ROS [MD256]

ROS or ROS1, a 263914 Da cell membrane tyrosine kinase expressed in brain, and an orphan receptor tyrosine kinase of the insulin receptor family, was initially identified as a homolog of v-ros from the UR2 sarcoma virus. ROS consists of a large extracellular domain that is composed of six fibronectin repeats, a transmembrane domain, and an intracellular kinase domain. While the function of ROS is undefined, it has been shown to play an important role in differentiation of epididymal epithet. The first oncogenic fusion of ROS, FIG-ROS1, was initially identified by research studies in glioblast, and subsequent studies have found this fusion in cholangiocarcinoa, ovarian can and non-small cell lung cancer (NSCLC). Investigators have found additional oncogenic ROS fusion proteins in NSCLC (at a frequency of ~1.6%), where the ROS1 kinase domain is fused to the amino-terminal region of a number of different proteins, including CD74 and SLC34A. ROS fusion proteins activate the SHP-2 phosphatase, PI3K/Akt/mTOR, Erk, and Stat3 pathway.