Src-associated adaptor protein Skap2 with 1u5e code
Signal transducing adaptor proteins (STAPs) are proteins that are accessory to main proteins in a signal transduction pathway.[1] Adaptor proteins contain a variety of protein-binding modules that link protein-binding partners together and facilitate the creation of larger signaling complexes. These proteins tend to lack any intrinsic enzymatic activity themselves,[2] instead mediating specific protein–protein interactions that drive the formation of protein complexes. Examples of adaptor proteins include MYD88,[3][4]Grb2 and SHC1.
Signaling components
Much of the specificity of signal transduction depends on the recruitment of several signalling components such as protein kinases and G-protein GTPases into short-lived active complexes in response to an activating signal such as a growth factor binding to its receptor.
Domains
Adaptor proteins usually contain several domains within their structure (e.g., Src homology 2 (SH2) and SH3 domains) that allow specific interactions with several other specific proteins. SH2 domains recognise specific amino acid sequences within proteins containing phosphotyrosine residues and SH3 domains recognise proline-rich sequences within specific peptide sequence contexts of proteins.
There are many other types of interaction domains found within adaptor and other signalling proteins that allow a rich diversity of specific and coordinated protein–protein interactions to occur within the cell during signal transduction.
Examples of adaptor proteins
Adaptor proteins include:
BCAR3 – Breast cancer anti-estrogen resistance protein 3
