Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-2-29
pubmed:abstractText
Signal transfer between the protease-activated PAR1 thrombin receptor and membrane-associated heterotrimeric G proteins is mediated by protein-protein interactions. We constructed a yeast signaling system that resolves domain-specific functions of binding from coupling in the Galpha subunit. The endogenous yeast Galpha subunit, Gpa1, does not bind to PAR1 and served as a null structural template. N- and C-terminal portions of mammalian G(i2) and G(16) were substituted back into the Gpa1 template and gain-of-function assessed. The C-terminal third of G(16), but not of G(i2), provides sufficient interactions for coupling to occur with PAR1. The N-terminal two-thirds of G(i2) also contains sufficient determinants to bind and couple to PAR1 and overcome the otherwise negative or missing interactions supplied by the C-terminal third of Gpa1. Replacement of the N-terminal alpha-helix of G(i2), residues 1-34, with those of Gpa1 abolishes coupling but not binding to PAR1 or to betagamma subunits. These data support a model that the N-terminal alphaN helix of the Galpha subunit is physically interposed between PAR1 and the Gbeta subunit and directly assists in transferring the signal between agonist-activated receptor and G protein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2627-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
PAR1 thrombin receptor-G protein interactions. Separation of binding and coupling determinants in the galpha subunit.
pubmed:affiliation
Molecular Cardiology Research Institute, Division of Hematology, New England Medical Center, Boston, Massachusetts 02111, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't