The multigene family of the tobacco hornworm V-ATPase: novel subunits a, C, D, H, and putative isoforms.
The plasma membrane V-ATPase from Manduca sexta (Lepidoptera, Sphingidae) larval midgut is composed of at least 12 subunits, eight of which have already been identified molecularly [Wieczorek et al., J. Bioenerg. Biomembr. 31 (1999) 67-74]. Here we report primary sequences of subunits C, D, H and a, which previously had not been identified in insects. Expression of recombinant proteins, immunostaining and protein sequencing demonstrated that the corresponding proteins are subunits of the Manduca V-ATPase. Genomic Southern blot analysis indicated the existence of multiple genes encoding subunits G, a, c, d and e. Moreover, multiple transcripts were detected in Northern blots from midgut poly(A) RNA for subunits B, G, c and d. Thus, these polypeptides appear to exist as multiple isoforms that could be expressed either in different tissues or at distinct locations within a cell. By contrast subunits A, C, D, E, F and H appear to be encoded by single transcripts and therefore should be present in any Manduca V-ATPase, independent of its subcellular or cell specific origin.
Merzendorfer
H
H
Department of Biology, University of Osnabrück, Germany.
Reineke
S
S
Zhao
X F
XF
Jacobmeier
B
B
Harvey
W R
WR
Wieczorek
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D017344:Genes, Insect; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics; D018402:Manduca / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D020836:Protein Structure, Quaternary; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D025262:Vacuolar Proton-Translocating ATPases
D017931:DNA Primers; D018076:DNA, Complementary; D007527:Isoenzymes; D025262:Vacuolar Proton-Translocating ATPases; D006180:Proton-Translocating ATPases