These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: A small region in phosducin inhibits G-protein betagamma-subunit function.
    Author: Blüml K, Schnepp W, Schröder S, Beyermann M, Macias M, Oschkinat H, Lohse MJ.
    Journal: EMBO J; 1997 Aug 15; 16(16):4908-15. PubMed ID: 9305633.
    Abstract:
    G-protein betagamma-subunits (G(betagamma)) are active transmembrane signalling components. Their function recently has been observed to be regulated by the cytosolic protein phosducin. We show here that a small fragment (amino acids 215-232) contained in the C-terminus of phosducin is sufficient for high-affinity interactions with G(betagamma). Corresponding peptides not only disrupt G(betagamma)-G(alpha) interactions, as defined by G(betagamma)-stimulated GTPase activity of alpha(o), but also other G(betagamma)-mediated functions. The NMR structure of a peptide encompassing this region shows a loop exposing the side chains of Glu223 and Tyr224, and peptides with a substitution of either of these amino acids show a complete loss of activity towards G(o). Mutation of this Tyr224 to Ala in full-length phosducin reduced the functional activity of phosducin to that of phosducin's isolated N-terminus, indicating the importance of this residue within the short, structurally defined C-terminal segment. This small peptide derived from phosducin, may represent a model of a G(betagamma) inhibitor, and illustrates the potential of small compounds to affect G(betagamma) functions.
    [Abstract] [Full Text] [Related] [New Search]