Disease relevance of AP2B1

• Characterization of a new member of the human beta-adaptin gene family from chromosome 22q12, a candidate meningioma gene [1].

High impact information on AP2B1

• A coat subunit of Golgi-derived non-clathrin-coated vesicles with homology to the clathrin-coated vesicle coat protein beta-adaptin [2].
• In vitro binding of the asialoglycoprotein receptor to the beta adaptin of plasma membrane coated vesicles [3].
• Partial proteolysis of the AP-2 preparation followed by the receptor binding assay revealed that the aminoterminal domain of the beta adaptin contains the binding site for receptors [3].
• When fractionated by gel electrophoresis in the presence of urea, the ASGP receptor binding polypeptide displayed a characteristic shift in electrophoretic mobility identifying it as the beta adaptin [3].
• ATM binds to beta-adaptin in cytoplasmic vesicles [4].

Biological context of AP2B1

• Chromosome localization of human genes for clathrin adaptor polypeptides AP2 beta and AP50 and the clathrin-binding protein, VCP [5].
• Our data describing the association of ATM with beta-adaptin in vesicles indicate that ATM may play a role in intracellular vesicle and/or protein transport mechanisms [4].
• Protein kinase C activates human lipocalin-type prostaglandin D synthase gene expression through de-repression of notch-HES signaling and enhancement of AP-2 beta function in brain-derived TE671 cells [6].
• beta-adaptin: Key molecule for microglial scavenger receptor function under oxidative stress [7].

Anatomical context of AP2B1

• Differential expression experiments of beta-adaptin, alpha-adaptin, SR-AI, and SR-BI in RAW (macrophages) and EOC (microglia) cells were performed according to dosage and exposure time to amyloid-beta [7].
• Expression of a novel beta adaptin subunit mRNA splice variant in human testes [8].

Regulatory relationships of AP2B1

• We identify a crucial tyrosine residue in the ear domain of beta2-adaptin and show in vitro that the phosphorylation of this site regulates the interaction between beta-arrestin and beta2-adaptin [9].

Other interactions of AP2B1

• We have determined human chromosomal locations of genes for a large AP2 beta (CLAPB1) and a medium (CLAPM1) AP subunit and of a novel clathrin-binding protein, VCP, that binds clathrin simultaneously with APs [5].
• The interaction between ATM and beta-adaptin was confirmed in vitro, and coimmunoprecipitation and colocalization studies show that the proteins also associate in vivo [4].
• ATM also interacts in vitro with beta-NAP, a neuronal-specific beta-adaptin homolog that was identified as an autoantigen in a patient with cerebellar degeneration [4].
• Like AP180, auxilin also directly interacts with the ear domain of beta-adaptin [10].

Analytical, diagnostic and therapeutic context of AP2B1

• The gene for the CLAPB1 large subunit was mapped to 17q11.2-q12 by PCR amplification of an AP2 beta fragment from a panel of rodent-human hybrid DNAs [5].
• Under these conditions, RT-PCR assays show that beta-adaptin mRNA is normally synthesized, reason why protein translation or protein structure of beta-adaptin might be altered [7].

References