal PRR of FTα is highly conserved in mammals. We could show that the activity and inhibitability is not influenced by the truncation of the N-terminal region. Nevertheless, this region shows common binding motifs for other proteins involved in cell-signalling, trafficking and phosphorylation, suggesting that this PRR might have other or additional functions in mammals. Our results provide new starting points due to the relevant but only partly understood role of FTα in eukaryotic FTase and GGTase I. Video Abstract.
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Molina-Pelayo C, Olguin P, Mlodzik M, Glavic A. The conserved Pelado/ZSWIM8 protein regulates actin dynamics by promoting linear actin filament polymerization. Life Sci Alliance 2022; 5:e202201484. [PMID: 35940847 PMCID: PMC9375228 DOI: 10.26508/lsa.202201484] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Actin filament polymerization can be branched or linear, which depends on the associated regulatory proteins. Competition for actin monomers occurs between proteins that induce branched or linear actin polymerization. Cell specialization requires the regulation of actin filaments to allow the formation of cell type-specific structures, like cuticular hairs in <i>Drosophila</i>, formed by linear actin filaments. Here, we report the functional analysis of CG34401/<i>pelado</i>, a gene encoding a SWIM domain-containing protein, conserved throughout the animal kingdom, called ZSWIM8 in mammals. Mutant <i>pelado</i> epithelial cells display actin hair elongation defects. This phenotype is reversed by increasing actin monomer levels or by either pushing linear actin polymerization or reducing branched actin polymerization. Similarly, in hemocytes, Pelado is essential to induce filopodia, a linear actin-based structure. We further show that this function of Pelado/ZSWIM8 is conserved in human cells, where Pelado inhibits branched actin polymerization in a cell migration context. In summary, our data indicate that the function of Pelado/ZSWIM8 in regulating actin cytoskeletal dynamics is conserved, favoring linear actin polymerization at the expense of branched filaments.
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Affiliation(s)
- Claudia Molina-Pelayo
- Department of Cell, Developmental, and Regenerative Biology, Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Departamento de Biología, Centro FONDAP de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Patricio Olguin
- Department of Cell, Developmental, and Regenerative Biology, Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Departamento de Neurociencia, Programa de Genética Humana, Instituto de Ciencias Biomédicas, Instituto de Neurociencia Biomédica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Marek Mlodzik
- Department of Cell, Developmental, and Regenerative Biology, Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Alvaro Glavic
- Departamento de Biología, Centro FONDAP de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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Oncogenic Signalling of PEAK2 Pseudokinase in Colon Cancer. Cancers (Basel) 2022; 14:cancers14122981. [PMID: 35740644 PMCID: PMC9221080 DOI: 10.3390/cancers14122981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/05/2022] [Accepted: 06/13/2022] [Indexed: 11/22/2022] Open
Abstract
Simple Summary Catalytically inactive kinases, also named pseudokinases, play important roles in the regulation of cell growth and adhesion. While frequently deregulated in human cancer, their role in tumour development is partially elucidated. Here, we report an important tumour function for the pseudokinase PEAK2 in colorectal cancer (CRC) and propose that PEAK2 upregulation can affect cancer cell adhesive properties through an ABL-dependent mechanism to enable cancer progression. Therefore, targeting PEAK2 oncogenic activity with small tyrosine kinases (TK) inhibitors may be of therapeutic interest in colorectal cancer (CRC). Abstract The PEAK family pseudokinases are essential components of tyrosine kinase (TK) pathways that regulate cell growth and adhesion; however, their role in human cancer remains unclear. Here, we report an oncogenic activity of the pseudokinase PEAK2 in colorectal cancer (CRC). Notably, high PRAG1 expression, which encodes PEAK2, was associated with a bad prognosis in CRC patients. Functionally, PEAK2 depletion reduced CRC cell growth and invasion in vitro, while its overexpression increased these transforming effects. PEAK2 depletion also reduced CRC development in nude mice. Mechanistically, PEAK2 expression induced cellular protein tyrosine phosphorylation, despite its catalytic inactivity. Phosphoproteomic analysis identified regulators of cell adhesion and F-actin dynamics as PEAK2 targets. Additionally, PEAK2 was identified as a novel ABL TK activator. In line with this, PEAK2 expression localized at focal adhesions of CRC cells and induced ABL-dependent formation of actin-rich plasma membrane protrusions filopodia that function to drive cell invasion. Interestingly, all these PEAK2 transforming activities were regulated by its main phosphorylation site, Tyr413, which implicates the SRC oncogene. Thus, our results uncover a protumoural function of PEAK2 in CRC and suggest that its deregulation affects adhesive properties of CRC cells to enable cancer progression.
