Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The plasmalemmal Ca(2+) adenosine triphosphatase (PMCA) is a key regulator of Ca(2+) efflux in vascular smooth muscle. In these studies we developed a real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) assay for assessing PMCA1 mRNA levels in rat primary cultured aortic myocytes. This assay detected fetal bovine serum-induced increases in PMCA1 mRNA (relative to 18S rRNA) 4, 8, and 24 h after stimulation. Early fetal bovine serum-induced increases in PMCA1 mRNA were insensitive to the Ca(2+) channel blockers nifedipine, flunarizine, and SKF-96365. These studies demonstrate the feasibility of real-time RT-PCR to assess mRNA levels of PMCA1 and illustrate dynamic regulation of this Ca(2+) pump isoform in rat primary cultured aortic myocytes.
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PMID:PMCA1 mRNA expression in rat aortic myocytes: a real-time RT-PCR study. 1102 85

The plasma membrane Ca(2+) pump is a key regulator of cytosolic free Ca(2+). Recent studies have demonstrated the dynamic expression of the plasma membrane Ca(2+) pump in a variety of cell types. Furthermore, alterations in plasma membrane calcium pump activity have now been implicated in human disease. In this study, the development of a technique to quantitatively assess mRNA expression of the human plasma membrane Ca(2+) ATPase (PMCA1) isoform of the plasma membrane Ca(2+) pump, using a real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) assay in a human breast epithelial cell line (MCF-7) is described. The sequences of the PMCA1 primers and probe for real-time RT-PCR are presented. The results also indicate that PMCA1 mRNA can be normalized to both 18S ribosomal RNA (18S rRNA) and human glyceraldehyde-3-phosphate dehydrogenase (hGAPDH) in MCF-7 cells. Real-time RT-PCR will be most useful in assessing PMCA1 mRNA expression in cases where only low amounts of RNA are available and/or when numerous samples must be assessed simultaneously.
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PMID:Development of a real-time RT-PCR assay for plasma membrane calcium ATPase isoform 1 (PMCA1) mRNA levels in a human breast epithelial cell line. 1139 29

The plasma membrane Ca(2+) ATPase (PMCA) is an essential regulator of free intracellular calcium. Recent studies have reported aberrant expression of the PMCA1 gene, a member of the PMCA family, in several cancer cell types. To elucidate the contribution of PMCA1 to oral carcinogenesis, we analyzed genetic and epigenetic changes and mRNA and protein expression in primary oral squamous cell carcinomas (OSCCs), oral premalignant lesions (OPLs), and OSCC-derived cell lines. The PMCA1 gene was epigenetically inactivated, but not mutated in the eight OSCC-derived cell lines tested. In clinical samples, frequent down-regulation of PMCA1 protein expression was found not only in primary OSCCs (43%), but also in OPLs (40%). Real-time quantitative reverse transcriptase-polymerase chain reaction data were consistent with the protein expression status. These results suggest that inactivation of the PMCA1 gene is a frequent and early event during oral carcinogenesis, and gene expression may be regulated by an epigenetic mechanism.
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PMID:Plasma membrane Ca2+ ATPase isoform 1 down-regulated in human oral cancer. 1632 33

Disruption of calcium homeostasis in epileptic cells is characterized by both short- and long-term perturbations of Ca(2+) buffering systems. Along with the Na(+)/Ca(2+) exchanger, the plasma membrane Ca(2+)-ATPase (PMCA) plays an important role in excitable cells. The involvement of PMCAs in epileptogenesis has primarily been studied in brief intervals after various stimuli; however, the specific contribution of this molecule to epileptogenesis is not yet fully understood. Our aim has been to investigate whether PMCA expression in the chronic stages of epilepsy is altered. Through an interdisciplinary approach, involving whole-cell recordings and real-time reverse transcriptase-polymerase chain reaction, we have shown that epileptic neurons in our preparation consistently show changes in electrical properties during the period of chronic epilepsy. These changes included increased spike frequency, altered resting membrane potential and changes in passive membrane properties. Following these observations, which indicate an altered excitability in the epileptic cells studied, PMCA mRNA transcripts were studied. It was found that while PMCA1 transcripts are significantly increased one month following the pilocarpine epileptogenic stimulus, PMCA3, an isoform important in excitable tissues, was significantly, decreased. These findings suggest that, in the long-term, a slow PMCA (PMCA1) plays a role in the reestablishment of a new calcium homeostasis attained by epileptic cells. Overall, this phenomenon points out the fact that in seizure disorders, changes that take place in the balance of the different molecules and their isoforms in charge of maintaining neuronal calcium homeostasis, are fundamental in the survival of affected cells.
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PMID:Analysis of plasma membrane Ca2+-ATPase gene expression during epileptogenesis employing single hippocampal CA1 neurons. 2144 70

The role of microRNAs (miRNAs) in vascular calcification is currently unclear. To examine how miRNAs are involved in vascular smooth muscle cell (VSMC) calcification, we explored the alteration of miRNAs in VSMC calcification in vitro and in vivo. Klotho homozygous mutant mice (kl/kl) display vascular calcification and have perturbations of calcium handling. We therefore hypothesized that the calcium perturbations in VSMCs could be mediated by miRNAs. Using an miRNA array analysis, we demonstrated that miRNAs are aberrantly expressed in the aortic media of 3-week-old kl/kl mice compared with wild-type (WT) mice. The expression levels of miR-135a(*), miR-762, miR-714, and miR-712(*) in the aortic media of kl/kl mice were significantly higher than in WT mice. We used quantitative real-time reverse transcriptase polymerase chain reaction to further confirm that these miRNAs were increased in the aortic media of kl/kl mice and in cultured VSMCs treated with high phosphate and calcium. A search of the miRNA database indicated that the Ca(2+) efflux proteins NCX1, PMCA1, and NCKX4 frequently appeared as potential targets of these miRNAs. The transfection of miRNA mimics into cultured VSMCs reduced the protein levels of each potential target. Conversely, miRNA inhibitors reduced phosphate and calcium-induced VSMC calcification. Furthermore, these inhibitors decreased the intracellular Ca(2+) concentration in cultured VSMCs after treatment with phosphate and calcium. Our results suggest that increased expression of miR-135a(*), miR-762, miR-714, and miR-712(*) in VSMCs may be involved in VSMC calcification by disrupting Ca(2+) efflux proteins.
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PMID:MicroRNAs that target Ca(2+) transporters are involved in vascular smooth muscle cell calcification. 2268 76