HUMAN GENES ENCODING THE VOLTAGE-DEPENDENT ANION CHANNEL (VDAC) OF THE OUTER MITOCHONDRIAL-MEMBRANE - MAPPING AND IDENTIFICATION OF 2 NEW ISOFORMS

The voltage-dependent anion channel of the mitochondrial outer membran e (VDAC) is a small, abundant pore-forming protein found in the outer membranes of all eukaryotic mitochondria. The VDAC protein is believed to form the major pathway for movement of adenine nucleotides through the outer membrane and to be the mitochondrial binding site for hexok inase and glycerol kinase. Previous studies have indicated that at lea st two human VDAC isoforms are expressed. Here, we report the mapping of VDAC 1 to the X chromosome in the interval Xq13-q21 and VDAC2 to ch romosome 21 by polymerase chain reaction and restriction analysis of a human/rodent somatic cell mapping panel. In the process of mapping th ese genes, we identified and mapped two additional sequences highly ho mologous to VDAC1. VDAC3 maps to chromosome 12 and VDAC4 maps to chrom osome 1. The locations of VDAC1 and VDAC4 have been confirmed by fluor escence in situ hybridization analysis. Future studies will be aimed a t defining the specific physiological role of each member of this fami ly of channel proteins. (C) 1994 Academic Press, Inc.