Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied a mitochondrial inorganic pyrophosphatase (PPase) in the yeast Saccharomyces cerevisiae. The uncoupler FCCP (carbonyl cyanide p-trifluoromethoxyphenylhydrazone) and the ionophores valinomycin and nigericin stimulate the PPase activity of repeatedly washed yeast mitochondria 2-3-fold. We have previously cloned a yeast gene, PPA2, encoding the catalytic subunit of a mitochondrial PPase. Uncouplers stimulate the PPase activity several-fold in mitochondria from both cells that overexpress PPA2 from a high copy number plasmid and cells with normal expression. These results indicate that the PPA2 polypeptide functions as an energy linked and membrane associated PPase. The stimulation of mitochondrial PPase activity by FCCP, but not by valinomycin and nigericin, was greatly enhanced by the presence of DTT. The antibiotics Dio-9, equisetin and the F0F1-ATPase inhibitor oligomycin also increase mitochondrial PPase activity several fold. This stimulation is much higher, whereas basal PPase activity is lower, in isotonic than in hypotonic solution, which indicates that intact membranes are a prerequisite for maximal effects.
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PMID:Characterization of a mitochondrial inorganic pyrophosphatase in Saccharomyces cerevisiae. 130 54

Vegetative-bud dormancy in peach (Prunus persica L. Batsch) trees is known to be correlated, at least partially, with properties of the underlying bud tissues during winter. Variations in the activity and amount of plasma-membrane H -ATPase were observed. A full-length cDNA, PPA2 (Prunus persica H+-ATPase 2) and three partial cDNAs (PPA1, PPA3 and PPA4) for the plasma-membrane H+-ATPase from peach trees were isolated by reverse transcription (RT)-coupled rapid amplification of cDNA ends (RACE) polymerase chain reaction (PCR). The accumulation of plasma membrane H+-ATPase transcripts was then studied in vegetative buds during dormancy and breaking of dormancy. Competitive RT-PCR analysis revealed that, during dormancy, the plasma membrane H+-ATPase transcripts were higher in the tissues underlying the buds than in the buds themselves. After dormancy release, the level of PPA1, 2, 3 mRNA increased, whereas the level of PPA4 decreased in the buds. When trees were kept in a greenhouse (i.e. sheltered from chilling), no accumulation of PPA mRNA could be detected. These results suggest that there is a differential accumulation of H+-ATPase mRNA between the bud and the underlying bud tissues during dormancy, and that chilling could act as a decisive factor.
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PMID:Differential expression of four members of the H+-ATPase gene family during dormancy of vegetative buds of peach trees. 1152 20