| Structural highlights
Function
[RGAP1_HUMAN] Component of the centralspindlin complex that serves as a microtubule-dependent and Rho-mediated signaling required for the myosin contractile ring formation during the cell cycle cytokinesis. Plays key roles in controlling cell growth and differentiation of hematopoietic cells through mechanisms other than regulating Rac GTPase activity. Also involved in the regulation of growth-related processes in adipocytes and myoblasts. May be involved in regulating spermatogenesis and in the RACGAP1 pathway in neuronal proliferation. Shows strong GAP (GTPase activation) activity towards CDC42 and RAC1 and less towards RHOA. Essential for the early stages of embryogenesis. May play a role in regulating cortical activity through RHOA during cytokinesis. May participate in the regulation of sulfate transport in male germ cells.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
Publication Abstract from PubMed
At the end of cell division, cytokinesis splits the cytoplasm of nascent daughter cells and partitions segregated sister genomes. To coordinate cell division with chromosome segregation, the mitotic spindle controls cytokinetic events at the cell envelope. The spindle midzone stimulates the actomyosin-driven contraction of the cleavage furrow, which proceeds until the formation of a microtubule-rich intercellular bridge with the midbody at its centre. The midbody directs the final membrane abscission reaction and has been proposed to attach the cleavage furrow to the intercellular bridge. How the mitotic spindle is connected to the plasma membrane during cytokinesis is not understood. Here we identify a plasma membrane tethering activity in the centralspindlin protein complex, a conserved component of the spindle midzone and midbody. We demonstrate that the C1 domain of the centralspindlin subunit MgcRacGAP associates with the plasma membrane by interacting with polyanionic phosphoinositide lipids. Using X-ray crystallography we determine the structure of this atypical C1 domain. Mutations in the hydrophobic cap and in basic residues of the C1 domain of MgcRacGAP prevent association of the protein with the plasma membrane, and abrogate cytokinesis in human and chicken cells. Artificial membrane tethering of centralspindlin restores cell division in the absence of the C1 domain of MgcRacGAP. Although C1 domain function is dispensable for the formation of the midzone and midbody, it promotes contractility and is required for the attachment of the plasma membrane to the midbody, a long-postulated function of this organelle. Our analysis suggests that centralspindlin links the mitotic spindle to the plasma membrane to secure the final cut during cytokinesis in animal cells.
Centralspindlin links the mitotic spindle to the plasma membrane during cytokinesis.,Lekomtsev S, Su KC, Pye VE, Blight K, Sundaramoorthy S, Takaki T, Collinson LM, Cherepanov P, Divecha N, Petronczki M Nature. 2012 Dec 13;492(7428):276-9. doi: 10.1038/nature11773. PMID:23235882[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kawashima T, Hirose K, Satoh T, Kaneko A, Ikeda Y, Kaziro Y, Nosaka T, Kitamura T. MgcRacGAP is involved in the control of growth and differentiation of hematopoietic cells. Blood. 2000 Sep 15;96(6):2116-24. PMID:10979956
- ↑ Toure A, Dorseuil O, Morin L, Timmons P, Jegou B, Reibel L, Gacon G. MgcRacGAP, a new human GTPase-activating protein for Rac and Cdc42 similar to Drosophila rotundRacGAP gene product, is expressed in male germ cells. J Biol Chem. 1998 Mar 13;273(11):6019-23. PMID:9497316
- ↑ Hirose K, Kawashima T, Iwamoto I, Nosaka T, Kitamura T. MgcRacGAP is involved in cytokinesis through associating with mitotic spindle and midbody. J Biol Chem. 2001 Feb 23;276(8):5821-8. Epub 2000 Nov 20. PMID:11085985 doi:http://dx.doi.org/10.1074/jbc.M007252200
- ↑ Toure A, Morin L, Pineau C, Becq F, Dorseuil O, Gacon G. Tat1, a novel sulfate transporter specifically expressed in human male germ cells and potentially linked to rhogtpase signaling. J Biol Chem. 2001 Jun 8;276(23):20309-15. Epub 2001 Mar 5. PMID:11278976 doi:http://dx.doi.org/10.1074/jbc.M011740200
- ↑ Mishima M, Kaitna S, Glotzer M. Central spindle assembly and cytokinesis require a kinesin-like protein/RhoGAP complex with microtubule bundling activity. Dev Cell. 2002 Jan;2(1):41-54. PMID:11782313
- ↑ Lee JS, Kamijo K, Ohara N, Kitamura T, Miki T. MgcRacGAP regulates cortical activity through RhoA during cytokinesis. Exp Cell Res. 2004 Feb 15;293(2):275-82. PMID:14729465
- ↑ Oceguera-Yanez F, Kimura K, Yasuda S, Higashida C, Kitamura T, Hiraoka Y, Haraguchi T, Narumiya S. Ect2 and MgcRacGAP regulate the activation and function of Cdc42 in mitosis. J Cell Biol. 2005 Jan 17;168(2):221-32. Epub 2005 Jan 10. PMID:15642749 doi:10.1083/jcb.200408085
- ↑ Yuce O, Piekny A, Glotzer M. An ECT2-centralspindlin complex regulates the localization and function of RhoA. J Cell Biol. 2005 Aug 15;170(4):571-82. PMID:16103226 doi:10.1083/jcb.200501097
- ↑ Zhao WM, Fang G. MgcRacGAP controls the assembly of the contractile ring and the initiation of cytokinesis. Proc Natl Acad Sci U S A. 2005 Sep 13;102(37):13158-63. Epub 2005 Aug 29. PMID:16129829 doi:http://dx.doi.org/0504145102
- ↑ Kamijo K, Ohara N, Abe M, Uchimura T, Hosoya H, Lee JS, Miki T. Dissecting the role of Rho-mediated signaling in contractile ring formation. Mol Biol Cell. 2006 Jan;17(1):43-55. Epub 2005 Oct 19. PMID:16236794 doi:10.1091/mbc.E05-06-0569
- ↑ Burkard ME, Maciejowski J, Rodriguez-Bravo V, Repka M, Lowery DM, Clauser KR, Zhang C, Shokat KM, Carr SA, Yaffe MB, Jallepalli PV. Plk1 self-organization and priming phosphorylation of HsCYK-4 at the spindle midzone regulate the onset of division in human cells. PLoS Biol. 2009 May 5;7(5):e1000111. doi: 10.1371/journal.pbio.1000111. Epub 2009, May 26. PMID:19468302 doi:10.1371/journal.pbio.1000111
- ↑ Wolfe BA, Takaki T, Petronczki M, Glotzer M. Polo-like kinase 1 directs assembly of the HsCyk-4 RhoGAP/Ect2 RhoGEF complex to initiate cleavage furrow formation. PLoS Biol. 2009 May 5;7(5):e1000110. doi: 10.1371/journal.pbio.1000110. Epub 2009, May 26. PMID:19468300 doi:10.1371/journal.pbio.1000110
- ↑ Lekomtsev S, Su KC, Pye VE, Blight K, Sundaramoorthy S, Takaki T, Collinson LM, Cherepanov P, Divecha N, Petronczki M. Centralspindlin links the mitotic spindle to the plasma membrane during cytokinesis. Nature. 2012 Dec 13;492(7428):276-9. doi: 10.1038/nature11773. PMID:23235882 doi:http://dx.doi.org/10.1038/nature11773
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