1
|
Stark K, Crowe O, Lewellyn L. Precise levels of the Drosophila adaptor protein Dreadlocks maintain the size and stability of germline ring canals. J Cell Sci 2021; 134:238107. [PMID: 33912915 PMCID: PMC8106954 DOI: 10.1242/jcs.254730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/15/2021] [Indexed: 01/24/2023] Open
Abstract
Intercellular bridges are essential for fertility in many organisms. The developing fruit fly egg has become the premier model system to study intercellular bridges. During oogenesis, the oocyte is connected to supporting nurse cells by relatively large intercellular bridges, or ring canals. Once formed, the ring canals undergo a 20-fold increase in diameter to support the movement of materials from the nurse cells to the oocyte. Here, we demonstrate a novel role for the conserved SH2/SH3 adaptor protein Dreadlocks (Dock) in regulating ring canal size and structural stability in the germline. Dock localizes at germline ring canals throughout oogenesis. Loss of Dock leads to a significant reduction in ring canal diameter, and overexpression of Dock causes dramatic defects in ring canal structure and nurse cell multinucleation. The SH2 domain of Dock is required for ring canal localization downstream of Src64 (also known as Src64B), and the function of one or more of the SH3 domains is necessary for the strong overexpression phenotype. Genetic interaction and localization studies suggest that Dock promotes WASp-mediated Arp2/3 activation in order to determine ring canal size and regulate growth. This article has an associated First Person interview with the first author of the paper. Summary:Drosophila Dock likely functions downstream of WASp and the Arp2/3 complex to regulate the size and stability of the germline ring canals in the developing egg chamber.
Collapse
Affiliation(s)
- Kara Stark
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Olivia Crowe
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Lindsay Lewellyn
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| |
Collapse
|
2
|
Wnt6 regulates the homeostasis of the stem cell niche via Rac1-and Cdc42-mediated noncanonical Wnt signalling pathways in Drosophila testis. Exp Cell Res 2021; 402:112511. [PMID: 33582096 DOI: 10.1016/j.yexcr.2021.112511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 11/23/2022]
Abstract
The homeostasis of the stem cell niche is regulated by both intrinsic and extrinsic factors, and the complex and ordered molecular and cellular regulatory mechanisms need to be further explored. In Drosophila testis, germline stem cells (GSCs) rely on hub cells for self-renewal and physical attachment. GSCs are also in contact with somatic cyst stem cells (CySCs). Utilizing genetic manipulation in Drosophila, we investigated the role of Wnt6 in vivo and in vitro. In Drosophila testis, we found that Wnt6 is required for GSC differentiation and CySC self-renewal. In Schneider 2 (S2) cells, we found that Wnt6 regulates cell proliferation and apoptosis. Mechanistically, we demonstrated that Wnt6 can downregulate the expression levels of Arm, Rac1 and Cdc42 in S2 cells. Notably, Rac1 and Cdc42, which act downstream of the noncanonical Wnt signalling pathway, imitated the phenotypes of Wnt6 in Drosophila testis. Thus, the newly discovered Wnt6-Rac1/Cdc42 signal axis is required for the homeostasis of the stem cell niche in the Drosophila testis.
