Src kinase-associated phosphoprotein 1 is an adapter protein that in humans is encoded by the SKAP1 gene.

This gene encodes a T cell adaptor protein, a class of intracellular molecules with modular domains capable of recruiting additional proteins but that exhibit no intrinsic enzymatic activity. The encoded protein contains a unique N-terminal region followed by a PH domain and C-terminal SH3 domain. Along with the adhesion and degranulation-promoting adaptor protein, the encoded protein plays a critical role in inside-out signaling by coupling T-cell antigen receptor stimulation to the activation of integrins. [provided by RefSeq, Jul 2008].
Function: Positively regulates T-cell receptor signaling by enhancing the MAP kinase pathway. Required for optimal conjugation between T-cells and antigen-presenting cells by promoting the clustering of integrin ITGAL on the surface of T-cells. May be involved in high affinity immunoglobulin epsilon receptor signaling in mast cells.