ARHGAP11B (Rho GTPase Activating Protein 11B)

ARHGAP11B is a partial duplication of the ARHFAP11A gene that arose after the human lineage diverged from the Pan genus but prior to the split with Neandertal and Denisovan. ARHGAPs are Rho guanosine triphosphatase–activating proteins activate Rho GTPases and are important in regulating a broad range of cellular signaling processes. ARHGAP11B contains most of the ARHGAP11A GAP-domain followed by a unique C-terminal sequence, however it is functionally distinct not displaying RhoA/Rho- kinase activity. Overexpression in mouse neocortex induces increased basal progenitor generation, thickening of the subventricular zone, and induction of cortical folding. These changes are cause by ARHGAP11B inducing basal progenitor cells to self-replicate. These findings make ARHGAP11B a likely candidate in the evolutionary expansion of the human neocortex.