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Dionne U, Percival LJ, Chartier FJM, Landry CR, Bisson N. SRC homology 3 domains: multifaceted binding modules. Trends Biochem Sci 2022; 47:772-784. [PMID: 35562294 DOI: 10.1016/j.tibs.2022.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/30/2022] [Accepted: 04/11/2022] [Indexed: 12/15/2022]
Abstract
The assembly of complexes following the detection of extracellular signals is often controlled by signaling proteins comprising multiple peptide binding modules. The SRC homology (SH)3 family represents the archetypical modular protein interaction module, with ~300 annotated SH3 domains in humans that regulate an impressive array of signaling processes. We review recent findings regarding the allosteric contributions of SH3 domains host protein context, their phosphoregulation, and their roles in phase separation that challenge the simple model in which SH3s are considered to be portable domains binding to specific proline-rich peptide motifs.
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Affiliation(s)
- Ugo Dionne
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada
| | - Lily J Percival
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada; School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Manchester, UK
| | - François J M Chartier
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada
| | - Christian R Landry
- Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada; Institute of Integrative and Systems Biology, Université Laval, Quebec, QC, Canada; Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Quebec, QC, Canada; Department of Biology, Université Laval, Quebec, QC, Canada.
| | - Nicolas Bisson
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Quebec, QC, Canada.
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Novel Roles of SH2 and SH3 Domains in Lipid Binding. Cells 2021; 10:cells10051191. [PMID: 34068055 PMCID: PMC8152464 DOI: 10.3390/cells10051191] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 01/07/2023] Open
Abstract
Signal transduction, the ability of cells to perceive information from the surroundings and alter behavior in response, is an essential property of life. Studies on tyrosine kinase action fundamentally changed our concept of cellular regulation. The induced assembly of subcellular hubs via the recognition of local protein or lipid modifications by modular protein interactions is now a central paradigm in signaling. Such molecular interactions are mediated by specific protein interaction domains. The first such domain identified was the SH2 domain, which was postulated to be a reader capable of finding and binding protein partners displaying phosphorylated tyrosine side chains. The SH3 domain was found to be involved in the formation of stable protein sub-complexes by constitutively attaching to proline-rich surfaces on its binding partners. The SH2 and SH3 domains have thus served as the prototypes for a diverse collection of interaction domains that recognize not only proteins but also lipids, nucleic acids, and small molecules. It has also been found that particular SH2 and SH3 domains themselves might also bind to and rely on lipids to modulate complex assembly. Some lipid-binding properties of SH2 and SH3 domains are reviewed here.
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Hallumi E, Shalah R, Lo WL, Corso J, Oz I, Beach D, Wittman S, Isenberg A, Sela M, Urlaub H, Weiss A, Yablonski D. Itk Promotes the Integration of TCR and CD28 Costimulation through Its Direct Substrates SLP-76 and Gads. THE JOURNAL OF IMMUNOLOGY 2021; 206:2322-2337. [PMID: 33931484 DOI: 10.4049/jimmunol.2001053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 03/15/2021] [Indexed: 11/19/2022]
Abstract
The costimulatory receptor CD28 synergizes with the TCR to promote IL-2 production, cell survival, and proliferation; yet the obligatory interdependence of TCR and CD28 signaling is not well understood. Upon TCR stimulation, Gads, a Grb2-family adaptor, bridges the interaction of two additional adaptors, LAT and SLP-76, to form a TCR-induced effector signaling complex. SLP-76 binds the Tec-family tyrosine kinase, Itk, which phosphorylates SLP-76 Y173 and PLC-γ1 Y783. In this study, we identified TCR-inducible, Itk-mediated phosphorylation of Gads Y45 in a human T cell line and in mouse primary T cells. Y45 is found within the N-terminal SH3 domain of Gads, an evolutionarily conserved domain with no known signaling function. Gads Y45 phosphorylation depended on the interaction of Gads with SLP-76 and on the dimerization-dependent binding of Gads to phospho-LAT. We provide evidence that Itk acts through SLP-76 and Gads to promote the TCR/CD28-induced activation of the RE/AP transcriptional element from the IL-2 promoter. Two Itk-related features of SLP-76, Y173 and a proline-rich Itk SH3 binding motif on SLP-76, were dispensable for activation of NFAT but selectively required for the TCR/CD28-induced increase in cytoplasmic and nuclear c-Rel and consequent RE/AP activation. We provide evidence that unphosphorylated, monomeric Gads mediates an RE/AP-directed inhibitory activity that is mitigated upon Gads dimerization and Y45 phosphorylation. This study illuminates a new, to our knowledge, regulatory module, in which TCR-induced, Itk-mediated phosphorylation sites on SLP-76 and Gads control the transcriptional response to TCR/CD28 costimulation, thus enforcing the obligatory interdependence of the TCR and CD28 signaling pathways.
