KH Domain Containing, RNA Binding, Signal Transduction Associated Protein 1 (KHDRBS1)

SAM68 is a tyrosine-phosphorylated, SRC-associated protein in mitotic cells.SAM68 protein contains 3 N-terminal proline-rich sequences, followed by a KH domain embedded within a STAR domain, 3 more proline-rich sequences, a C-terminal tyrosine-rich region, which contains a domain similar to the SRGY domain of RNA-binding proteins, and a putative nuclear localization signal. SAM68 has a calculated molecular mass of 48.2 kD, but it migrated as a 68-kD protein on SDS-PAGE gels. Northern blot analysis detected a 3.1-kb SAM68 transcript expressed at moderate levels in heart, brain, placenta, skeletal muscle, kidney, and pancreas, and at lower levels in lung and liver.The p62/SAM68 gene was phosphorylated when expressed in the presence of v-src, and only the phosphorylated form bound to GAP.