SH2 domain-containing protein 2A (SH2D2A)

SH2 domain-containing protein 2A (SH2D2A) is an intracellular adapter protein predominantly expressed in T cells and some endothelial cells, where it acts as a key modulator of early T cell activation and immune homeostasis[1][2][3][5]. It contains an SH2 domain but lacks catalytic activity, functioning by mediating protein-protein interactions among kinases and other signaling molecules. SH2D2A regulates TCR signaling—primarily through interaction with the Src family kinase Lck—and influences downstream events such as cytoskeletal reorganization and cell migration[1][2]. Genetic variants in SH2D2A are associated with increased susceptibility to several autoimmune diseases, presumably because impaired SH2D2A function disrupts the negative regulation of T cell responses[2][3]. The protein is also implicated in vascular biology via VEGF receptor interactions, suggesting roles in angiogenesis[3][5]. No targeted therapeutics exist, but the protein is considered a molecular hub in immune signal transduction and pathogenetic pathways of inflammation and autoimmunity.

Other names

SH2D2ATSAdTSADT cell-specific adapter proteinT cell-specific adaptor proteinT lymphocyte specific adaptor proteinSCAPVRAPVEGF receptor-associated proteinF2771SH22A

Modulation of TCR (T-cell receptor) downstream kinases such as Lck by site-specific tyrosine phosphorylation Scaffolding/adapter function facilitating or inhibiting signaling protein complexes