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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1995-9-5
pubmed:abstractText
Each G protein-coupled receptor can interact only with a limited number of the many structurally similar G proteins expressed within a cell. This study was undertaken to identify single amino acids required for selectively coupling the m3 muscarinic acetylcholine receptor to G proteins of the Gq/11 family. To this goal, distinct intracellular segments/amino acids of the m3 receptor were systematically substituted into the structurally closely related m2 muscarinic receptor, which couples to Gi/o proteins, not Gq/11 proteins. The resultant mutant receptors were expressed in COS-7 cells and studied for their ability to induce agonist-dependent stimulation of phosphatidylinositol hydrolysis, a response known to be mediated by G proteins of the Gq/11 class. Using this approach, we were able to identify four amino acids in the second intracellular loop and four amino acids at the C terminus of the third intracellular loop of the m3 muscarinic receptor that are essential for efficient Gq/11 activation. We could demonstrate that these amino acids, together with a short segment at the N terminus of the third intracellular loop, fully account for the G protein coupling preference of the m3 muscarinic receptor. Taken together, our data strongly suggest that only a limited number of amino acids, located on different intracellular regions, are required to determine the functional profile of a given G protein-coupled receptor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17741-8
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Mapping of single amino acid residues required for selective activation of Gq/11 by the m3 muscarinic acetylcholine receptor.
pubmed:affiliation
Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article