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Affiliation(s)
- Enas Hallumi
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Rose Shalah
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Wan-Lin Lo
- Rosalind Russell and Ephraim P. Engleman Arthritis Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Jasmin Corso
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ilana Oz
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Dvora Beach
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Samuel Wittman
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Amy Isenberg
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Meirav Sela
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics Research Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Arthur Weiss
- Rosalind Russell and Ephraim P. Engleman Arthritis Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, San Francisco, CA.,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Deborah Yablonski
- Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
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12
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Těšický M, Velová H, Novotný M, Kreisinger J, Beneš V, Vinkler M. Positive selection and convergent evolution shape molecular phenotypic traits of innate immunity receptors in tits (Paridae). Mol Ecol 2020; 29:3056-3070. [PMID: 32652716 DOI: 10.1111/mec.15547] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/09/2020] [Accepted: 06/26/2020] [Indexed: 01/04/2023]
Abstract
Despite widespread variability and redundancy abounding animal immunity, little is currently known about the rate of evolutionary convergence (functionally analogous traits not inherited from a common ancestor) in host molecular adaptations to parasite selective pressures. Toll-like receptors (TLRs) provide the molecular interface allowing hosts to recognize pathogenic structures and trigger early danger signals initiating an immune response. Using a novel combination of bioinformatic approaches, here we explore genetic variation in ligand-binding regions of bacteria-sensing TLR4 and TLR5 in 29 species belonging to the tit family of passerine birds (Aves: Paridae). Three out of the four consensual positively selected sites in TLR4 and six out of 14 positively selected positions in TLR5 were located on the receptor surface near the functionally important sites, and based on the phylogenetic pattern evolved in a convergent (parallel) manner. This type of evolution was also seen at one N-glycosylation site and two positively selected phosphorylation sites, providing the first evidence of convergence in post-translational modifications in evolutionary immunology. Finally, the overall mismatch between phylogeny and the clustering of surface charge distribution demonstrates that convergence is common in overall TLR4 and TLR5 molecular phenotypes involved in ligand binding. Our analysis did not reveal any broad ecological traits explaining the convergence observed in electrostatic potentials, suggesting that information on microbial symbionts may be needed to explain TLR evolution. Adopting state-of-the-art predictive structural bionformatics, we have outlined a new broadly applicable methodological approach to estimate the functional significance of positively selected variation and test for the adaptive molecular convergence in protein-coding polymorphisms.
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Affiliation(s)
- Martin Těšický
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Hana Velová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Marian Novotný
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jakub Kreisinger
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Vladimír Beneš
- European Molecular Laboratory Heidelberg, Heidelberg, Germany
| | - Michal Vinkler
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
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13
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Cai ML, Wang MY, Zhang CH, Wang JX, Liu H, He HW, Zhao WL, Xia GM, Shao RG. Role of co- and post-translational modifications of SFKs in their kinase activation. J Drug Target 2019; 28:23-32. [PMID: 31094236 DOI: 10.1080/1061186x.2019.1616297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Src family kinases (SFKs) are non-receptor tyrosine kinases and are involved in various cellular functions (proliferation, differentiation, migration, survival and invasion) by regulating downstream pathways. Considerable evidence suggests that co- and post-translational modifications are highly related to the activation of SFKs and their downstream signals. How SFKs are activated and how their subsequent cascades were regulated has been reviewed in previous reports. However, the contribution of co- and post-translational modification to SFKs activation has not been fully elucidated. This review focuses on the effect of these modifications on SFKs activity according to structural and biochemical studies and uncovers the significance of co-and post-translational modifications in the regulation of SFKs activity.
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Affiliation(s)
- Mei-Lian Cai
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Meng-Yan Wang
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Cong-Hui Zhang
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Jun-Xia Wang
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Hong Liu
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Hong-Wei He
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Wu-Li Zhao
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Gui-Ming Xia
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Rong-Guang Shao
- China Academy of Medical Sciences, Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
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14
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Gerth F, Jäpel M, Sticht J, Kuropka B, Schmitt XJ, Driller JH, Loll B, Wahl MC, Pagel K, Haucke V, Freund C. Exon Inclusion Modulates Conformational Plasticity and Autoinhibition of the Intersectin 1 SH3A Domain. Structure 2019; 27:977-987.e5. [DOI: 10.1016/j.str.2019.03.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 01/21/2019] [Accepted: 03/25/2019] [Indexed: 11/16/2022]
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15
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Merő B, Radnai L, Gógl G, Tőke O, Leveles I, Koprivanacz K, Szeder B, Dülk M, Kudlik G, Vas V, Cserkaszky A, Sipeki S, Nyitray L, Vértessy BG, Buday L. Structural insights into the tyrosine phosphorylation-mediated inhibition of SH3 domain-ligand interactions. J Biol Chem 2019; 294:4608-4620. [PMID: 30659095 DOI: 10.1074/jbc.ra118.004732] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 01/17/2019] [Indexed: 01/01/2023] Open
Abstract
Src homology 3 (SH3) domains bind proline-rich linear motifs in eukaryotes. By mediating inter- and intramolecular interactions, they regulate the functions of many proteins involved in a wide variety of signal transduction pathways. Phosphorylation at different tyrosine residues in SH3 domains has been reported previously. In several cases, the functional consequences have also been investigated. However, a full understanding of the effects of tyrosine phosphorylation on the ligand interactions and cellular functions of SH3 domains requires detailed structural, atomic-resolution studies along with biochemical and biophysical analyses. Here, we present the first crystal structures of tyrosine-phosphorylated human SH3 domains derived from the Abelson-family kinases ABL1 and ABL2 at 1.6 and 1.4 Å resolutions, respectively. The structures revealed that simultaneous phosphorylation of Tyr89 and Tyr134 in ABL1 or the homologous residues Tyr116 and Tyr161 in ABL2 induces only minor structural perturbations. Instead, the phosphate groups sterically blocked the ligand-binding grooves, thereby strongly inhibiting the interaction with proline-rich peptide ligands. Although some crystal contact surfaces involving phosphotyrosines suggested the possibility of tyrosine phosphorylation-induced dimerization, we excluded this possibility by using small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and NMR relaxation analyses. Extensive analysis of relevant databases and literature revealed not only that the residues phosphorylated in our model systems are well-conserved in other human SH3 domains, but that the corresponding tyrosines are known phosphorylation sites in vivo in many cases. We conclude that tyrosine phosphorylation might be a mechanism involved in the regulation of the human SH3 interactome.
