Anti-AP2B1 Antibody Picoband® Fluoro488 Conjugated

AP-2 complex subunit beta is a protein that in humans is encoded by the AP2B1 gene. It is mapped to 17q12. The protein encoded by this gene is one of two large chain components of the assembly protein complex 2, which serves to link clathrin to receptors in coated vesicles. The encoded protein is found on the cytoplasmic face of coated vesicles in the plasma membrane. Two transcript variants encoding different isoforms have been found for this gene.

AP-2 complex subunit beta; AP105B; Adaptor protein complex AP-2 subunit beta; Adaptor-related protein complex 2 subunit beta; Beta-2-adaptin; Beta-adaptin; Clathrin assembly protein complex 2 beta large chain; Plasma membrane adaptor HA2/AP2 adaptin beta subunit; AP2B1; ADTB2, CLAPB1

E. coli-derived human AP2B1 recombinant protein (Position: Q311-R522) . Human AP2B1 shares 100% amino acid (aa) sequence identity with both mouse and rat AP2B1.

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 ly to membrane components. Clathrin-associated adaptor protein (AP) complexes which can bind ly 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 beta subunit acts via its C-terminal appendage domain as a scaffolding platform for endocytic accessory proteins; at least some clathrin- associated sorting proteins (CLASPs) are recognized by their [DE]- X (1,2) -F-X-X-[FL]-X-X-X-R motif. The AP-2 beta subunit binds to clathrin heavy chain, promoting clathrin lattice assembly; clathrin displaces at least some CLASPs from AP2B1 which probably then can be positioned for further coat assembly. .

1. Entrez Gene: AP2B1 adaptor-related protein complex 2, beta 1 subunit. 2. Druck T, Gu Y, Prabhala G, Cannizzaro LA, Park SH, Huebner K, Keen JH (Nov 1995) . Chromosome localization of human genes for clathrin adaptor polypeptides AP2 beta and AP50 and the clathrin-binding protein, VCP. Genomics. 30 (1) : 94–7. 3. Gallusser A, Kirchhausen T (Dec 1993) . The beta 1 and beta 2 subunits of the AP complexes are the clathrin coat assembly components. The EMBO Journal. 12 (13) : 5237–44.

Cell membrane . Membrane, coated pit ; Peripheral membrane protein ; Cytoplasmic side . AP-2 appears to be excluded from internalizing CCVs and to disengage from sites of endocytosis seconds before internalization of the nascent CCV.