Four subunit a isoforms of Caenorhabditis elegans vacuolar H+-ATPase - Cell-specific expression during development

Citation
T. Oka et al., Four subunit a isoforms of Caenorhabditis elegans vacuolar H+-ATPase - Cell-specific expression during development, J BIOL CHEM, 276(35), 2001, pp. 33079-33085
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
0021-9258 → ACNP
Volume
276
Issue
35
Year of publication
2001
Pages
33079 - 33085
Database
ISI
SICI code
0021-9258(20010831)276:35<33079:FSAIOC>2.0.ZU;2-V
Abstract
We have identified four genes (vha-5, vha-6, vha-7, and unc-32) coding for vacuolar-type proton-translocating ATPase (V-ATPase) subunit a in Caenorhab ditis elegans, the first example of four distinct isoforms in eukaryotes. T heir products had nine putative transmembrane regions, exhibited 43-60% ide ntity and 62-84% similarity with the bovine subunit al isoform, and retaine d 11 amino acid residues essential for yeast V-ATPase activity (Leng, X. H. , Manolson, M. F., and Forgac, M. (1998) J. Biol. Chem. 273, 6717-6723). Th e similarities, together with the results of immunoprecipitation, suggest t hat these isoforms are components of V-ATPase. Transgenic and immunofluores cence analyses revealed that these genes were strongly expressed in distinc t cells; vha-5 was strongly expressed in an H-shaped excretory cell, vha-6 was strongly expressed in intestine, vha-7 was strongly expressed in hypode rmis, and unc-32 was strongly expressed in nerve cells. Furthermore, the vh a-7 and unc-32 genes were also expressed in the uteri of hermaphrodites. RN A interference analysis showed that the double-stranded RNA for unc-32 caus ed embryonic lethality similar to that seen with other subunit genes (vha-1 , vha-4, and vha-11) (Oka, T., and Futai, M. (2000) J. Biol. Chem. 275, 295 56-29561). The progenies of worms injected with the vha-5 or vha-6 double-s tranded RNA became died at a specific larval stage, whereas the vha-7 doubl e-stranded RNA showed no effect on development. These results suggest that V-ATPases with these isoforms generate acidic compartments essential for wo rm development in a cell-specific manner.