Collapse
|
3
|
Gao J, Zhao L, Luo Q, Liu S, Lin Z, Wang P, Fu X, Chen J, Zhang H, Lin L, Shi A. An EHBP-1-SID-3-DYN-1 axis promotes membranous tubule fission during endocytic recycling. PLoS Genet 2020; 16:e1008763. [PMID: 32384077 PMCID: PMC7239482 DOI: 10.1371/journal.pgen.1008763] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 05/20/2020] [Accepted: 04/07/2020] [Indexed: 12/16/2022] Open
Abstract
The ACK family tyrosine kinase SID-3 is involved in the endocytic uptake of double-stranded RNA. Here we identified SID-3 as a previously unappreciated recycling regulator in the Caenorhabditis elegans intestine. The RAB-10 effector EHBP-1 is required for the endosomal localization of SID-3. Accordingly, animals with loss of SID-3 phenocopied the recycling defects observed in ehbp-1 and rab-10 single mutants. Moreover, we detected sequential protein interactions between EHBP-1, SID-3, NCK-1, and DYN-1. In the absence of SID-3, DYN-1 failed to localize at tubular recycling endosomes, and membrane tubules breaking away from endosomes were mostly absent, suggesting that SID-3 acts synergistically with the downstream DYN-1 to promote endosomal tubule fission. In agreement with these observations, overexpression of DYN-1 significantly increased recycling transport in SID-3-deficient cells. Finally, we noticed that loss of RAB-10 or EHBP-1 compromised feeding RNAi efficiency in multiple tissues, implicating basolateral recycling in the transport of RNA silencing signals. Taken together, our study demonstrated that in C. elegans intestinal epithelia, SID-3 acts downstream of EHBP-1 to direct fission of recycling endosomal tubules in concert with NCK-1 and DYN-1. After endocytic uptake, a recycling transport system is deployed to deliver endocytosed macromolecules, fluid, membranes, and membrane proteins back to the cell surface. This process is essential for a series of biological processes such as cytokinesis, cell migration, maintenance of cell polarity, and synaptic plasticity. Recycling endosomes mainly consist of membrane tubules and often undergo membrane fission to generate vesicular carriers, which mediates the delivery of cargo proteins back to the plasma membrane. Previous studies suggested that RAB-10 and its effector protein EHBP-1 function jointly to generate and maintain recycling endosomal tubules. However, the mechanism coupling recycling endosomal tubulation and membrane fission remains elusive. Here, we identified SID-3 as a new interactor of EHBP-1. EHBP-1 is required for the endosomal localization of SID-3 and initiates a protein interaction cascade involving SID-3, NCK-1, and DYN-1/dynamin. We also found that SID-3 functions downstream of EHBP-1 to encourage membrane scission, and that ectopic expression of DYN-1 improves recycling transport in SID-3-depleted cells. Our findings revealed EHBP-1 as a point of convergence between RAB-10-mediated endosomal tubulation and SID-3-assisted membrane tubule fission during endocytic recycling.
Collapse
Affiliation(s)
- Jinghu Gao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Linyue Zhao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qian Luo
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shuyao Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ziyang Lin
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Peixiang Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xin Fu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Juan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hongjie Zhang
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau SAR, China
| | - Long Lin
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- * E-mail: (LL); (AS)
| | - Anbing Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Key Laboratory of Neurological Disease of National Education Ministry, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- * E-mail: (LL); (AS)
| |
Collapse
|
4
|
The non-receptor tyrosine kinase ACK: regulatory mechanisms, signalling pathways and opportunities for attACKing cancer. Biochem Soc Trans 2020; 47:1715-1731. [PMID: 31845724 DOI: 10.1042/bst20190176] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/30/2019] [Accepted: 12/03/2019] [Indexed: 12/16/2022]
Abstract
Activated Cdc42-associated kinase or ACK, is a non-receptor tyrosine kinase and an effector protein for the small G protein Cdc42. A substantial body of evidence has accumulated in the past few years heavily implicating ACK as a driver of oncogenic processes. Concomitantly, more is also being revealed regarding the signalling pathways involving ACK and molecular details of its modes of action. Some details are also available regarding the regulatory mechanisms of this kinase, including activation and regulation of its catalytic activity, however, a full understanding of these aspects remains elusive. This review considers the current knowledge base concerning ACK and summarizes efforts and future prospects to target ACK therapeutically in cancer.
