The Arabidopsis thaliana plasma membrane H(+)-ATPase multigene family. Genomic sequence and expression of a third isoform.

摘要: The plasma membrane of higher plants contains a H(+)-ATPase as its major ion pump. This enzyme belongs to the P-type family cation-translocating enzymes and generates proton-motive force that drives solute uptake across membrane. In Arabidopsis thaliana is encoded by multigene (Harper, J. F., Surowy, T. K., Sussman, M. R. (1989) Proc. Natl. Acad. Sci. U. S. A. 86, 1234-1238). complete genomic sequence third isoform (referred AHA2) presented here, predicted protein compared with previously published AHA1, AHA3, tobacco Nicotiana plumbaginifolia NP1 isoforms. AHA2 gene most similar proteins containing 95% amino acid identity. mRNA start site 5'-untranslated for were determined from cDNA amplified polymerase chain reaction. 5' region 23-base pair (bp) polypyrimidine short upstream reading frame. comparison 16 introns reported in missing one intron second C-terminal coding region. An unusually large (greater than 1000 bp) present at beginning both AHA3. 3'-untranslated AHA1 but not there 65-bp 85% identity shorter 16-bp harboring an unusual putative poly(A) addition signal (dTTTGAAGAAACAAGGC). Northern blot analysis indicates relative total cellular RNA expressed significantly levels root tissue shoot tissue.