LOCALIZATION OF 2 GENES ENCODING PLASMA-MEMBRANE CA2+ ATPASES ISOFORM-2 (ATP2B2) AND ISOFORM-3 (ATP2B3) TO HUMAN-CHROMOSOME-3P26-]P25 AND HUMAN-CHROMOSOME-XQ28, RESPECTIVELY

The plasma membrane Ca2+ ATPases (PMCA) represent a highly conserved, widely dispersed, multigene family in eukaryotes consisting of at least four functional genes. The genes for PMCA isoforms 1 and 4 (ATP2B1 and ATP2B4) have been previously localized to human chromosomes 12q21 --> q23 and 1q25 --> q32, respectively. Based upon results of fluorescence in situ hybridization (FISH), analysis of somatic cell hybrids, and genetic linkage analyses, we now report localization of ATP2B3 (PMCA isoform 3) to human chromosome Xq28, and confirm the recent localization of ATP2B2 (PMCA isoform 2) to chromosome 3p26 --> p25. In contrast to ATP2B1 and ATP2B4, recent studies have suggested tissue specific regulation of expression of both ATP2B2 and ATP2B3 particularly in the nervous system. The genes for several neurological and neuromuscular diseases have been assigned to the distal portion of Xq, and ATP2B3 is a candidate gene for these diseases.