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

The cardiac (versus retinal rod) Na/Ca exchanger gene has been cloned, sequenced and shown by RNA analysis to be present in diverse tissues. Analysis of published sequences shows that a single isoform is found in heart tissue from many species (NACA1 isoform). We provide evidence here by ribonuclease (RNase) protection assays and by reverse transcriptase-polymerase chain reaction (PCR) amplification with sequence analysis that a new isoform encoding the Na/Ca exchanger is present in renal tissue. This isoform (NACA3) reveals a 7-amino acid deletion in the tested region compared with the NACA2 isoform described by Reilly and Shugrue [Am. J. Physiol. 262 (Renal Fluid Electrolyte Physiol. 31): F1105-F1109, 1992] and is the dominant exchanger transcript in kidney. Analysis of the sequence of all isoforms indicates that the differences in the isoforms reside in the large intracellular loop region of the protein. Alternative splicing of a single Na/Ca exchanger message may be responsible for these tissue-specific transcripts.
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PMID:Na/Ca exchanger isoforms expressed in kidney. 769 82

The Na+/Ca2+ exchanger is an important plasma-membrane Ca2+ transport protein. Functional studies of the effects of removal of external Na+ on airway smooth muscle tone, and studies of Na+-dependent Ca2+ fluxes in membrane vesicles have provided indirect evidence of an important role for Na+/Ca2+ exchange in regulating airway smooth muscle tone. Recent molecular studies have identified seven isoforms of the Na+/Ca2+ exchanger (NCX1) gene in other tissues, but direct molecular characterization of the airway smooth muscle Na+/Ca2+ exchanger has not previously been performed. We have therefore used a reverse transcriptase-polymerase chain (RT-PCR) reaction method and DNA sequencing to study the Na+/Ca2+ exchanger isoform present in human airway smooth muscle. The dominant isoform was found to be virtually identical to the NACA3 isoform originally described in rabbit kidney cortex. The DNA sequence of the Na+/Ca2+ exchanger exon B that we obtained is previously unpublished for any human tissue. This study provides the first definitive molecular evidence of the existence of an Na+/Ca2+ exchanger in airway smooth muscle. The molecular characterization of the human airway smooth muscle Na+/Ca2+ exchanger will facilitate future electrophysiologic studies of its function.
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PMID:Molecular characterization of the human airway smooth muscle Na+/Ca2+ exchanger. 896 66

The Na+-Ca2+ exchanger (NCX) is well known to regulate intracellular Ca2+ concentration in many excitable cells. To date, three members of the NCX exchanger gene family have been identified: NCX1, NCX2 and NCX3. In zona fasciculata of the bovine adrenal gland, a Na+-Ca2+ exchanger has been recently found to display biochemical similarities with the NCX1 exchanger of renal basolateral cells. Although a Na+-Ca2+ exchanger has already been characterized in zona medulla of adrenal gland, such an exchanger has never been studied in the adrenal cortex. Thus, we have used a reverse transcriptase-polymerase chain reaction (RT-PCR) assay with specific NCX primers on fasciculata cell cultures. The sequencing of the amplified fragment revealed, for the first time, the presence of a NACA3 isoform of the NCX1 exchanger in the adrenal cortex, similar to the one found in adrenal chromaffin cells and in renal cortex. This isoform is 92 and 94% identical in the portion compared with kidney Na+-Ca2+ exchanger NACA3 of rat and pig, respectively.
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PMID:Characterization of a Na+-Ca2+ exchanger NCX1 isoform in bovine fasciculata cells of adrenal gland. 1133 Aug 36