Chromosome Localization of Human Genes for Clathrin Adaptor Polypeptides AP2β and AP50 and the Clathrin-Binding Protein, VCP

Clathrin-coated vesicles, involved in endocytosis and Golgi processing, have a surface lattice containing clathrin triskelia and stoichiometric amounts of additional components termed "assembly proteins," or APs. The AP form at the plasma membrane, AP2, is composed of two large subunits of 100-115 kDa, denoted AP2α and AP2β, a medium chain of 50 kDa, designated AP50, and a small chain. We have determined human chromosomal locations of genes for a large AP2β (CLAPB1) and a medium (CLAPM1) AP subunit and of a novel clathrin-binding protein, VCP, that binds clathrin simultaneously with APs. Chromosomalin situhybridization of a human genomic clone demonstrated that the CLAPM1 gene mapped to chromosome region 3q28. The gene for the CLAPB1 large subunit was mapped to 17q11.2-q12 by PCR amplification of an AP2β fragment from a panel of rodent-human hybrid DNAs. To map the human VCP sequence, a human-specific probe was made by RT-PCR of human mRNA using oligonucleotide primers from conserved regions of the porcine sequence. The amplified human fragment served as probe on Southern blots of hybrid DNAs to determine that the human VCP locus maps to chromosome region 9pter-q34.