RACGAP1

This gene encodes a GTPase-activating protein (GAP) that is a compoment of the centralspindlin complex. This protein binds activated forms of Rho GTPases and stimulates GTP hydrolysis, which results in negative regulation of Rho-mediated signals. This protein plays a regulatory role in cytokinesis, cell growth, and differentiation. Alternatively spliced transcript variants have been found for this gene. There is a pseudogene for this gene on chromosome 12. [provided by RefSeq, Feb 2016]

Rac GTPase Activating Protein 1

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. Required for proper attachment of the midbody to the cell membrane during 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.

Biological Process actomyosin contractile ring assemblyManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process mitotic cytokinesisManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process mitotic spindle midzone assemblyManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process neuroblast proliferationISS:UniProtKB
Biological Process positive regulation of cytokinesisManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process regulation of attachment of spindle microtubules to kinetochoreManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process regulation of embryonic developmentISS:UniProtKB
Biological Process regulation of small GTPase mediated signal transductionTAS:Reactome
Biological Process Rho protein signal transductionManual Assertion Based On ExperimentIBA:GO_Central
Biological Process spermatogenesisManual Assertion Based On ExperimentIEP:UniProtKB
Biological Process sulfate transportManual Assertion Based On ExperimentIDA:UniProtKB

Nucleus
Cytoplasm
Cytoplasm, cytoskeleton, spindle
Cytoplasmic vesicle, secretory vesicle, acrosome
Cleavage furrow
Midbody, Midbody ring
Cell membrane
Colocalizes with RND2 in Golgi-derived proacrosomal vesicles and the acrosome (By similarity).
During interphase, localized to the nucleus and cytoplasm along with microtubules, in anaphase, is redistributed to the central spindle and, in telophase and cytokinesis, to the midbody ring, also called Flemming body. Colocalizes with RHOA at the myosin contractile ring during cytokinesis. Colocalizes with ECT2 to the mitotic spindles during anaphase/metaphase, the cleavage furrow during telophase and at the midbody at the end of cytokinesis. Colocalizes with Cdc42 to spindle microtubules from prometaphase to telophase.

Phosphorylated at multiple sites in the midbody during cytokinesis (PubMed:12689593).
Phosphorylation by AURKB on Ser-387 at the midbody is, at least in part, responsible for exerting its latent GAP activity towards RhoA (PubMed:12689593).
Phosphorylation on multiple serine residues by PLK1 enhances its association with ECT2 and is critical for cleavage furrow formation (PubMed:19468302, PubMed:19468300).
Phosphorylation on Ser-164 plays a major role in mediating interaction with ECT2 (PubMed:25068414).
Phosphorylation on Ser-157 does not appear to contribute to binding to ECT2 (PubMed:25068414).