The Grb2 adaptor.
Grb2 is an 'adaptor' protein made of one SH2 and two SH3 domains. The SH3 domains bind to prolinerich motifs in the C-terminal part of the ras exchange factor Sos. Binding of the Grb2 SH2 domain to phosphotyrosine motifs on receptors, or other adaptor proteins such as Shc, recruits this Grb2/Sos complex at the plasma membrane where Sos stimulates nucleotide exchange on ras, then ras activates raf and leads to MAP kinase activation. The structure of Grb2, the precise motifs recognised by its SH2 and SH3 domains, the way Grb2 performs its function, a possible regulation of its association with Sos, and its ability to complex with other proteins in vivo, are discussed.
Chardin
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P
Institut de Pharmacologie Moléculaire et Cellulaire du CNRS 660, Valbonne, France.
Cussac
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D
Maignan
S
S
Ducruix
A
A
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D051380:GRB2 Adaptor Protein; D008565:Membrane Proteins / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D020664:Son of Sevenless Proteins
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; D008565:Membrane Proteins; D011506:Proteins; D020664:Son of Sevenless Proteins; D011505:Protein-Tyrosine Kinases