Human and rat testis express two mRNA species encoding variants of NRD convertase, a metalloendopeptidase of the insulinase family.
Rat testis NRD convertase (EC 3.4.24.61) is a Zn2+-dependent endopeptidase that cleaves, in vitro, peptide substrates at the N-terminus of Arg residues in dibasic sites. This putative processing enzyme of the insulinase family of metallopeptidases exhibits a significant degree of similarity to insulinase and two yeast processing enzymes, Axl1 and Ste23. We report the cloning of two human testis cDNA species encoding isoforms of NRD convertase, hNRD1 and hNRD2. Whereas the hNRD1 transcript (3.7 kb) is equivalent to the previously characterized rat cDNA (rNRD1), hNRD2 and rNRD2 are 3.9 kb novel forms containing a nucleotide insertion encoding a 68-residue segment. This motif, which is inserted N-terminal of the Zn2+-binding site, HXXEH, is contained within the most conserved region among the insulinase family members. Analysis of the deduced primary sequences revealed 92% identity between rat and human orthologues. The human gene encoding NRD convertase was localized to chromosome 1p32.1-p32.2. Whereas NRD convertase is mostly expressed in testis and in 24 cell lines, low mRNA levels were detected in most of the 27 other tissues tested.
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Laboratoire de Biochimie des Signaux Régulateurs Cellulaires et Moléculaires, Unité de Recherche Associée au Centre National de la Recherche Scientifique 1682, Université Pierre et Marie Curie, 96 Bd Raspail, 75006 Paris, France.
Prat
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Joulie
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Chérif
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Day
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Cohen
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007339:Insulysin / Q000096:biosynthesis / Q000235:genetics*; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D008666:Metalloendopeptidases / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013552:Swine; D013737:Testis / Q000201:enzymology* / Q000378:metabolism
D018076:DNA, Complementary; D007527:Isoenzymes; D012333:RNA, Messenger; D008666:Metalloendopeptidases; D007339:Insulysin; C087976:nardilysin