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Affiliation(s)
| | | | - Gergő Gógl
- the Department of Biochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest H-1117, Hungary
| | - Orsolya Tőke
- Laboratory for NMR Spectroscopy, Research Center for Natural Sciences (RCNS), Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest H-1117, Hungary
| | - Ibolya Leveles
- From the Institute of Enzymology and.,the Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Szt. Gellért tér 4, Budapest H-1111, Hungary, and
| | | | | | | | | | - Virág Vas
- From the Institute of Enzymology and
| | | | - Szabolcs Sipeki
- the Department of Medical Chemistry, Semmelweis University Medical School, Tűzoltó u. 37-47, Budapest H-1094, Hungary
| | - László Nyitray
- the Department of Biochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest H-1117, Hungary
| | - Beáta G Vértessy
- From the Institute of Enzymology and.,the Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Szt. Gellért tér 4, Budapest H-1111, Hungary, and
| | - László Buday
- From the Institute of Enzymology and .,the Department of Medical Chemistry, Semmelweis University Medical School, Tűzoltó u. 37-47, Budapest H-1094, Hungary
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16
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Dionne U, Chartier FJM, López de Los Santos Y, Lavoie N, Bernard DN, Banerjee SL, Otis F, Jacquet K, Tremblay MG, Jain M, Bourassa S, Gish GD, Gagné JP, Poirier GG, Laprise P, Voyer N, Landry CR, Doucet N, Bisson N. Direct Phosphorylation of SRC Homology 3 Domains by Tyrosine Kinase Receptors Disassembles Ligand-Induced Signaling Networks. Mol Cell 2018; 70:995-1007.e11. [PMID: 29910111 PMCID: PMC6014926 DOI: 10.1016/j.molcel.2018.05.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 03/20/2018] [Accepted: 05/10/2018] [Indexed: 11/23/2022]
Abstract
Phosphotyrosine (pTyr) signaling has evolved into a key cell-to-cell communication system. Activated receptor tyrosine kinases (RTKs) initiate several pTyr-dependent signaling networks by creating the docking sites required for the assembly of protein complexes. However, the mechanisms leading to network disassembly and its consequence on signal transduction remain essentially unknown. We show that activated RTKs terminate downstream signaling via the direct phosphorylation of an evolutionarily conserved Tyr present in most SRC homology (SH) 3 domains, which are often part of key hub proteins for RTK-dependent signaling. We demonstrate that the direct EPHA4 RTK phosphorylation of adaptor protein NCK SH3s at these sites results in the collapse of signaling networks and abrogates their function. We also reveal that this negative regulation mechanism is shared by other RTKs. Our findings uncover a conserved mechanism through which RTKs rapidly and reversibly terminate downstream signaling while remaining in a catalytically active state on the plasma membrane.
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Affiliation(s)
- Ugo Dionne
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - François J M Chartier
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Yossef López de Los Santos
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; INRS-Institut Armand-Frappier, Université du Québec, Laval, QC, Canada
| | - Noémie Lavoie
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - David N Bernard
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; INRS-Institut Armand-Frappier, Université du Québec, Laval, QC, Canada
| | - Sara L Banerjee
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - François Otis
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Département de Chimie, Université Laval, Québec, QC, Canada
| | - Kévin Jacquet
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Michel G Tremblay
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada
| | - Mani Jain
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Département de Biologie, Département de Biochimie, Microbiologie et Bio-informatique and Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Sylvie Bourassa
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada
| | - Gerald D Gish
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Joseph and Wolf Lebovic Health Complex, Toronto, ON, Canada
| | - Jean-Philippe Gagné
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Guy G Poirier
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Université Laval, Québec, QC, Canada
| | - Patrick Laprise
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Université Laval, Québec, QC, Canada
| | - Normand Voyer
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Département de Chimie, Université Laval, Québec, QC, Canada
| | - Christian R Landry
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Département de Biologie, Département de Biochimie, Microbiologie et Bio-informatique and Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Nicolas Doucet
- PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; INRS-Institut Armand-Frappier, Université du Québec, Laval, QC, Canada
| | - Nicolas Bisson
- Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec, QC, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Université Laval, Québec, QC, Canada.
