Ras-like without CAAX protein 1 (RIT1)

Ras-like without CAAX protein 1 (RIT1) is a small GTPase and a member of the Ras family of oncogenes, functioning as a molecular switch that cycles between active (GTP-bound) and inactive (GDP-bound) states to control signal transduction pathways, particularly the RAS/MAPK pathway, which regulates cell proliferation, differentiation, and survival[1][3][7]. Unlike other Ras proteins, RIT1 lacks the CAAX motif for membrane anchoring and instead associates with the plasma membrane via polybasic clusters in its C-terminal region[1]. RIT1 is expressed ubiquitously but is most abundant in tissues such as lung, esophagus, blood, and spleen[1]. Pathogenic mutations in RIT1 are implicated in Noonan syndrome, a congenital disorder characterized by cardiac defects and dysmorphic features, and have also been identified as drivers in certain cancers[3][1]. RIT1 influences not only MAPK/ERK and AKT pathways but also cytoskeletal organization by interacting with small GTPase effectors such as Cdc42 and PAK1[1]. It acts as an oncogene when mutated, promoting uncontrolled signaling that supports tumorigenesis and developmental abnormalities[3][1][7]. Interacting drugs and targeted therapies remain under development or have not yet been specified[1][3].

Other names

GTP-binding protein Rit1RIBBRITROC1MGC125864MGC125865Ras-like protein expressed in many tissuesRas-like without CAAX protein 1Ric-likeGTP-binding protein Roc1NS8