Ap-2 Complex Subunit Alpha-1 (AP2A1) Antibody – Rabbit Polyclonal

This gene encodes the alpha 1 adaptin subunit of the adaptor protein 2 (AP-2) complex found in clathrin coated vesicles. The AP-2 complex is a heterotetramer consisting of two large adaptins (alpha or beta), a medium adaptin (mu), and a small adaptin (sigma). The complex is part of the protein coat on the cytoplasmic face of coated vesicles which links clathrin to receptors in vesicles. Alternative splicing of this gene results in two transcript variants encoding two different isoforms. A third transcript variant has been described, but its full length nature has not been determined. [provided by RefSeq, Jul 2008]

AP2A1: Component of the adaptor protein complex 2 (AP-2). Adaptor protein complexes function in protein transport via transport vesicles in different membrane traffic pathways. Adaptor protein complexes are vesicle coat components and appear to be involved in cargo selection and vesicle formation. AP-2 is involved in clathrin-dependent endocytosis in which cargo proteins are incorporated into vesicles surrounded by clathrin (clathrin- coated vesicles, CCVs) which are destined for fusion with the early endosome. The clathrin lattice serves as a mechanical scaffold but is itself unable to bind directly to membrane components. Clathrin-associated adaptor protein (AP) complexes which can bind directly to both the clathrin lattice and to the lipid and protein components of membranes are considered to be the major clathrin adaptors contributing the CCV formation. AP-2 also serves as a cargo receptor to selectively sort the membrane proteins involved in receptor-mediated endocytosis. AP-2 seems to play a role in the recycling of synaptic vesicle membranes from the presynaptic surface. AP-2 recognizes Y-X-X-[FILMV] (Y-X-X-Phi) and [ED]-X-X-X-L-[LI] endocytosis signal motifs within the cytosolic tails of transmembrane cargo molecules. AP-2 may also play a role in maintaining normal post-endocytic trafficking through the ARF6-regulated, non-clathrin pathway. The AP-2 alpha subunit binds polyphosphoinositide-containing lipids, positioning AP-2 on the membrane. The AP-2 alpha subunit acts via its C- terminal appendage domain as a scaffolding platform for endocytic accessory proteins. The AP-2 alpha and AP-2 sigma subunits are thought to contribute to the recognition of the [ED]-X-X-X-L-[LI] motif. Belongs to the adaptor complexes large subunit family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Adaptor/scaffold; Vesicle

Chromosomal Location of Human Ortholog: 19q13.33

Cellular Component: AP-2 adaptor complex; apical plasma membrane; basolateral plasma membrane; clathrin coat of trans-Golgi network vesicle; cytosol; filopodium tip; membrane; plasma membrane

Molecular Function: protein binding; protein C-terminus binding; protein complex binding; protein kinase binding; protein transporter activity

Biological Process: antigen processing and presentation of exogenous peptide antigen via MHC class II; axon guidance; endocytosis; ephrin receptor signaling pathway; epidermal growth factor receptor signaling pathway; Golgi to endosome transport; intracellular protein transport; negative regulation of epidermal growth factor receptor signaling pathway; nerve growth factor receptor signaling pathway; regulation of defense response to virus by virus; synaptic transmission; viral reproduction