Small GTPase HRas (HRAS)

Small GTPase HRas is a proto-oncogene and a member of the Ras protein family, encoding an enzyme with intrinsic GTPase activity that acts as a molecular switch in signal transduction pathways controlling cell proliferation, differentiation, and survival[2][3][6][7]. It cycles between an active (GTP-bound) and inactive (GDP-bound) state, propagating extracellular signals—especially those from growth factor receptors—to downstream effectors like Raf kinase and PI3-kinase[2][6][7]. HRas activity is regulated by GTPase-activating proteins (GAPs), guanine nucleotide exchange factors (GEFs), and post-translational lipid modifications (farnesylation and palmitoylation) which anchor it to the cell membrane, crucial for its signaling function[3][5]. Oncogenic mutations in HRAS lead to constitutive activation, promoting uncontrolled cell division and cancer (notably bladder, head and neck, and thyroid carcinomas)[2][6][7]. HRas is a validated therapeutic target in oncology, with drugs in development aiming to block its membrane association or downstream signaling.

Other names

H-RasHarvey Rat Sarcoma Viral Oncogene HomologHRAS1c-H-rasHa-RasTransforming protein p21p21ras

Inhibition of farnesylation, preventing HRas membrane localization and activation, leading to suppressed downstream oncogenic signaling[3][5].