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17
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NEDD9 stimulated MMP9 secretion is required for invadopodia formation in oral squamous cell carcinoma. Oncotarget 2018; 9:25503-25516. [PMID: 29876004 PMCID: PMC5986644 DOI: 10.18632/oncotarget.25347] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/24/2018] [Indexed: 12/19/2022] Open
Abstract
Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a component of the metastatic signatures of melanoma, breast cancer, glioblastoma, lung cancer and head and neck squamous cell carcinoma (HNSCC). Here we tested the efficacy of NEDD9's domains in stimulating matrix metalloproteinase (MMP) secretion and invadopodia formation in cells stably expressing various NEDD9 mutants. Replacement of the 13 YxxP motif substrate domain (SD) tyrosines and the C-terminal Y629 with phenylalanines (F14NEDD9) eliminated tyrosine phosphorylation, MMP9 secretion and loss of invadopodia formation. Mutation of the N-terminal SH3 domain Y12 to glutamic acid (Y12ENEDD9) or phenylalanine (Y12FNEDD9) reduced MMP9 secretion and inhibited invadopodia formation. SH3 domain deletion (∆SH3NEDD9) resulted in the loss of MMP9 secretion and a lack of invadopodia formation. The SH3–SD domain (SSNEDD9) construct exhibited tyrosine phosphorylation and stimulated MMP9 secretion, as did ∆CTNEDD9 which lacked the C-terminus (∆C-terminal; ∆CT). E13NEDD9 expression blocked MMP9 secretion and invadopodia formation. MICAL1 (molecule interacting with Cas-L1) silencing with a short hairpin RNA reduced MMP9 secretion, vimentin and E-cadherin levels while increasing N-cadherin and Rab6 levels, consistent with reduced invasive behavior. These findings indicate that NEDD9 SD phosphorylation and SH3 domain interactions are necessary for increasing MMP9 secretion and invadopodia formation.
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18
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Gemperle J, Hexnerová R, Lepšík M, Tesina P, Dibus M, Novotný M, Brábek J, Veverka V, Rosel D. Structural characterization of CAS SH3 domain selectivity and regulation reveals new CAS interaction partners. Sci Rep 2017; 7:8057. [PMID: 28808245 PMCID: PMC5556061 DOI: 10.1038/s41598-017-08303-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022] Open
Abstract
CAS is a docking protein downstream of the proto-oncogene Src with a role in invasion and metastasis of cancer cells. The CAS SH3 domain is indispensable for CAS-mediated signaling, but structural aspects of CAS SH3 ligand binding and regulation are not well understood. Here, we identified the consensus CAS SH3 binding motif and structurally characterized the CAS SH3 domain in complex with ligand. We revealed the requirement for an uncommon centrally localized lysine residue at position +2 of CAS SH3 ligands and two rather dissimilar optional anchoring residues, leucine and arginine, at position +5. We further expanded the knowledge of CAS SH3 ligand binding regulation by manipulating tyrosine 12 phosphorylation and confirmed the negative role of this phosphorylation on CAS SH3 ligand binding. Finally, by exploiting the newly identified binding requirements of the CAS SH3 domain, we predicted and experimentally verified two novel CAS SH3 binding partners, DOK7 and GLIS2.
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Affiliation(s)
- Jakub Gemperle
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague, Czech Republic
| | - Rozálie Hexnerová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2, Prague, Czech Republic
| | - Martin Lepšík
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2, Prague, Czech Republic
| | - Petr Tesina
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2, Prague, Czech Republic
| | - Michal Dibus
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague, Czech Republic
| | - Marian Novotný
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague, Czech Republic
| | - Jan Brábek
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague, Czech Republic
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2, Prague, Czech Republic.
| | - Daniel Rosel
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague, Czech Republic.
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19
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Panizza E, Branca RMM, Oliviusson P, Orre LM, Lehtiö J. Isoelectric point-based fractionation by HiRIEF coupled to LC-MS allows for in-depth quantitative analysis of the phosphoproteome. Sci Rep 2017; 7:4513. [PMID: 28674419 PMCID: PMC5495806 DOI: 10.1038/s41598-017-04798-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 04/13/2017] [Indexed: 02/06/2023] Open
Abstract
Protein phosphorylation is involved in the regulation of most eukaryotic cells functions and mass spectrometry-based analysis has made major contributions to our understanding of this regulation. However, low abundance of phosphorylated species presents a major challenge in achieving comprehensive phosphoproteome coverage and robust quantification. In this study, we developed a workflow employing titanium dioxide phospho-enrichment coupled with isobaric labeling by Tandem Mass Tags (TMT) and high-resolution isoelectric focusing (HiRIEF) fractionation to perform in-depth quantitative phosphoproteomics starting with a low sample quantity. To benchmark the workflow, we analyzed HeLa cells upon pervanadate treatment or cell cycle arrest in mitosis. Analyzing 300 µg of peptides per sample, we identified 22,712 phosphorylation sites, of which 19,075 were localized with high confidence and 1,203 are phosphorylated tyrosine residues, representing 6.3% of all detected phospho-sites. HiRIEF fractions with the most acidic isoelectric points are enriched in multiply phosphorylated peptides, which represent 18% of all the phospho-peptides detected in the pH range 2.5–3.7. Cross-referencing with the PhosphoSitePlus database reveals 1,264 phosphorylation sites that have not been previously reported and kinase association analysis suggests that a subset of these may be functional during the mitotic phase.
