Enables GTPase activating protein binding activity. Acts upstream of or within several processes, including positive regulation of GTPase activity; positive regulation of phagocytosis; and protein localization to cell cortex. Predicted to be located in P-body; cytosol; and nucleoplasm. Is expressed in several structures, including alimentary system; brain; cartilage; cranium; and reproductive system. Orthologous to human MEX3B (mex-3 RNA binding family member B). [provided by Alliance of Genome Resources, Apr 2022]