Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.3.1 (citrate synthase)
 4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A small RNA encoded within the nucleus of yeast and mammalian cells is an essential subunit of a mitochondrial RNA-processing endonuclease (RNase MRP) that generates primers for mitochondrial DNA (mtDNA) replication. We examined expression of MRP-RNA in specialized subtypes of mammalian striated muscles that differ markedly in respiratory activity and in muscles subjected to chronic stimulation via the motor nerve, a potent stimulus to mitochondrial biogenesis. MRP-RNA was more abundant in mitochondria-rich cardiac and slow-twitch skeletal muscles than in glycolytic fast-twitch skeletal muscles. Forced contractile activity resulting from nerve stimulation increased expression of MRP-RNA by 3.5-fold within the first day and by 14-fold within 14 days. Changes in abundance of MRP-RNA preceded but otherwise occurred in parallel to changes in specific activity of citrate synthase, a marker of mitochondrial proliferation shown previously to correlate with mtDNA copy number in this model. Another small RNA (U1) also was induced transiently (1-3 days) by nerve stimulation, but such changes were not sustained and were of less magnitude (< 4-fold) than changes in MRP-RNA. These findings are consistent with the hypothesis that MRP-RNA may have a regulatory function with respect to mtDNA replication and mitochondrial biogenesis.
 ...
PMID:RNA subunit of mitochondrial RNA-processing enzyme is induced by contractile activity in striated muscle. 750 87

The transcripts of the citrate synthase-encoding gene (gltA) in Rickettsia prowazekii (Rp), an obligate intracellular parasitic bacterium, were analyzed by RNase protection (RP), primer extension (PE) and in vitro transcription assays. Analysis of the 5' end of the gltA mRNA by RP and PE assays revealed that there were two gltA mRNAs with the 5' ends located at 16 bp and 307 bp upstream from the gltA coding region. Since these two mRNAs might represent two species of mRNA transcribed from two different promoters or a single transcript that was processed to give two mRNAs, an in vitro transcription analysis with purified Rp RNA polymerase (RNAP) was performed to distinguish these two possibilities. Purified Rp RNAP catalyzed the formation of two transcripts initiated from the same nucleotides indicated by RP and PE. Sequence analysis identified Escherichia coli (Ec) promoter-like sequences immediately upstream from both transcription start points (tsp). The first promoter (promoter P1) had the core sequence TTCTAA-N17-TATACT, was 6 bp upstream from the tsp (base A) and was centered at 37 bp upstream from the coding region. The second promoter (promoter P2) had the core sequence ATGAAA-N17-TAAAGT, was 7 bp upstream from the tsp (base T) and was centered at 329 bp upstream from the coding region. This is the first demonstration of multiple promoters in this obligate intracellular parasite which has implications concerning transcriptional regulation.
 ...
PMID:The citrate synthase-encoding gene of Rickettsia prowazekii is controlled by two promoters. 755 59

RNAs of Rickettsia prowazekii, an obligate intracytoplasmic bacterium, have been identified and analyzed by an RNase protection assay. Total RNA, a mixture of host cell RNA and rickettsial RNA, was isolated from rickettsia-infected mouse L929 cells by the hot-phenol method. After hybridization with specific antisense RNA probes and digestion with RNase, the protected products were analyzed by electrophoresis and autoradiography. The results show that there is only one mRNA species for the ATP/ADP translocase gene (tlc) but two mRNA species for the citrate synthase gene (gltA). RNA half-lives were determined by measuring the RNA remaining after addition of rifampin. The half-lives of tlc mRNA, gltA mRNA I, and gltA mRNA II in R. prowazekii are 8.4 +/- 0.6, 12.3 +/- 1.3, and 20.5 +/- 1.8 min, respectively. However, the half-lives of tlc mRNA and gltA mRNA I in recombinant Escherichia coli strains are 2.9 +/- 0.1 and 1.4 +/- 0.1 min, respectively. The 16S rRNA in R. prowazekii was also examined and shown to be stable.
 ...
PMID:Identification of tlc and gltA mRNAs and determination of in situ RNA half-life in Rickettsia prowazekii. 769 26

We report the isolation of cDNA clones encoding the somatic form of the E1 alpha subunit of the pyruvate dehydrogenase complex of rat. The deduced amino acid sequence has 99.5, 98, and 97% identity, respectively, with the orthologous proteins of mouse, human, and pig and 98.5% identity with a rat E1 alpha sequence reported previously. The cDNAs isolated in this and earlier studies predict different E1 alpha subunit mRNA sizes and amino acid sequences. These differences have been investigated by PCR, northern blot hybridization, and RNase protection. We have used our E1 alpha cDNA, in conjunction with cDNA probes to the E1 beta, E2, and E3 catalytic subunits of rat pyruvate dehydrogenase complex and also to rat citrate synthase, to perform RNase protection assays of developing rat whole brain RNA. The results show a 2.5-fold increase in the concentration of each of the subunit mRNAs and a 1.2-fold increase in citrate synthase mRNA from late foetal stage to 5 days post partum. Thereafter, the mRNA levels remained constant. These data indicate that the respective six- and threefold increases in the amounts of pyruvate dehydrogenase complex and citrate synthase found to occur in rat brain between birth and adulthood are mediated principally by translational and/or posttranslational mechanisms.
 ...
PMID:The pyruvate dehydrogenase complex: cloning of the rat somatic E1 alpha subunit and its coordinate expression with the mRNAs for the E1 beta, E2, and E3 catalytic subunits in developing rat brain. 815 20