Grb2 is an adaptor protein that plays a key role in cell signaling. It contains one SH2 domain flanked by two SH3 domains, which allow it to bind to tyrosine phosphorylated proteins and form complexes with other proline-rich proteins. This enables Grb2 to transmit signals from growth factor receptors to downstream proteins like Ras and the ERK kinases. The SH2 domain specifically recognizes phosphotyrosine motifs to determine what other molecules Grb2 interacts with.

1. 1. Growth factor receptor-bound protein 2 (Grb2) is an adaptor protein widely expressed and
involved in signal transduction/cell communication. Grb2 major function is on the epidermal
growth factor receptor tyrosine kinase to acivate Ras and its downstream kinases, ERK1, 2.
2. Grb2 has one SH2 domain and two SH3 domains, SH2 domain is the central domain and SH3
domain present in each sides. SH3 domains direct complex formation with proline-rich regions
of other proteins, and SH2 domain binds tyrosine phosphorylated sequences rendering signal
transduction.
3. The specificity of SH2 interactions with other molecules is determined by its ability to
specifically recognize phosphotyrosine (pY)-containing motifs within their target proteins.
Solution
1. Growth factor receptor-bound protein 2 (Grb2) is an adaptor protein widely expressed and
involved in signal transduction/cell communication. Grb2 major function is on the epidermal
growth factor receptor tyrosine kinase to acivate Ras and its downstream kinases, ERK1, 2.
2. Grb2 has one SH2 domain and two SH3 domains, SH2 domain is the central domain and SH3
domain present in each sides. SH3 domains direct complex formation with proline-rich regions
of other proteins, and SH2 domain binds tyrosine phosphorylated sequences rendering signal
transduction.
3. The specificity of SH2 interactions with other molecules is determined by its ability to
specifically recognize phosphotyrosine (pY)-containing motifs within their target proteins.