Ras-related protein Rap-1A (RAP1A) (RAP1A)

Ras-related protein Rap-1A (RAP1A) is a small GTPase of the Ras superfamily that functions as a molecular switch, transitioning between an active GTP-bound state and an inactive GDP-bound state (UniProt). It is a critical regulator of cellular adhesion, integrin activation, and the formation of cell-cell junctions, particularly in endothelial and epithelial tissues (GeneCards). RAP1A is also involved in various signaling pathways, such as the MAPK/ERK cascade, and has been implicated in the progression of several cancers, including ovarian, prostate, and esophageal squamous cell carcinoma, where it promotes metastasis and proliferation (PubMed). Recent studies have highlighted its role in metabolic regulation, demonstrating that metformin exerts its glucose-lowering effects by inhibiting RAP1A activity in specific hypothalamic neurons (Science Advances, 2025). While there are currently no approved drugs that specifically target RAP1A, it is an active area of research for small molecule inhibitors, prenylation blockers like geranylgeranyltransferase inhibitors (GGTIs), and RNA-based therapies such as siRNAs and miRNAs (Open Targets). Therapeutic modulation of RAP1A must be carefully managed due to its essential roles in maintaining vascular integrity and normal cell adhesion (NIH).

Other names

KREV1RAP1SMGP21C21KGG-22KGTP-binding protein smg p21ARas-related protein Krev-1

RAP1A activity is modulated through several mechanisms: small molecules like metformin inhibit its activation in the brain to regulate glucose levels; geranylgeranyltransferase inhibitors (GGTIs) prevent its essential post-translational prenylation and membrane localization; and experimental RNA interference (siRNA/shRNA) or microRNAs (e.g., miR-203) target RAP1A mRNA to reduce protein expression (Science Advances, 2025; Cancer Research, 1997).