Binds and exchanges GTP and GDP. Binds and modulates the activation of POU4F1 as gene expression regulator. GTP + H2O = GDP + H(+) + phosphate Alternates between an inactive form bound to GDP and an active form bound to GTP. Interacts with PLXNB3 (By similarity). Interacts with AFDN, the C-terminal domain of RALGDS and RLF, but not with RIN1 and PIK3CA. RLF binds exclusively to the active GTP-bound form. Binds calmodulin. Interacts with POU4F1 (via N-terminus); the interaction controls POU4F1 transactivation activity on some neuronal target genes (PubMed:12934100). Colocalizes with PLXNB3 at the plasma membrane. Expressed in ganglion cell layer (GCL), inner plexiform layer (IPL) and inner nuclear layer (INL) of the retina. Expressed in retinal ganglion cells (RGCs). Expressed in horizontal, bipolar and amacrine cells, but not Mueller glia, of the INL (at protein level). Neuron-specific (PubMed:8824319). Expressed in ganglion cell layer (GCL) and inner plexiform layer (IPL) (PubMed:23805044). Expressed weakly in ganglion cell layer (GCL) and inner neuroblastic layer (NBL) of the embryonic retina at 15.5 dpc. Expression increases progressively in the retina from new borns at postnatal day 2 (P2), P5, P15 to 8 week-old adult (at protein level). Shows rapid uncatalyzed guanine nucleotide dissociation rates, which are much faster than those of most Ras subfamily members. Belongs to the small GTPase superfamily. Ras family. Truncated N-terminus.