Phospho-GRF-1 (Tyr1105) Antibody - #AF3484

Rho GTPase-activating protein (GAP). Binds several acidic phospholipids which inhibits the Rho GAP activity to promote the Rac GAP activity. This binding is inhibited by phosphorylation by PRKCA. Involved in cell differentiation as well as cell adhesion and migration, plays an important role in retinal tissue morphogenesis, neural tube fusion, midline fusion of the cerebral hemispheres and mammary gland branching morphogenesis (By similarity). Transduces signals from p21-ras to the nucleus, acting via the ras GTPase-activating protein (GAP) (By similarity). Transduces SRC-dependent signals from cell-surface adhesion molecules, such as laminin, to promote neurite outgrowth. Regulates axon outgrowth, guidance and fasciculation (By similarity). Modulates Rho GTPase-dependent F-actin polymerization, organization and assembly, is involved in polarized cell migration and in the positive regulation of ciliogenesis and cilia elongation (By similarity). During mammary gland development, is required in both the epithelial and stromal compartments for ductal outgrowth (By similarity). Represses transcription of the glucocorticoid receptor by binding to the cis-acting regulatory sequence 5'-GAGAAAAGAAACTGGAGAAACTC-3'; this function is however unclear and would need additional experimental evidences.

Phosphorylation of Tyr-1105 by PTK6 promotes the association with RASA1, inactivating RHOA while activating RAS. Phosphorylation at Tyr-308 by PDGFRA inhibits binding to GTF2I. Phosphorylated by PRKCA at Ser-1221 and Thr-1226, induces relocalization from the cytoplasm to regions of plasma membrane ruffling and prevents the binding and substrate specificity regulation by phospholipids. In brain, phosphorylated by FYN and SRC (By similarity). During focal adhesion formation, phosphorylated by MAPK1 and MAPK3 at the C-terminal region, probably at Ser-1451, Ser-1476, Thr-1480 and Ser-1483. Phosphorylation by MAPK1 and MAPK3 inhibits GAP function and localizes ARGHAP35 away from newly forming focal adhesions and stress fibers in cells spreading on fibronectin (By similarity). Phosphorylation at Ser-1476 and Thr-1480 by GSK3B requires priming by MAPK and inhibits RhoGAP activity and modulates polarized cell migration (By similarity).

Cytoplasm>Cytoskeleton>Cilium basal body. Cytoplasm. Nucleus. Cell membrane.
Note: In response to integrins and SDC4 and upon phosphorylation by PKC, relocalizes from the cytoplasm to regions of plasma membrane ruffling where it colocalizes with polymerized actin.

Detected in neutrophils (at protein level).

Interacts with RASA1 (By similarity). Interacts with the general transcription factor GTF2I, the interaction sequesters GTF2I in the cytoplasm.

N-terminal part (1-266) has GTPase activity. Required for proper cellular localization.

The pG1 pseudoGTPase domain does not bind GTP.