Collapse
|
5
|
Jacquet K, Banerjee SL, Chartier FJM, Elowe S, Bisson N. Proteomic Analysis of NCK1/2 Adaptors Uncovers Paralog-specific Interactions That Reveal a New Role for NCK2 in Cell Abscission During Cytokinesis. Mol Cell Proteomics 2018; 17:1979-1990. [PMID: 30002203 DOI: 10.1074/mcp.ra118.000689] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 07/11/2018] [Indexed: 12/31/2022] Open
Abstract
Signals from cell surface receptors are often relayed via adaptor proteins. NCK1 and NCK2 are Src-Homology (SH) 2 and 3 domain adaptors that regulate processes requiring a remodeling of the actin cytoskeleton. Evidence from gene inactivation in mouse suggests that NCK1 and NCK2 are functionally redundant, although recent reports support the idea of unique functions for NCK1 and NCK2. We sought to examine this question further by delineating NCK1- and NCK2-specific signaling networks. We used both affinity purification-mass spectrometry and BioID proximity labeling to identify NCK1/2 signaling networks comprised of 98 proteins. Strikingly, we found 30 proteins restricted to NCK1 and 28 proteins specifically associated with NCK2, suggesting differences in their function. We report that Nck2 -/-, but not Nck1 -/- mouse embryo fibroblasts (MEFs) are multinucleated and display extended protrusions reminiscent of intercellular bridges, which correlate with an extended time spent in cytokinesis as well as a failure of a significant proportion of cells to complete abscission. Our data also show that the midbody of NCK2-deficient cells is not only increased in length, but also altered in composition, as judged by the mislocalization of AURKB, PLK1 and ECT2. Finally, we show that NCK2 function during cytokinesis requires its SH2 domain. Taken together, our data delineate the first high-confidence interactome for NCK1/2 adaptors and highlight several proteins specifically associated with either protein. Thus, contrary to what is generally accepted, we demonstrate that NCK1 and NCK2 are not completely redundant, and shed light on a previously uncharacterized function for the NCK2 adaptor protein in cell division.
Collapse
Affiliation(s)
- Kévin Jacquet
- From the ‡Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec G1R 2J6, QC, Canada.,§Centre de recherche sur le cancer de l'Université Laval, Québec G1R 2J6, QC, Canada.,¶PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec G1V 0A6, QC, Canada
| | - Sara L Banerjee
- From the ‡Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec G1R 2J6, QC, Canada.,§Centre de recherche sur le cancer de l'Université Laval, Québec G1R 2J6, QC, Canada.,¶PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec G1V 0A6, QC, Canada
| | - François J M Chartier
- From the ‡Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec G1R 2J6, QC, Canada.,§Centre de recherche sur le cancer de l'Université Laval, Québec G1R 2J6, QC, Canada.,¶PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec G1V 0A6, QC, Canada
| | - Sabine Elowe
- §Centre de recherche sur le cancer de l'Université Laval, Québec G1R 2J6, QC, Canada.,¶PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec G1V 0A6, QC, Canada.,‖Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Reproduction, santé de la mère et de l'enfant, Québec G1V 4G2, QC, Canada.,**Department of Pediatrics, Université Laval, Québec, QC, Canada
| | - Nicolas Bisson
- From the ‡Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Oncologie, Québec G1R 2J6, QC, Canada; .,§Centre de recherche sur le cancer de l'Université Laval, Québec G1R 2J6, QC, Canada.,¶PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec G1V 0A6, QC, Canada.,‡‡Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Québec G1V 0A6, QC, Canada
| |
Collapse
|
6
|
Hu L, Xu J, Yin MX, Zhang L, Lu Y, Wu W, Xue Z, Ho MS, Gao G, Zhao Y, Zhang L. Ack promotes tissue growth via phosphorylation and suppression of the Hippo pathway component Expanded. Cell Discov 2016; 2:15047. [PMID: 27462444 PMCID: PMC4860957 DOI: 10.1038/celldisc.2015.47] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 12/01/2015] [Indexed: 12/11/2022] Open
Abstract
Non-receptor tyrosine kinase activated cdc42 kinase was reported to participate in several types of cancers in mammals. It is also believed to have an anti-apoptotic function in Drosophila. Here, we report the identification of Drosophila activated cdc42 kinase as a growth promoter and a novel Hippo signaling pathway regulator. We find that activated cdc42 kinase promotes tissue growth through modulating Yorkie activity. Furthermore, we demonstrate that activated cdc42 kinase interacts with Expanded and induces tyrosine phosphorylation of Expanded on multiple sites. We propose a model that activated cdc42 kinase negatively regulates Expanded by changing its phosphorylation status to promote tissue growth. Moreover, we show that ack genetically interacts with merlin and expanded. Thus, we identify Drosophila activated cdc42 kinase as a Hippo pathway regulator.
