Acts as an assembly platform for Rho protein signaling complexes. Limits guanine nucleotide exchange activity of MCF2L toward RHOA, which results in an inhibition of both its transcriptional activation ability and its transforming activity. Does not inhibit activity of MCF2L toward CDC42, or activity of MCF2 toward either RHOA or CDC42 (By similarity). May be involved in cell cycle regulation. Interacts with MCF2L. May interact with MCF2, ARHGEF1, BCR, VAV1 and FGD1, but not with TIAM1. Interacts with GTP-bound CDC42 and SRC (By similarity). Belongs to the CCPG1 family. Truncated N-terminus. Contaminating sequence. Potential poly-A sequence. Contaminating sequence. Potential poly-A sequence.