Identification and expression of a new splicing variant of FAD-sulfhydryl oxidase in adult rat brain.
Flavoproteins of the quiescin/sulfhydryl oxidase (QSOX) family catalyze oxidation of peptide and protein thiols to disulfides with the reduction of oxygen to hydrogen peroxide. We report here the molecular cloning of a new putative sulfhydryl oxidase cDNA, rQSOX-L (GenBank Accession no ), from adult rat brain and its expression studied by RT-PCR, Northern and Western blots in rat tissues. DNA-sequencing demonstrated the existence of two cDNAs in rat cortex, corresponding to a long transcript (rQSOX-L) and a short transcript (rQSOX-S) which differed by 851 nucleotides due to alternative splicing. The new transcript, rQSOX-L (3356 nucleotides), was specifically expressed in brain, hypophysis, heart, testis and seminal vesicle. The distribution of this variant is not homogeneous in the different tissues studied and suggests a complex gene regulation. The full-length rQSOX-L cDNA has an open reading frame of 2250-bp encoding a protein of 750 amino acids that contains a signal peptide sequence, a protein-disulfide-isomerase-type thioredoxin and ERV1-ALR domains and a long form specific C-terminal extension. The rQSOX-L protein is highly homologous to members of the sulfhydryl oxidase/Quiescin family and contains particularly two potential sites for N-glycosylation. This protein isoform was specifically detected in rat brain tissues in opposition to the low molecular form that was ubiquitous. Matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis of the immunoprecipitate tryptic fragments allowed the identification of rQSOX-L protein.
Radom
Jean
J
Equipe "Estrogènes, Expression Génique et Pathologie du Système Nerveux Central", E. A. 3922, IFR 133, Université de Franche-Comté, UFR Sciences et Techniques, 16 Route de Gray, 25030 Besançon cedex, France.
Colin
Didier
D
Thiebault
Franck
F
Dognin-Bergeret
Mai
M
Mairet-Coello
Georges
G
Esnard-Feve
Annick
A
Fellmann
Dominique
D
Jouvenot
Michèle
M
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology; D002540:Cerebral Cortex / Q000201:enzymology*; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D015870:Gene Expression; D016678:Genome; D006031:Glycosylation; D047468:Immunoprecipitation; D008297:Male; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic; D050862:Oxidoreductases Acting on Sulfur Group Donors
D005182:Flavin-Adenine Dinucleotide; D010088:Oxidoreductases; D012333:RNA, Messenger; D050862:Oxidoreductases Acting on Sulfur Group Donors