SH2 Domain Containing Protein 3A (SH2D3A)

Adaptor proteins mediate interactions between membrane receptors and transcription factors through 1 or more domains in the adaptor protein. By searching an EST database for sequences with signal transduction motifs, Lu et al. (1999) identified a cDNA encoding a deduced 576-amino acid protein, which they named NSP1.

NSP1 also contains a potential SH3 interaction domain. Northern blot analysis detected significant levels of a 2.7-kb NSP1 transcript only in placenta, pancreas, kidney, lung, fetal kidney, and fetal lung.In contrast, contact with fibronectin resulted in little phosphorylation of NSP1 but increased phosphorylation of the p130-Cas associated with NSP1. Expression of NSP1 led to activation of the stress-activated protein kinase JNK1 (MAPK8), but not ERK2 (MAPK1).