Characteristics of NADPH oxidase genes (Nox2, p22, p47, and p67) and Nox4 gene expressed in blood cells of juvenile Ciona intestinalis.
To illuminate the origins of NADPH oxidase (Nox), we identified cDNA clones encoding Nox2, Nox4, p22 phagocyte oxidase (phox), p47phox, and p67phox in a chordate phylogenetically distant to the vertebrates, the sea squirt Ciona intestinalis. We also examined the spatiotemporal expression of these genes in embryos and juveniles. The sequences of the Nox2, Nox4, p22phox, p47phox, and p67phox cDNAs contained open reading frames encoding 581, 811, 175, 461, and 515 amino acids, respectively. The level of identities between the deduced Nox2, Nox4, p22phox, p47phox, and p67phox amino acid sequences and their corresponding human components were 54.0, 31.0, 44.4, 36.0, and 26.2%, respectively. Despite these low identities, the functional domains of the C. intestinalis and human NADPH oxidase and Nox4 are highly conserved. The genomic organizations of the components of the NADPH oxidase gene except for p67phox (a single exon gene) and the Nox4 gene in C. intestinalis are highly similar to those of the corresponding human NADPH oxidase genes. Further, the analyzed part of the C. intestinalis genome and EST database do not seem to present p40phox and Nox5. The Nox2, p22phox, p47phox, and p67phox genes were specifically expressed in the blood cells of juveniles. The Nox4 gene was expressed in blood cells and endostyle of juveniles. These results suggest that C. intestinalis NADPH oxidase components possess potential functional activities similar to those of human, but the manner in which cytosolic phox proteins in C. intestinalis interact is different from that in human.
Inoue
Yuuki
Y
Laboratory of Fish Pathology, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Kameino 1866, Fujisawa, Kanagawa, 252-8510, Japan, yinoue3@emory.edu
Ogasawara
Michio
M
Moroi
Takuma
T
Satake
Masanobu
M
Azumi
Kaoru
K
Moritomo
Tadaaki
T
Nakanishi
Teruyuki
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002938:Ciona intestinalis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D018076:DNA, Complementary / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D016678:Genome; D006801:Humans; D017403:In Situ Hybridization; D008954:Models, Biological; D008969:Molecular Sequence Data; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000097:blood / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D018076:DNA, Complementary; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human