Collapse
Affiliation(s)
- Lianxin Hu
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Jiajun Xu
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Meng-Xin Yin
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Liguo Zhang
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign , Urbana, IL, USA
| | - Yi Lu
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Wenqing Wu
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China
| | - Zhaoyu Xue
- School of Life Sciences, Tsinghua University , Beijing, China
| | - Margaret S Ho
- Department of Anatomy and Neurobiology, School of Medicine, Tongji University , Shanghai, China
| | - Guanjun Gao
- School of Life Sciences, Tsinghua University , Beijing, China
| | - Yun Zhao
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Lei Zhang
- State Key Laboratory of Cell Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| |
Collapse
|
7
|
Basiri ML, Ha A, Chadha A, Clark NM, Polyanovsky A, Cook B, Avidor-Reiss T. A migrating ciliary gate compartmentalizes the site of axoneme assembly in Drosophila spermatids. Curr Biol 2014; 24:2622-31. [PMID: 25447994 DOI: 10.1016/j.cub.2014.09.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/27/2014] [Accepted: 09/16/2014] [Indexed: 01/07/2023]
Abstract
BACKGROUND In most cells, the cilium is formed within a compartment separated from the cytoplasm. Entry into the ciliary compartment is regulated by a specialized gate located at the base of the cilium in a region known as the transition zone. The transition zone is closely associated with multiple structures of the ciliary base, including the centriole, axoneme, and ciliary membrane. However, the contribution of these structures to the ciliary gate remains unclear. RESULTS Here we report that, in Drosophila spermatids, a conserved module of transition zone proteins mutated in Meckel-Gruber syndrome (MKS), including Cep290, Mks1, B9d1, and B9d2, comprise a ciliary gate that continuously migrates away from the centriole to compartmentalize the growing axoneme tip. We show that Cep290 is essential for transition zone composition, compartmentalization of the axoneme tip, and axoneme integrity and find that MKS proteins also delimit a centriole-independent compartment in mouse spermatids. CONCLUSIONS Our findings demonstrate that the ciliary gate can migrate away from the base of the cilium, thereby functioning independently of the centriole and of a static interaction with the axoneme to compartmentalize the site of axoneme assembly.
Collapse
Affiliation(s)
- Marcus L Basiri
- Department of Biological Sciences, University of Toledo, 3050 W. Towerview Boulevard, Toledo, OH 43606, USA
| | - Andrew Ha
- Department of Biological Sciences, University of Toledo, 3050 W. Towerview Boulevard, Toledo, OH 43606, USA
| | - Abhishek Chadha
- Department of Cell Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nicole M Clark
- Department of Biological Sciences, University of Toledo, 3050 W. Towerview Boulevard, Toledo, OH 43606, USA
| | - Andrey Polyanovsky
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Prospekt Toreza, 44, 194223 St. Petersburg, Russia
| | - Boaz Cook
- Department of Cell Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Tomer Avidor-Reiss
- Department of Biological Sciences, University of Toledo, 3050 W. Towerview Boulevard, Toledo, OH 43606, USA.
| |
Collapse
|
8
|
Strochlic TI, Stavrides KP, Thomas SV, Nicolas E, O'Reilly AM, Peterson JR. Ack kinase regulates CTP synthase filaments during Drosophila oogenesis. EMBO Rep 2014; 15:1184-91. [PMID: 25223282 DOI: 10.15252/embr.201438688] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The enzyme CTP synthase (CTPS) dynamically assembles into macromolecular filaments in bacteria, yeast, Drosophila, and mammalian cells, but the role of this morphological reorganization in regulating CTPS activity is controversial. During Drosophila oogenesis, CTPS filaments are transiently apparent in ovarian germline cells during a period of intense genomic endoreplication and stockpiling of ribosomal RNA. Here, we demonstrate that CTPS filaments are catalytically active and that their assembly is regulated by the non-receptor tyrosine kinase DAck, the Drosophila homologue of mammalian Ack1 (activated cdc42-associated kinase 1), which we find also localizes to CTPS filaments. Egg chambers from flies deficient in DAck or lacking DAck catalytic activity exhibit disrupted CTPS filament architecture and morphological defects that correlate with reduced fertility. Furthermore, ovaries from these flies exhibit reduced levels of total RNA, suggesting that DAck may regulate CTP synthase activity. These findings highlight an unexpected function for DAck and provide insight into a novel pathway for the developmental control of an essential metabolic pathway governing nucleotide biosynthesis.
