Src-associated adaptor protein Skap2 with 1u5e code
Signal transducing adaptor proteins are proteins which are accessory to main proteins in a signal transduction pathway. 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 but instead mediate specific protein–protein interactions that drive the formation of protein complexes. Examples of adaptor proteins include MyD88, Grb2 and SHC1.
Adaptor proteins usually contain several domains within their structure (e.g., Src homology 2 (SH2) and SH3 domains) which 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 which allow a rich diversity of specific and coordinated protein–protein interactions to occur within the cell during signal transduction.
TAB2 is an adaptor protein involved in the IL-1 signal transduction pathway: Takaesu, Giichi; Kishida, Satoshi; Hiyama, Atsushi; Yamaguchi, Kyoko; Shibuya, Hiroshi; Irie, Kenji; Ninomiya-Tsuji, Jun; Matsumoto, Kunihiro (2000). "TAB2, a Novel Adaptor Protein, Mediates Activation of TAK1 MAPKKK by Linking TAK1 to TRAF6 in the IL-1 Signal Transduction Pathway". Molecular Cell5 (4): 649–658. doi:10.1016/S1097-2765(00)80244-0. ISSN1097-2765. PMID10882101.
A good article regarding the role of adaptor proteins involved with the T-cell antigen receptor: Samelson, Lawrence E. (2002). "SIGNALTRANSDUCTIONMEDIATED BY THET CELLANTIGENRECEPTOR: The Role of Adapter Proteins*". Annual Review of Immunology20 (1): 371–394. doi:10.1146/annurev.immunol.20.092601.111357. ISSN0732-0582.