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Affiliation(s)
- Elena Panizza
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Rui M M Branca
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | | | - Lukas M Orre
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Janne Lehtiö
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden.
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20
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The role of focal adhesion anchoring domains of CAS in mechanotransduction. Sci Rep 2017; 7:46233. [PMID: 28406229 PMCID: PMC5390273 DOI: 10.1038/srep46233] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/14/2017] [Indexed: 11/08/2022] Open
Abstract
CAS is a docking protein, which was shown to act as a mechanosensor in focal adhesions. The unique assembly of structural domains in CAS is important for its function as a mechanosensor. The tension within focal adhesions is transmitted to a stretchable substrate domain of CAS by focal adhesion-targeting of SH3 and CCH domain of CAS, which anchor the CAS protein in focal adhesions. Mechanistic models of the stretching biosensor propose equal roles for both anchoring domains. Using deletion mutants and domain replacements, we have analyzed the relative importance of the focal adhesion anchoring domains on CAS localization and dynamics in focal adhesions as well as on CAS-mediated mechanotransduction. We confirmed the predicted prerequisite of the focal adhesion targeting for CAS-dependent mechanosensing and unraveled the critical importance of CAS SH3 domain in mechanosensing. We further show that CAS localizes to the force transduction layer of focal adhesions and that mechanical stress stabilizes CAS in focal adhesions.
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21
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Zitterbart R, Seitz O. Parallele chemische Proteinsynthese auf der Oberfläche zur schnellen Analyse der Phosphoregulierung von SH3-Domänen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601843] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Robert Zitterbart
- Institut für Chemie; Humboldt-Universität zu Berlin; Brook-Taylor-Straße 2 12489 Berlin Deutschland
| | - Oliver Seitz
- Institut für Chemie; Humboldt-Universität zu Berlin; Brook-Taylor-Straße 2 12489 Berlin Deutschland
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22
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Zitterbart R, Seitz O. Parallel Chemical Protein Synthesis on a Surface Enables the Rapid Analysis of the Phosphoregulation of SH3 Domains. Angew Chem Int Ed Engl 2016; 55:7252-6. [DOI: 10.1002/anie.201601843] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Robert Zitterbart
- Institut für Chemie; Humboldt-Universität zu Berlin; Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - Oliver Seitz
- Institut für Chemie; Humboldt-Universität zu Berlin; Brook-Taylor-Strasse 2 12489 Berlin Germany
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23
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Holehouse AS, Naegle KM. Reproducible Analysis of Post-Translational Modifications in Proteomes--Application to Human Mutations. PLoS One 2015; 10:e0144692. [PMID: 26659599 PMCID: PMC4685989 DOI: 10.1371/journal.pone.0144692] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/23/2015] [Indexed: 01/19/2023] Open
Abstract
Background Protein post-translational modifications (PTMs) are an important aspect of protein regulation. The number of PTMs discovered within the human proteome, and other proteomes, has been rapidly expanding in recent years. As a consequence of the rate in which new PTMs are identified, analysis done in one year may result in different conclusions when repeated in subsequent years. Among the various functional questions pertaining to PTMs, one important relationship to address is the interplay between modifications and mutations. Specifically, because the linear sequence surrounding a modification site often determines molecular recognition, it is hypothesized that mutations near sites of PTMs may be more likely to result in a detrimental effect on protein function, resulting in the development of disease. Methods and Results We wrote an application programming interface (API) to make analysis of ProteomeScout, a comprehensive database of PTMs and protein information, easy and reproducible. We used this API to analyze the relationship between PTMs and human mutations associated with disease (based on the ‘Clinical Significance’ annotation from dbSNP). Proteins containing pathogenic mutations demonstrated a significant study bias which was controlled for by analyzing only well-studied proteins, based on their having at least one pathogenic mutation. We found that pathogenic mutations are significantly more likely to lie within eight amino acids of a phosphoserine, phosphotyrosine or ubiquitination site when compared to mutations in general, based on a Fisher’s Exact test. Despite the skew of pathogenic mutations occurring on positively charged arginines, we could not account for this relationship based only on residue type. Finally, we hypothesize a potential mechanism for a pathogenic mutation on RAF1, based on its proximity to a phosphorylation site, which represents a subtle regulation difference that may explain why its biochemical effect has failed to be uncovered previously. The combination of the API and a dynamically expanding PTM database will make the reanalysis of this question and other systems-level questions easier in the future.
