SH domains refer to Src Homology domains, which are protein domains that play a crucial role in protein-protein interactions. These domains were first discovered in the Src tyrosine kinase, hence the name. SH domains are often found in signaling proteins and are involved in several cellular processes, including signal transduction and cytoskeletal rearrangement.
SH domains are characterized by a conserved sequence motif of approximately 100 amino acids. They have the ability to bind to proteins containing phosphorylated tyrosine residues, usually through a specific phosphotyrosine binding pocket. This binding interaction allows SH domains to act as mediators of protein-protein interactions, facilitating the formation of signaling complexes.
One important feature of SH domains is their modular nature. They are often found in combination with other domains, such as SH2 (Src Homology 2) and SH3 (Src Homology 3) domains. These combinations allow for synergistic effects and provide versatility in protein interactome networks.
The function of SH domains can vary depending on the protein context in which they are found. They can serve as adaptor molecules, bringing together multiple signaling proteins into complexes, or act as allosteric regulators, modulating the activity of their binding partners. Additionally, some SH domains have been implicated in protein localization and membrane targeting.
Overall, SH domains play a crucial role in mediating protein-protein interactions in various signaling pathways and are essential for cellular processes such as growth, development, and immunity.
