Submit Data |  Help |  Video Tutorials |  News |  Publications |  FTP Download |  REST API |  Citing RGD |  Contact   

Novel small GTPase M-Ras participates in reorganization of actin cytoskeleton.

Authors: Matsumoto, K  Asano, T  Endo, T 
Citation: Matsumoto K, etal., Oncogene 1997 Nov 13;15(20):2409-17.
Pubmed: (View Article at PubMed) PMID:9395237
DOI: Full-text: DOI:10.1038/sj.onc.1201416

During an attempt to elucidate regulatory mechanisms of skeletal muscle cell differentiation, we cloned cDNAs encoding a novel small GTPase from cDNA libraries of the mouse skeletal muscle cell line C2 and rat brain. It was designated as M-Ras due to the structural similarity to Ras family proteins. M-Ras contained conserved motifs for GDP/GTP-binding and GTPase activities, whereas it varied from the other Ras family proteins at several amino acids within the extended effector domain. From the C-terminal sequence, M-Ras is presumed to be anchored to the cell membrane with a geranylgeranyl group in combination with a polybasic region. Bacterially expressed recombinant M-Ras exerted the GTP-binding and GTPase activities. A mutant M-RasG22V was unable to hydrolyze bound GTP, indicating that it serves as a constitutively active form. Epitope-tagging experiments showed that M-Ras was concentrated on certain plasma membrane-associated structures. Transfection of M-Ras cDNA and microinjection of the M-RasG22V protein into fibroblasts induced formation of the peripheral microspikes. In addition, the actin stress fibers disappeared and instead numerous actin foci were formed in the injected cells. The transfected cells eventually exhibited dendritic appearances with microspikes. Consequently, M-Ras is likely to participate in reorganization of the actin cytoskeleton.


Objects referenced in this article

Additional Information

RGD Object Information
RGD ID: 729080
Created: 2003-11-25
Species: All species
Last Modified: 2003-11-25
Status: ACTIVE


RGD is funded by grant HL64541 from the National Heart, Lung, and Blood Institute on behalf of the NIH.