CYK-4: A Rho family gtpase activating protein (GAP) required for central spindle formation and cytokinesis
| Autor: | Jantsch-Plunger, V., Gönczy, P., Romano, A., Schnabel, H., Hamill, D., Schnabel, R., Hyman, A. A., Glotzer, M. |
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| Rok vydání: | 2000 |
| Předmět: |
Male
rho GTP-Binding Proteins cell division GTPase-Activating Proteins/genetics/*metabolism Protein Structure Embryo Nonmammalian spindle midzone rho GTP-Binding Proteins/genetics/*metabolism Kinesins Spindle Apparatus Tertiary/genetics Models Biological kinesin Models Subcellular Fractions/metabolism Animals Humans Caenorhabditis elegans Proteins Cloning Molecular Caenorhabditis elegans Child Caenorhabditis elegans/cytology/*genetics/*metabolism Mutation/physiology Nonmammalian Caenorhabditis elegans/cytology Caenorhabditis elegans/genetics Cell Division/physiology Female GTPase-Activating Proteins/genetics GTPase-Activating Proteins/metabolism Gene Expression Regulation Developmental/physiology Helminth Proteins/genetics Helminth Proteins/metabolism Kinesin/genetics Kinesin/metabolism Mitotic Spindle Apparatus/physiology Protein Structure Tertiary/genetics rho GTP-Binding Proteins/genetics rho GTP-Binding Proteins/metabolism GTPase-Activating Proteins Rho GTPase Molecular Gene Expression Regulation Developmental Developmental/physiology Mitotic Spindle Apparatus/*physiology Helminth Proteins Kinesin/genetics/metabolism Biological Cell Division/*physiology Protein Structure Tertiary Helminth Proteins/genetics/*metabolism Gene Expression Regulation Embryo Mutation Original Article Cloning Subcellular Fractions |
| Zdroj: | The Journal of Cell Biology Journal of Cell Biology, vol. 149, no. 7, pp. 1391-1404 |
| ISSN: | 0021-9525 |
| Popis: | During cytokinesis of animal cells, the mitotic spindle plays at least two roles. Initially, the spindle positions the contractile ring. Subsequently, the central spindle, which is composed of microtubule bundles that form during anaphase, promotes a late step in cytokinesis. How the central spindle assembles and functions in cytokinesis is poorly understood. The cyk-4 gene has been identified by genetic analysis in Caenorhabditis elegans. Embryos from cyk-4(t1689ts) mutant hermaphrodites initiate, but fail to complete, cytokinesis. These embryos also fail to assemble the central spindle. We show that the cyk-4 gene encodes a GTPase activating protein (GAP) for Rho family GTPases. CYK-4 activates GTP hydrolysis by RhoA, Rac1, and Cdc42 in vitro. RNA-mediated interference of RhoA, Rac1, and Cdc42 indicates that only RhoA is essential for cytokinesis and, thus, RhoA is the likely target of CYK-4 GAP activity for cytokinesis. CYK-4 and a CYK-4:GFP fusion protein localize to the central spindle and persist at cell division remnants. CYK-4 localization is dependent on the kinesin-like protein ZEN-4/CeMKLP1 and vice versa. These data suggest that CYK-4 and ZEN-4/CeMKLP1 cooperate in central spindle assembly. Central spindle localization of CYK-4 could accelerate GTP hydrolysis by RhoA, thereby allowing contractile ring disassembly and completion of cytokinesis. |
| Databáze: | OpenAIRE |
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