AP2B1
AP2B1 (adaptor related protein complex 2 subunit beta 1; also ADTB2 and CLAPB1) is the beta large subunit of the AP-2 adaptor complex. It links clathrin to membrane cargo during clathrin-dependent endocytosis at the plasma membrane. Browse Assay Genie's current range of AP2B1 research reagents below, or read on for the biology behind the target.
AP2B1 is a component of the adaptor protein complex 2 (AP-2). Adaptor protein complexes act as vesicle coat components in membrane traffic and appear to be involved in cargo selection and vesicle formation. AP-2 drives clathrin-dependent endocytosis, in which cargo proteins are packaged into clathrin-coated vesicles destined for fusion with the early endosome. The clathrin lattice is a mechanical scaffold but cannot bind membrane components directly, so AP complexes, which bind both clathrin and the lipid and protein components of membranes, are considered the major clathrin adaptors in coated vesicle formation.
The AP-2 beta subunit binds to clathrin heavy chain and promotes clathrin lattice assembly. Its C-terminal appendage domain serves as a scaffolding platform for endocytic accessory proteins, and at least some clathrin-associated sorting proteins are recognised through a [DE]-X(1,2)-F-X-X-[FL]-X-X-X-R motif. Clathrin displaces at least some of these proteins from AP2B1, which can then probably be positioned for further coat assembly. AP-2 also acts as a cargo receptor, recognising Y-X-X-Phi and [ED]-X-X-X-L-[LI] endocytosis signal motifs in the cytosolic tails of transmembrane cargo, and so selectively sorts membrane proteins during receptor-mediated endocytosis.
Functions reported for AP-2 include recycling of synaptic vesicle membranes from the presynaptic surface, maintaining post-endocytic trafficking through the ARF6-regulated, non-clathrin pathway, and endocytosis of ADAM10 during long-term potentiation in hippocampal neurons. The AP2B1 gene encodes one of two large chain components of the complex, found on the cytoplasmic face of coated vesicles at the plasma membrane, and two transcript variants encoding different isoforms have been described. The protein belongs to the adaptor complexes large subunit family, and the gene is placed in the HGNC adaptor related protein complex 2 group.
AP2B1 binds clathrin heavy chain and promotes lattice assembly, making it a core subunit for studying how coated vesicles form at the plasma membrane.
AP-2 recognises Y-X-X-Phi and acidic dileucine-type signals in cargo tails, a basis for studying selective sorting in receptor-mediated endocytosis.
AP-2 appears to contribute to recycling of synaptic vesicle membranes from the presynaptic surface, linking AP2B1 to neuronal membrane traffic research.
The beta appendage domain acts as a scaffold for accessory proteins and clathrin-associated sorting proteins, useful for studying coat assembly.
AP2B1 is the beta subunit of the AP-2 adaptor complex. It binds clathrin heavy chain to promote lattice assembly and, through its appendage domain, scaffolds endocytic accessory proteins. This supports cargo selection and clathrin-coated vesicle formation during clathrin-dependent endocytosis.
AP2B1 is also known as ADTB2 and CLAPB1, and UniProt names the protein AP-2 complex subunit beta. Earlier HGNC names include adaptor related protein complex 2 beta 1 subunit. NCBI Gene reports two transcript variants encoding different isoforms.
Orthologs of the human gene are annotated in mouse and rat, both named Ap2b1. The protein belongs to the adaptor complexes large subunit family. Check the datasheet of any product for its validated reactivity.
Other adaptor protein complex subunits and trafficking-related targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P63010; product specifications from Assay Genie datasheets.