Adapter molecule crk
Adapter molecule crk also known as proto-oncogene c-Crk is a protein that in humans is encoded by the "CRK" gene. The CRK protein participates in the Reelin signaling cascade downstream of DAB1. Function. Adapter molecule crk is a member of an adapter protein family that binds to several tyrosine-phosphorylated proteins. This protein has several SH2 and SH3 domains (src-homology domains) and is involved in several signaling pathways, recruiting cytoplasmic proteins in the vicinity of tyrosine kinase through SH2-phosphotyrosine interaction. The N-terminal SH2 domain of this protein functions as a positive regulator  of transformation whereas the C-terminal SH3 domain functions as a negative regulator of transformation. Two alternative transcripts encoding different isoforms with distinct biological activity have been described. Crk together with CrkL participates in the Reelin signaling cascade downstream of DAB1. v-Crk, a transforming oncoprotein from avian sarcoma viruses, is a fusion of viral "gag" protein with the SH2 and SH3 domains of cellular Crk. The name Crk is from "CT10 Regulator of Kinase" where CT10 is the avian virus from which was isolated a protein, lacking kinase domains, but capable of stimulating phosphorylation of tyrosines in cells. Crk  should not be confused with Src, which also has cellular (c-Src) and viral (v-Src) forms and is involved in some of the same signaling pathways but is a protein tyrosine-kinase. Interactions. CRK (gene) has been shown to interact with: