Anti-Alpha-Adaptin AP2A1 Antibody (Monoclonal, 100/2)

Alpha Adaptin, also known as adaptor related protein complex, alpha 1 subunit. The alpha adaptins are exclusively found in the endocytic coated vesicles. Huntingtin-interacting protein 1 (HIP1) is enriched in membrane-containing cell fractions and has been implicated in vesicle trafficking. Waelter et al. (2001) identified 3 HIP1-associated proteins, clathrin heavy chain (CLTC) and alpha-adaptin A and C. Coat proteins of approximately 100-kD (adaptins) are components of the adaptor complexes which link clathrin to receptors in coated vesicles. The alpha-adaptins separate into two bands on SDS gels.

AP2A1: Isoform A expressed in forebrain, skeletalmuscle, spinal cord, cerebellum, salivary gland, heart and colon.Isoform B is widely expressed in tissues and also in breast cancerand in prostate carcinoma cells.

AP2A1: Component of the adaptor protein complex 2 (AP-2) .Adaptor protein complexes function in protein transport viatransport vesicles in different membrane traffic pathways. Adaptorprotein complexes are vesicle coat components and appear to beinvolved in cargo selection and vesicle formation. AP-2 isinvolved in clathrin-dependent endocytosis in which cargo proteinsare incorporated into vesicles surrounded by clathrin (clathrin-coated vesicles, CCVs) which are destined for fusion with theearly endosome. The clathrin lattice serves as a mechanicalscaffold but is itself unable to bind ly to membranecomponents. Clathrin-associated adaptor protein (AP) complexeswhich can bind ly to both the clathrin lattice and to thelipid and protein components of membranes are considered to be themajor clathrin adaptors contributing the CCV formation. AP-2 alsoserves as a cargo receptor to selectively sort the membraneproteins involved in receptor-mediated endocytosis. AP-2 seems toplay a role in the recycling of synaptic vesicle membranes fromthe presynaptic surface. AP-2 recognizes Y-X-X-[FILMV] (Y-X-X-Phi) and [ED]-X-X-X-L-[LI] endocytosis signal motifs within thecytosolic tails of transmembrane cargo molecules. AP-2 may alsoplay a role in maintaining normal post-endocytic traffickingthrough the ARF6-regulated, non-clathrin pathway. The AP-2 alphasubunit binds polyphosphoinositide-containing lipids, positioningAP-2 on the membrane. The AP-2 alpha subunit acts via its C-terminal appendage domain as a scaffolding platform for endocyticaccessory proteins. The AP-2 alpha and AP-2 sigma subunits arethought to contribute to the recognition of the [ED]-X-X-X-L-[LI]motif (By similarity) .

1. Robinson, M. S. : Cloning of cDNAs encoding two related 100-kD coated vesicle proteins (alpha-adaptins) . J. Cell Biol. 108: 833-42, 1989. 2. Waelter, S.; Scherzinger, E.; Hasenbank, R.; Nordhoff, E.; Lurz, R.; Goehler, H.; Gauss, C.; Sathasivam, K.; Bates, G. P.; Lehrach, H.; Wanker, E. E. : The huntingtin interacting protein HIP1 is a clathrin and alpha-adaptin-binding protein involved in receptor-mediated endocytosis. Hum. Molec. Genet. 10: 1807-1817, 2001.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.

AP2A1: Cell membrane Membrane, coated pit Note: AP-2 appearsto be excluded from internalizing CCVs and to disengage from sitesof endocytosis seconds before internalization of the nascent CCV.|Ap2a1: Cell membrane Membrane, coated pit Note: AP-2 appearsto be excluded from internalizing CCVs and to disengage from sitesof endocytosis seconds before internalization of the nascent CCV.