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1.
Exp Mol Pathol ; 78(1): 55-7, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15596061

RESUMO

CTLA4 protein is a receptor molecule that plays a critical role as a negative regulator of the immune response. Therefore, genetic variations in CTLA4 may confer susceptibility to autoimmune diseases such as multiple sclerosis (MS). In order to investigate the association of two CTLA4 polymorphisms (+49 A/G and -318 C/T) with multiple sclerosis, sporadic MS patients and healthy controls from Italy were genotyped through direct DNA sequencing. Considering single-loci variations, no differences in the allelic and genotypic frequencies between patients and controls were found. However, considering a putative interaction at the two loci, the T/G combination was more frequently observed in patients than in controls. This result suggests that this allelic combination of the CTLA4 polymorphisms may be involved in the susceptibility to MS in the Italian population.


Assuntos
Antígenos de Diferenciação/genética , Predisposição Genética para Doença , Fragmentos Fc das Imunoglobulinas/genética , Esclerose Múltipla/genética , Polimorfismo Genético , Proteínas Recombinantes de Fusão/genética , Antígenos CD , Antígeno CTLA-4 , Humanos , Itália
2.
Mutat Res ; 554(1-2): 159-63, 2004 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-15450414

RESUMO

SEL1L, a human gene located on chromosome 14q24.3-q31, is highly expressed in adult pancreas. It is proximal to D14S67 (IDDM11) a proposed type I diabetes susceptibility locus. Considering the organ specific expression of SEL1L, a fundamental role of SEL1L in pancreatic growth can be hypothesized. While screening for mutations in young diabetic patients, in children affected by persistent hyperinsulinemic hypoglycemia of infancy (PHHI), in patients with non-functional endocrine tumours and in over 100 control subjects, we identified a novel polymorphism (D162G) residing on the fourth exon of the gene. This exon encodes for the fibronectin type II domain and the nucleotide change involves a highly conserved amino acid. The D162G polymorphism induces a major change in the amino acid composition producing a possible disruptive role in collagen binding.


Assuntos
Hiperinsulinismo Congênito/genética , Fibronectinas/genética , Polimorfismo Genético , Proteínas/genética , Sequência de Aminoácidos , Pré-Escolar , Cromossomos Humanos Par 14 , Humanos , Lactente , Dados de Sequência Molecular , Proteínas/química
4.
J Biol Chem ; 276(49): 46347-63, 2001 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-11562361

RESUMO

We report the cloning of the AOH1 and AOH2 genes, which encode two novel mammalian molybdo-flavoproteins. We have purified the AOH1 protein to homogeneity in its catalytically active form from mouse liver. Twenty tryptic peptides, identified or directly sequenced by mass spectrometry, confirm the primary structure of the polypeptide deduced from the AOH1 gene. The enzyme contains one molecule of FAD, one atom of molybdenum, and four atoms of iron per subunit and shows spectroscopic features similar to those of the prototypic molybdo-flavoprotein xanthine oxidoreductase. The AOH1 and AOH2 genes are 98 and 60 kilobases long, respectively, and consist of 35 coding exons. The AOH1 gene has the potential to transcribe an extra leader non-coding exon, which is located downstream of exon 26, and is transcribed in the opposite orientation relative to all the other exons. AOH1 and AOH2 map to chromosome 1 in close proximity to each other and to the aldehyde oxidase gene, forming a molybdo-flavoenzyme gene cluster. Conservation in the position of exon/intron junctions among the mouse AOH1, AOH2, aldehyde oxidase, and xanthine oxidoreductase loci indicates that these genes are derived from the duplication of an ancestral precursor.


Assuntos
Aldeído Oxirredutases/isolamento & purificação , Mapeamento Cromossômico , Flavoproteínas/genética , Família Multigênica , Aldeído Oxirredutases/química , Aldeído Oxirredutases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromatografia por Troca Iônica , Clonagem Molecular , DNA Complementar , Eletroforese em Gel de Poliacrilamida , Fígado/enzimologia , Camundongos , Dados de Sequência Molecular , Mapeamento de Peptídeos , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
5.
J Biol Chem ; 275(39): 30690-700, 2000 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-10893244

RESUMO

The cDNAs coding for two novel mouse molybdo-flavoproteins, AOH1 and AOH2 (aldehyde oxidase homolog 1 and 2), were isolated. The AOH1 and AOH2 cDNAs code for polypeptides of 1336 amino acids. The two proteins have similar primary structure and show striking amino acid identity with aldehyde oxidase and xanthine oxidoreductase, two other molybdo-flavoenzymes. AOH1 and AOH2 contain consensus sequences for a molybdopterin-binding site and two distinct 2Fe-2S redox centers. In its native conformation, AOH1 has a molecular weight consistent with a homotetrameric structure. Transfection of the AOH1 and AOH2 cDNAs results in the production of proteins with phenanthridine but not hypoxanthine oxidizing activity. Furthermore, the AOH1 protein has benzaldehyde oxidizing activity with electrophoretic characteristics identical to those of a previously identified aldehyde oxidase isoenzyme (Holmes, R. S. (1979) Biochem. Genet. 17, 517-528). The AOH1 transcript is expressed in the hepatocytes of the adult and fetal liver and in spermatogonia. In liver, the AOH1 protein is synthesized in a gender-specific fashion. The expression of AOH2 is limited to keratinized epithelia and the basal layer of the epidermis and hair folliculi. The selective cell and tissue distribution of AOH1 and AOH2 mRNAs is consistent with the localization of the respective protein products.


Assuntos
Coenzimas , Molibdênio , Oxirredutases/genética , Aldeído Oxidase , Aldeído Oxirredutases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Sequência Consenso , DNA Complementar , Desulfovibrio/enzimologia , Evolução Molecular , Feminino , Humanos , Masculino , Metaloproteínas/metabolismo , Camundongos , Proteínas Mitocondriais , Dados de Sequência Molecular , Cofatores de Molibdênio , Oxirredutases/metabolismo , Filogenia , Proteínas de Plantas/genética , Pteridinas/metabolismo , Proteínas Recombinantes/biossíntese , Homologia de Sequência de Aminoácidos , Caracteres Sexuais , Distribuição Tecidual , Xantina Oxidase/genética
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