Collapse
Affiliation(s)
- Todd I Strochlic
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Kevin P Stavrides
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, USA Epigenetics and Progenitor Cells Keystone Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Sam V Thomas
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | | | - Alana M O'Reilly
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, USA Epigenetics and Progenitor Cells Keystone Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | | |
Collapse
|
9
|
Src kinase function controls progenitor cell pools during regeneration and tumor onset in the Drosophila intestine. Oncogene 2014; 34:2371-84. [DOI: 10.1038/onc.2014.163] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 03/28/2014] [Accepted: 03/29/2014] [Indexed: 12/11/2022]
|
10
|
GOLPH3 is essential for contractile ring formation and Rab11 localization to the cleavage site during cytokinesis in Drosophila melanogaster. PLoS Genet 2014; 10:e1004305. [PMID: 24786584 PMCID: PMC4006750 DOI: 10.1371/journal.pgen.1004305] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 02/28/2014] [Indexed: 01/02/2023] Open
Abstract
The highly conserved Golgi phosphoprotein 3 (GOLPH3) protein has been described as a Phosphatidylinositol 4-phosphate [PI(4)P] effector at the Golgi. GOLPH3 is also known as a potent oncogene, commonly amplified in several human tumors. However, the molecular pathways through which the oncoprotein GOLPH3 acts in malignant transformation are largely unknown. GOLPH3 has never been involved in cytokinesis. Here, we characterize the Drosophila melanogaster homologue of human GOLPH3 during cell division. We show that GOLPH3 accumulates at the cleavage furrow and is required for successful cytokinesis in Drosophila spermatocytes and larval neuroblasts. In premeiotic spermatocytes GOLPH3 protein is required for maintaining the organization of Golgi stacks. In dividing spermatocytes GOLPH3 is essential for both contractile ring and central spindle formation during cytokinesis. Wild type function of GOLPH3 enables maintenance of centralspindlin and Rho1 at cell equator and stabilization of Myosin II and Septin rings. We demonstrate that the molecular mechanism underlying GOLPH3 function in cytokinesis is strictly dependent on the ability of this protein to interact with PI(4)P. Mutations that abolish PI(4)P binding impair recruitment of GOLPH3 to both the Golgi and the cleavage furrow. Moreover telophase cells from mutants with defective GOLPH3-PI(4)P interaction fail to accumulate PI(4)P-and Rab11-associated secretory organelles at the cleavage site. Finally, we show that GOLPH3 protein interacts with components of both cytokinesis and membrane trafficking machineries in Drosophila cells. Based on these results we propose that GOLPH3 acts as a key molecule to coordinate phosphoinositide signaling with actomyosin dynamics and vesicle trafficking during cytokinesis. Because cytokinesis failures have been associated with premalignant disease and cancer, our studies suggest novel insight into molecular circuits involving the oncogene GOLPH3 in cytokinesis. In animal cell cytokinesis, constriction of an actomyosin ring at the equatorial cortex of dividing cells must be finely coordinated with plasma membrane remodeling and vesicle trafficking at the cleavage furrow. Accurate control of these events during cell cleavage is essential for maintaining ploidy and preventing neoplastic transformation. GOLPH3 has been recognized as a potent oncogene, involved in the development of several human tumors. However, the precise roles played by GOLPH3 in tumorigenesis are not yet understood. In this manuscript we demonstrate for the first time the requirement for GOLPH3 for cytokinesis. GOLPH3 protein localizes at the cleavage site of Drosophila dividing cells and is essential for cytokinesis in male meiotic cells and larval neuroblasts. We show that this protein acts as a key molecule in coupling plasma membrane remodeling with actomyosin ring assembly and stability during cytokinesis. Our studies indicate a novel connection between GOLPH3 and the molecular mechanisms of cytokinesis, opening new fields of investigation into the tumor cell biology of this oncogene.
Collapse
|