ABSTRACT
Using conserved amino acid sequences for the design of oligonucleotide primers, we isolated cDNA clones for two subunits of the V-ATPase from the midgut and Malpighian tubules of Aedes aegypti larvae. The 3.1 kb cDNA of the A subunit of the peripheral catalytic V1 sector codes for a protein of 68.6 kDa. The protein contains conserved motifs, including an ATP/GTP binding site, found in all other A subunits. Southern analysis using the A subunit as a probe suggests the presence of only a single copy of gene in the Aedes aegypti. The 0.85 kb cDNA of the c subunit of the membrane H+ conducting V0 sector codes for a protein of kDa. This protein has four transmembrane domains and contains a conserved glutamic acid that serves as the binding site for dicyclohexylcarbodiimide. Southern analysis using the c subunit as a probe suggests the presence of more than one related gene in the genome of Aedes aegypti. Pileup analysis of various A and c subunits shows that these subunits fall into distinct clusters, including one in which all arthropod proteins are clustered.
Subject(s)
Aedes/genetics , Malpighian Tubules/enzymology , Proton-Translocating ATPases/genetics , Vacuolar Proton-Translocating ATPases , Aedes/embryology , Aedes/enzymology , Amino Acid Sequence , Animals , Base Sequence , DNA, Complementary , Larva/enzymology , Molecular Sequence Data , Species SpecificityABSTRACT
The Drosophila transient receptor potential (trp) gene and its homologue, trpl, have been suggested to mediate calcium entry during the insect's phototransduction process. We isolated a human cDNA, human trp-1 (Htrp-1), encoding a polypeptide of 793 amino acids that is 37% identical (62% similar) to Drosophila trp and trpl. Northern analysis showed that the Htrp-1 transcript is approximately 5.5 kb and expressed in most human tissues, with higher amounts in ovary, testis, heart, and brain. Isolation of Htrp-1 suggests that a trp-type protein is present in mammals and should provide a useful tool in studying calcium-depletion induced calcium influx processes.