The E subunit of vacuolar H(+)-ATPase localizes close to the centromere on human chromosome 22.
As part of a general effort to identify new genes mapping to disease-associated regions of human chromosome 22, we have isolated heterogeneous nuclear RNA from somatic cell hybrids selected for their chromosome 22 content. Inter-Alu PCR amplification yielded a series of human DNA fragments which all detected evolutionarily-conserved sequences. The centromere-most gene fragment candidate, XEN61, was shown to lie centromeric to the chromosome 22 breakpoint in the X/22-33-11TG somatic cell hybrid. This region, which is still devoid of characterized genes, overlaps with the critical region for the cat eye syndrome (CES), a developmental disorder associated with chromosomal duplication within 22pter-q11.2. Gene dosage analysis performed on DNA from six CES patients consistently revealed the presence of four copies of XEN61. A fetal brain cDNA clone, 61EW, was identified with XEN61 and entirely sequenced. The deduced protein is the E subunit of vacuolar H(+)-ATPase. This 31 KDa component of a proton pump is essential in eukaryotic cells as it both controls acidification of the vacuolar system and provides it with its main protonmotive force. RT-PCR experiments using oligonucleotides designed from the 61EW cDNA sequence indicated that the corresponding messenger is widely transcribed.
Baud
V
V
Laboratoire de Biologie des Tumeurs Humaines, CNRS URA 1156, Institut Gustave Roussy, Vilejuif, France.
Mears
A J
AJ
Lamour
V
V
Scamps
C
C
Duncan
A M
AM
McDermid
H E
HE
Lipinski
M
M
D001483:Base Sequence; D002503:Centromere; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22; D005796:Genes; D005819:Genetic Markers; D006801:Humans; D006822:Hybrid Cells; D008969:Molecular Sequence Data; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics*; D012332:RNA, Heterogeneous Nuclear / Q000235:genetics; D014617:Vacuoles / Q000201:enzymology*
D005819:Genetic Markers; D012332:RNA, Heterogeneous Nuclear; D006180:Proton-Translocating ATPases