Mitochondrial pyruvate dehydrogenase. Molecular cloning of the E1 alpha subunit and expression analysis.
A polymerase chain reaction-based approach was used to isolate cDNA clones encoding the E1 alpha subunit of the mitochondrial pyruvate dehydrogenase from higher plants. Putative full-length clones were identified on the basis of similarity to E1 alpha sequences from nonplant sources. Southern blot analysis revealed a small family of genes in potato (Solanum tuberosum L.), whereas in cucumber (Cucumis sativus) there are only one or two genes. Tissue-specific variation in the relative amounts of E1 alpha mRNA was observed in northern blot analysis of different potato tissues, with the highest steady-state transcript levels found in floral tissue. Measurement of pyruvate dehydrogenase activity in cucumber cotyledons showed that there is a transient increase to a maximum at 4 to 5 d postimbibition. Western blot analysis revealed that the amount of E1 alpha protein also peaks at this time. Steady-state transcript levels in germinating cucumber cotyledons also show transient accumulation, peaking 2 d postimbibition. These data are consistent with regulation of E1 alpha at the level of transcription and/or mRNA stability in postgerminative cucumber cotyledons.
Grof
C P
CP
Department of Plant Sciences, University of Oxford, United Kingdom.
Winning
B M
BM
Scaysbrook
T P
TP
Hill
S A
SA
Leaver
C J
CJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018628:Gene Dosage; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D011768:Pyruvate Dehydrogenase Complex / Q000096:biosynthesis / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics*
D018076:DNA, Complementary; D011768:Pyruvate Dehydrogenase Complex