Ly-GDI, a GDP-dissociation inhibitor of the RhoA GTP-binding protein, is expressed preferentially in lymphocytes.
AUTOR(ES)
Scherle, P
RESUMO
The Ras-related small GTP-binding proteins are involved in diverse cellular events, including cell signaling, proliferation, cytoskeletal organization, and secretion. The interconversion of the active, GTP-bound form of the protein to the inactive, GDP-bound form is influenced by two types of regulatory proteins, those that alter the intrinsic GTPase activity of the GTP-binding protein and those that affect the rate of GDP/GTP exchange. By utilizing a subtractive hybridization approach, we have isolated a human gene encoding Ly-GDI, a protein that has striking homology to the product of a previously cloned gene, Rho-GDI, which inhibits GDP/GTP exchange on the Rho family of GTPases. In contrast to Rho-GDI, which is ubiquitously expressed, Ly-GDI is expressed only in hematopoietic tissues and predominantly in B- and T-lymphocyte cell lines. The full-length Ly-GDI cDNA encodes a 27-kDa protein which binds to RhoA and inhibits GDP dissociation from RhoA. Stimulation of T lymphocytes with phorbol ester leads to phosphorylation of Ly-GDI, suggesting an involvement of Ly-GDI in lymphocyte activation pathways. Cell type-specific regulators of the Ras-like GTP-binding proteins may provide one mechanism by which different cell types respond uniquely to signals transduced through the same cell surface receptor or may provide a way by which the GTP-binding proteins can be uniquely engaged by tissue-restricted receptors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=47183Documentos Relacionados
- cDNA cloning of a human mRNA preferentially expressed in hematopoietic cells and with homology to a GDP-dissociation inhibitor for the rho GTP-binding proteins.
- RhoGDIγ: A GDP-dissociation inhibitor for Rho proteins with preferential expression in brain and pancreas
- The GTP-binding Protein RhoA Mediates Na,K-ATPase Exocytosis in Alveolar Epithelial Cells
- Involvement of a Small GTP-binding Protein (G Protein) Regulator, Small G Protein GDP Dissociation Stimulator, in Antiapoptotic Cell Survival Signaling
- The low molecular mass GTP-binding protein Rho is affected by toxin A from Clostridium difficile.