Signal transducing adaptor proteins are proteins which are accessory to main proteins in a signal transduction pathway. These proteins tend to lack any intrinsic enzymatic activity themselves[1] but instead mediate specific protein–protein interactions that drive the formation of protein complexes. Examples of adaptor proteins include MyD88, Grb2 and SHC1.
Contents |
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.
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.
Genes encoding adaptor proteins include:
|
||||||||||||||||||||||||||||
|
||||||||||||||||||||
|
||||||||||||||