Enables SH2 domain binding activity and identical protein binding activity. Involved in modulation of chemical synaptic transmission and synaptic vesicle endocytosis. Acts upstream of or within cellular response to organic substance. Located in several cellular components, including neuromuscular junction; presynaptic membrane; and synaptic vesicle membrane. Is active in Schaffer collateral - CA1 synapse. Is expressed in diaphragm; gut; nervous system; sensory organ; and skeletal muscle. Human ortholog(s) of this gene implicated in non-syndromic X-linked intellectual disability 96. Orthologous to human SYP (synaptophysin). [provided by Alliance of Genome Resources, Apr 2022]