Brain Enriched Guanylate Kinase Associated Protein (BEGAIN)

BEGAIN is specifically expressed in brain and enriched in the PSD fraction. BEGAIN is Triton X-100-soluble in the transfected cells but is recruited to the Triton X-100-insoluble fraction by SAPAP when coexpressed with PSD-95/SAP90. BEGAIN may be a novel PSD component associated with the core complex of PSD-95/SAP90 and SAPAP.

BEGAIN is expressed in neurons and rather enriched at synaptic junctions. BEGAIN may be involved also in the organization of the components of synaptic junctions. To confirm the interaction of BEGAIN with PSD-95/SAP90, BEGAIN was immunoprecipitated from the crude synaptosome fraction. PSD-95/SAP90 was coprecipitated with BEGAIN as well as with SAPAP.