Document Detail


Transforming activity of the Rho family GTPase, Wrch-1, a Wnt-regulated Cdc42 homolog, is dependent on a novel carboxyl-terminal palmitoylation motif.
MedLine Citation:
PMID:  16046391     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Wrch-1 is a Rho family GTPase that shares strong sequence and functional similarity with Cdc42. Like Cdc42, Wrch-1 can promote anchorage-independent growth transformation. We determined that activated Wrch-1 also promoted anchorage-dependent growth transformation of NIH 3T3 fibroblasts. Wrch-1 contains a distinct carboxyl-terminal extension not found in Cdc42, suggesting potential differences in subcellular location and function. Consistent with this, we found that Wrch-1 associated extensively with plasma membrane and endosomes, rather than with cytosol and perinuclear membranes like Cdc42. Like Cdc42, Wrch-1 terminates in a CAAX tetrapeptide (where C is cysteine, A is aliphatic amino acid, and X is any amino acid) motif (CCFV), suggesting that Wrch-1 may be prenylated similarly to Cdc42. Most surprisingly, unlike Cdc42, Wrch-1 did not incorporate isoprenoid moieties, and Wrch-1 membrane localization was not altered by inhibitors of protein prenylation. Instead, we showed that Wrch-1 is modified by the fatty acid palmitate, and pharmacologic inhibition of protein palmitoylation caused mislocalization of Wrch-1. Most interestingly, mutation of the second cysteine of the CCFV motif (CCFV > CSFV), but not the first, abrogated both Wrch-1 membrane localization and transformation. These results suggest that Wrch-1 membrane association, subcellular localization, and biological activity are mediated by a novel membrane-targeting mechanism distinct from that of Cdc42 and other isoprenylated Rho family GTPases.
Authors:
Anastacia C Berzat; Janice E Buss; Emily J Chenette; Carolyn A Weinbaum; Adam Shutes; Channing J Der; Audrey Minden; Adrienne D Cox
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2005-07-26
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  280     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  2005 Sep 
Date Detail:
Created Date:  2005-09-19     Completed Date:  2005-11-28     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  33055-65     Citation Subset:  IM    
Affiliation:
Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, 27599-7512, USA.
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MeSH Terms
Descriptor/Qualifier:
Amino Acid Motifs
Amino Acid Sequence
Animals
Biotin / chemistry
Blotting, Western
Cell Adhesion
Cell Membrane / metabolism
Cell Proliferation
Cysteine / chemistry
Cytosol / metabolism
Endosomes / metabolism
Esters / chemistry
Green Fluorescent Proteins / metabolism
Mice
Microscopy, Fluorescence
Molecular Sequence Data
Mutagenesis, Site-Directed
Mutation
NIH 3T3 Cells
Palmitic Acid / chemistry
Protein Binding
Protein Structure, Tertiary
Recombinant Proteins / chemistry
Sequence Homology, Amino Acid
Signal Transduction
Transfection
cdc42 GTP-Binding Protein / metabolism*
rho GTP-Binding Proteins / metabolism*
Grant Support
ID/Acronym/Agency:
CA103143/CA/NCI NIH HHS; CA109550/CA/NCI NIH HHS; CA51890/CA/NCI NIH HHS; CA63071/CA/NCI NIH HHS; CA67771/CA/NCI NIH HHS; GM46372/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Esters; 0/Recombinant Proteins; 147336-22-9/Green Fluorescent Proteins; 52-90-4/Cysteine; 57-10-3/Palmitic Acid; 58-85-5/Biotin; EC 3.6.1.-/RHOU protein, human; EC 3.6.5.2/cdc42 GTP-Binding Protein; EC 3.6.5.2/rho GTP-Binding Proteins

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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