KRAS

KRAS (pronounced "k-ras") also known as V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog, is a GTPase that in humans is encoded by the KRAS gene.

The protein product of the normal KRAS gene performs an essential function in normal tissue signaling, and the mutation of a KRAS gene is an essential step in the development of many cancers. Like other members of the ras subfamily, the KRAS protein is a GTPase and is an early player in many signal transduction pathways. KRAS is usually tethered to cell membranes because of the presence of an isoprene group on its C-terminus. There are two protein products of the KRAS gene in mammalian cells that result from the use of alternative exon 4 (exon 4A and 4B respectively): K-Ras4A and K-Ras4B, these proteins have different structure in their C-terminal region and utilise different mechanisms to localize to cellular membranes including plasma membrane.