The Regulatory And Mechanism Of Rap2 On Microfilament Cytoskeleton Structure

Rap2 belongs to Ras family of Rap subtribe,Rap include Rap1 and Rap2,a large number of literature shows that the Ras and Rap1 regulate the cytoskeleton,cell adhesion,and other functions,Rap2 60% homology in amino acid sequence with Rap1, 46% homology with the Ras,and Rap2 specific effectors MAP4K4 、MINK、 TINK、 PARG indicate Rap2 may contact with microfilament cytoskeleton,this article mainly explore the relationship between Rap2 and microfilament cytoskeleton and its regulatory mechanism,for further research on Rap2 signaling.This paper first compare the morphological change when stability and transient expressed Rap2 by cell staining method,We find when NC65, CRL1932,CCF-RC-2 cells expressed Rap2,there are more than 60% cells became round,stress fiber disorder,cells lose the original state of spreading, actin and Rap2 has a tendency to colocation,secondly by the method of using living cells work station dynamic observe Rap2 on microfilament cytoskeleton,We found in Rap2 expressed cells, cell polarity disappears, microfilament skeleton disorder,Rap2 RNAi, cell movement ability slow down, stress fiber disorder,and advance into apoptosis, For its regulatory mechanism,using GST-Pull Down method found in the Rap2 stable expressed cell Rap2 significantly reduce Rho A protein activity,enhance Rac1 activity,reduce Cdc42 activity;Immunofluorescence method after transient expression Rap2 in the CRL1932, CRL1933 FAKY397、Paxillin and Vinculin dying, found in transfection Rap2, about 60% cell polarity loss or polarity homogenization,And Rap2 inhibit FAKY397 phosphorylation level.To sum up, Rap2 significantly make microfilament cytoskeleton disorder, by reducing Rho A protein activity,enhancing Rac1 activity,reducing Cdc42 activ ityb,Altering the cellfocal adhersion protein polarity.