Adaptor-related protein complex 3 subunit sigma-2 (AP3S2)

Adaptor-related protein complex 3 subunit sigma-2 (AP3S2) is a protein-coding gene product and a component of the AP-3 heterotetrameric protein complex[3][1]. This complex is composed of two large adaptins (delta [AP3D1] and beta [AP3B1 or AP3B2]), a medium subunit (mu), and a small subunit (sigma). AP3S2 encodes the sigma-2 (σ3B) subunit, one of two sigma isoforms in the AP-3 complex. AP-3 functions in vesicle formation at the trans-Golgi network by mediating intracellular sorting and trafficking of specific cargos, particularly for lysosomes and lysosome-related organelles[1][2][3]. In neurons, it is critical for synaptic vesicle biogenesis, axonal and dendritic cargo delivery, and the function of specialized organelles such as melanosomes and platelet dense bodies[2][3]. Mutations in AP3S2 or other AP-3 subunits can result in neurodevelopmental disorders with neurological and pigmentation phenotypes, reflecting its pivotal role in cellular protein sorting and trafficking[3][2][1]. There is no current evidence indicating that AP3S2 is a direct therapeutic target, nor are specific drugs, mechanisms of action, or biomarkers directly associated with this subunit.

Other names

AP-3 complex subunit sigma-2AP3S2Sigma3B-adaptinsigma3bAP-3 complex subunit sigma-3Badaptor-related protein complex 3 subunit sigma-2Sigma-3B-adaptinSigma-adaptin 3bAP3S3clathrin-associated/assembly/adaptor protein, small 422-kDsigma-3B-adaptinsigma-adaptin 3b