p190

P190 is a designation most often used for a family of Rho GTPase activating proteins (RhoGAPs) with an approximate molecular weight of 190 kDa. In humans, the two best characterized members are ARHGAP5, known as p190-B, and ARHGAP35, known as p190-A. These proteins regulate Rho family GTPases, including RhoA, Rac1, and Cdc42, by accelerating the hydrolysis of GTP to GDP, thereby inactivating the GTPases and influencing actin cytoskeleton dynamics, cell adhesion, migration, and cell shape.

Structurally, p190 proteins possess a RhoGAP catalytic domain near the C-terminus and carry various regulatory and interaction motifs that differ between the p190-A and p190-B paralogs. They function within signaling networks downstream of tyrosine kinases and receptor pathways, and can form complexes with other signaling proteins such as p120RasGAP and additional adapters. Phosphorylation and proteolytic processing can modulate their activity and interactions, integrating signals that control cytoskeletal remodeling.

In development and disease, p190 proteins contribute to neural development, neuronal migration, vascular biology, and hematopoiesis. Dysregulation of p190 function or expression can perturb cell motility and morphology, and has been associated with cancer progression and other pathologies in certain cellular contexts. As regulators of Rho GTPase signaling, p190 proteins are used as models to study cytoskeletal control and have been explored for potential therapeutic targeting in diseases where Rho pathway signaling is disrupted.

The term p190 can also refer to other unrelated uses that share the same name, so disambiguation may be required in specific contexts.