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Affiliation(s)
- Alex S Holehouse
- Division of Biology and Biomedical Sciences, Washington University, St. Louis, MO, United States of America
- The Center for Biological Systems Engineering, Washington University, St. Louis, MO, United States of America
| | - Kristen M Naegle
- The Center for Biological Systems Engineering, Washington University, St. Louis, MO, United States of America
- Biomedical Engineering, Washington University, St. Louis, MO, United States of America
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Drobek A, Kralova J, Skopcova T, Kucova M, Novák P, Angelisová P, Otahal P, Alberich-Jorda M, Brdicka T. PSTPIP2, a Protein Associated with Autoinflammatory Disease, Interacts with Inhibitory Enzymes SHIP1 and Csk. THE JOURNAL OF IMMUNOLOGY 2015; 195:3416-26. [PMID: 26304991 DOI: 10.4049/jimmunol.1401494] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 07/28/2015] [Indexed: 11/19/2022]
Abstract
Mutations in the adaptor protein PSTPIP2 are the cause of the autoinflammatory disease chronic multifocal osteomyelitis in mice. This disease closely resembles the human disorder chronic recurrent multifocal osteomyelitis, characterized by sterile inflammation of the bones and often associated with inflammation in other organs, such as the skin. The most critical process in the disease's development is the enhanced production of IL-1β. This excessive IL-1β is likely produced by neutrophils. In addition, the increased activity of macrophages, osteoclasts, and megakaryocytes has also been described. However, the molecular mechanism of how PSTPIP2 deficiency results in this phenotype is poorly understood. Part of the PSTPIP2 inhibitory function is mediated by protein tyrosine phosphatases from the proline-, glutamic acid-, serine- and threonine-rich (PEST) family, which are known to interact with the central part of this protein, but other regions of PSTPIP2 not required for PEST-family phosphatase binding were also shown to be indispensable for PSTPIP2 function. In this article, we show that PSTPIP2 binds the inhibitory enzymes Csk and SHIP1. The interaction with SHIP1 is of particular importance because it binds to the critical tyrosine residues at the C terminus of PSTPIP2, which is known to be crucial for its PEST-phosphatase-independent inhibitory effects in different cellular systems. We demonstrate that in neutrophils this region is important for the PSTPIP2-mediated suppression of IL-1β processing and that SHIP1 inhibition results in the enhancement of this processing. We also describe deregulated neutrophil response to multiple activators, including silica, Ab aggregates, and LPS, which is suggestive of a rather generalized hypersensitivity of these cells to various external stimulants.
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Affiliation(s)
- Ales Drobek
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Jarmila Kralova
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Tereza Skopcova
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Marketa Kucova
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Petr Novák
- Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Pavla Angelisová
- Laboratory of Molecular Immunology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic; and
| | - Pavel Otahal
- Laboratory of Molecular Immunology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic; and
| | - Meritxell Alberich-Jorda
- Laboratory of Hemato-oncology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Tomas Brdicka
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic;
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25
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Iqbal Z, Hoessli DC, Qazi WM, Ahmad M, Shakoori AR, Nasir-ud-Din. Exploring the sequence context of phosphorylatable amino acids: the contribution of the upgraded MAPRes tool. J Cell Biochem 2014; 116:370-9. [PMID: 25258092 DOI: 10.1002/jcb.24983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/19/2014] [Indexed: 11/10/2022]
Abstract
Several models that predict where post-translational modifications are likely to occur and formulate the corresponding association rules are available to analyze the functional potential of a protein sequence, but an algorithm incorporating the functional groups of the involved amino acids in the sequence analyses process is not yet available. In its previous version, MAPRes was utilized to investigate the influence of the surrounding amino acids of post- translationally and co-translationally modifiable sites. The MAPRes has been upgraded to take into account the different biophysical and biochemical properties of the amino acids that have the potential to influence different post- translational modifications (PTMs). In the present study, the upgraded version of MAPRes was implemented on phosphorylated Ser/Thr/Tyr data by considering the polarity and charge of the surrounding amino acids. The patterns mined by MAPRes incorporating structural information on polarity and charge of amino acids suggest distinct structure-function relationships for phosphorylated serines in a multifunctional protein such as the insulin-receptor substrate-1 (IRS-1) protein. The new version of MAPRes is freely available at http://www.imsb.edu.pk/Database.htm.
