Enables SH3 domain binding activity. Predicted to be involved in negative regulation of SNARE complex assembly; negative regulation of short-term synaptic potentiation; and synaptic vesicle exocytosis. Predicted to act upstream of or within neuromuscular process controlling posture. Located in neuron projection. Human ortholog(s) of this gene implicated in benign familial neonatal epilepsy and episodic kinesigenic dyskinesia 1. Orthologous to human PRRT2 (proline rich transmembrane protein 2). [provided by Alliance of Genome Resources, Apr 2022]