AP-3 complex subunit beta-2
Developmental stage
Expressed from early in development through adulthood.
Function
Subunit of non-clathrin- and clathrin-associated adaptor protein complex 3 (AP-3) that plays a role in protein sorting in the late-Golgi/trans-Golgi network (TGN) and/or endosomes. The AP complexes mediate both the recruitment of clathrin to membranes and the recognition of sorting signals within the cytosolic tails of transmembrane cargo molecules. AP-3 appears to be involved in the sorting of a subset of transmembrane proteins targeted to lysosomes and lysosome-related organelles. In concert with the BLOC-1 complex, AP-3 is required to target cargos into vesicles assembled at cell bodies for delivery into neurites and nerve terminals.
Involvement in disease
Developmental and epileptic encephalopathy 48
DEE48
A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE48 is an autosomal recessive form characterized by onset of seizures in the first year of life. Affected individuals manifest global developmental delay, intellectual disability, absent speech, and poor, if any, motor development.
None
The disease may be caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the adaptor complexes large subunit family.
Tissue Specificity
Isoform 1 expression is specific to nervous system. Expressed in nerve terminal and cell body, and is associated with nerve-terminal vesicles. Expression seen in Purkinje cells, cortical neurons, neuroectodermal tumors and graded in cerebral cortex (deeper layers exhibit stronger expression) (PubMed:1851215). Isoform 2 is expressed at high levels in brain and testis (PubMed:17453999).
Cellular localization
- Cytoplasmic vesicle
- Clathrin-coated vesicle membrane
- Peripheral membrane protein
- Cytoplasmic side
- Golgi apparatus
- Component of the coat surrounding the cytoplasmic face of coated vesicles located at the Golgi complex.
Alternative names
AP-3 complex subunit beta-2, Adaptor protein complex AP-3 subunit beta-2, Adaptor-related protein complex 3 subunit beta-2, Beta-3B-adaptin, Clathrin assembly protein complex 3 beta-2 large chain, Neuron-specific vesicle coat protein beta-NAP, AP3B2