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Affiliation(s)
- Zeeshan Iqbal
- Institute of Molecular Sciences and Bioinformatics, Lahore, Pakistan
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26
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CAS directly interacts with vinculin to control mechanosensing and focal adhesion dynamics. Cell Mol Life Sci 2013; 71:727-44. [PMID: 23974298 PMCID: PMC3901934 DOI: 10.1007/s00018-013-1450-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/19/2013] [Accepted: 08/05/2013] [Indexed: 12/31/2022]
Abstract
Focal adhesions are cellular structures through which both mechanical forces and regulatory signals are transmitted. Two focal adhesion-associated proteins, Crk-associated substrate (CAS) and vinculin, were both independently shown to be crucial for the ability of cells to transmit mechanical forces and to regulate cytoskeletal tension. Here, we identify a novel, direct binding interaction between CAS and vinculin. This interaction is mediated by the CAS SRC homology 3 domain and a proline-rich sequence in the hinge region of vinculin. We show that CAS localization in focal adhesions is partially dependent on vinculin, and that CAS–vinculin coupling is required for stretch-induced activation of CAS at the Y410 phosphorylation site. Moreover, CAS–vinculin binding significantly affects the dynamics of CAS and vinculin within focal adhesions as well as the size of focal adhesions. Finally, disruption of CAS binding to vinculin reduces cell stiffness and traction force generation. Taken together, these findings strongly implicate a crucial role of CAS–vinculin interaction in mechanosensing and focal adhesion dynamics.
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27
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Xiao X, Mruk DD, Cheng CY. c-Yes regulates cell adhesion at the apical ectoplasmic specialization-blood-testis barrier axis via its effects on protein recruitment and distribution. Am J Physiol Endocrinol Metab 2013; 304:E145-59. [PMID: 23169788 PMCID: PMC3543571 DOI: 10.1152/ajpendo.00422.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
During spermatogenesis, extensive restructuring takes place at the cell-cell interface since developing germ cells migrate progressively from the basal to the adluminal compartment of the seminiferous epithelium. Since germ cells per se are not motile cells, their movement relies almost exclusively on the Sertoli cell. Nonetheless, extensive exchanges in signaling take place between these cells in the seminiferous epithelium. c-Yes, a nonreceptor protein tyrosine kinase belonging to the Src family kinases (SFKs) and a crucial signaling protein, was recently shown to be upregulated at the Sertoli cell-cell interface at the blood-testis barrier (BTB) at stages VIII-IX of the seminiferous epithelial cycle of spermatogenesis. It was also highly expressed at the Sertoli cell-spermatid interface known as apical ectoplasmic specialization (apical ES) at stage V to early stage VIII of the epithelial cycle during spermiogenesis. Herein, it was shown that the knockdown of c-Yes by RNAi in vitro and in vivo affected both Sertoli cell adhesion at the BTB and spermatid adhesion at the apical ES, causing a disruption of the Sertoli cell tight junction-permeability barrier function, germ cell loss from the seminiferous epithelium, and also a loss of spermatid polarity. These effects were shown to be mediated by changes in distribution and/or localization of adhesion proteins at the BTB (e.g., occludin, N-cadherin) and at the apical ES (e.g., nectin-3) and possibly the result of changes in the underlying actin filaments at the BTB and the apical ES. These findings implicate that c-Yes is a likely target of male contraceptive research.
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Affiliation(s)
- Xiang Xiao
- Center for Biomedical Research, Population Council, New York, NY 10065, USA
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28
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Pesti S, Balázs A, Udupa R, Szabó B, Fekete A, Bőgel G, Buday L. Complex formation of EphB1/Nck/Caskin1 leads to tyrosine phosphorylation and structural changes of the Caskin1 SH3 domain. Cell Commun Signal 2012. [PMID: 23181695 PMCID: PMC3549760 DOI: 10.1186/1478-811x-10-36] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Scaffold proteins have an important role in the regulation of signal propagation. These proteins do not possess any enzymatic activity but can contribute to the formation of multiprotein complexes. Although scaffold proteins are present in all cell types, the nervous system contains them in the largest amount. Caskin proteins are typically present in neuronal cells, particularly, in the synapses. However, the signaling mechanisms by which Caskin proteins are regulated are largely unknown. Results Here we demonstrate that EphB1 receptor tyrosine kinase can recruit Caskin1 through the adaptor protein Nck. Upon activation of the receptor kinase, the SH2 domain of Nck binds to one of its tyrosine residues, while Nck SH3 domains interact with the proline-rich domain of Caskin1. Complex formation of the receptor, adaptor and scaffold proteins results in the tyrosine phosphorylation of Caskin1 on its SH3 domain. The phosphorylation sites were identified by mass-spectrometry as tyrosines 296 and 336. To reveal the structural consequence of this phosphorylation, CD spectroscopy was performed. This measurement suggests that upon tyrosine phosphorylation the structure of the Caskin1 SH3 domain changes significantly. Conclusion Taken together, we propose that the scaffold protein Caskin1 can form a complex with the EphB1 tyrosine kinase via the Nck protein as a linker. Complex formation results in tyrosine phosphorylation of the Caskin1 SH3 domain. Although we were not able to identify any physiological partner of the SH3 domain so far, we could demonstrate that phosphorylation on conserved tyrosine residues results in marked changes in the structure of the SH3 domain.
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Affiliation(s)
- Szabolcs Pesti
- From the Department of Medical Chemistry, Semmelweis University Medical School, Budapest, 1094, Hungary.
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