Reference - Detail
|Author||Nishimura K, Oki T, Kitaura J, Kuninaka S, Saya H, Sakaue-Sawano A, Miyawaki A, Kitamura T.|
|Title||APC(CDH1) targets MgcRacGAP for destruction in the late M phase.|
BACKGROUND:Male germ cell RacGTPase activating protein (MgcRacGAP) is an important regulator of the Rho family GTPases--RhoA, Rac1, and Cdc42--and is indispensable in cytokinesis and cell cycle progression. Inactivation of RhoA by phosphorylated MgcRacGAP is an essential step in cytokinesis. MgcRacGAP is also involved in G1-S transition and nuclear transport of signal transducer and activator of transcription 3/5 (STAT3/5). Expression of MgcRacGAP is strictly controlled in a cell cycle-dependent manner. However, the underlying mechanisms have not been elucidated.
METHODOLOGY/PRINCIPAL FINDINGS:Using MgcRacGAP deletion mutants and the fusion proteins of full-length or partial fragments of MgcRacGAP to mVenus fluorescent protein, we demonstrated that MgcRacGAP is degraded by the ubiquitin-proteasome pathway in the late M to G1 phase via APC(CDH1). We also identified the critical region for destruction located in the C-terminus of MgcRacGAP, AA537-570, which is necessary and sufficient for CDH1-mediated MgcRacGAP destruction. In addition, we identified a PEST domain-like structure with charged residues in MgcRacGAP and implicate it in effective ubiquitination of MgcRacGAP.
CONCLUSIONS/SIGNIFICANCE:Our findings not only reveal a novel mechanism for controlling the expression level of MgcRacGAP but also identify a new target of APC(CDH1). Moreover our results identify a C-terminal region AA537-570 of MgcRacGAP as its degron.
|MeSH||Animals Antigens, CD Blotting, Western Cadherins / genetics Cadherins / metabolism* Cdh1 Proteins / genetics Cdh1 Proteins / metabolism* Cell Cycle Cell Line Flow Cytometry G1 Phase / genetics G1 Phase / physiology GTPase-Activating Proteins / genetics GTPase-Activating Proteins / metabolism* Humans Immunohistochemistry Immunoprecipitation Mice NIH 3T3 Cells Protein Binding Resting Phase, Cell Cycle / genetics Resting Phase, Cell Cycle / physiology|
|DNA material||mCherry-hCdt1(30/120)/ pCSII-EF (RDB15273) AmCyan-hGem(1/110)/pCSII-EF (RDB15274)|