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Titolo:
A glycosyl hydrolase activity of mammalian reovirus sigma 1 protein can contribute to viral infection through a mucus layer
Autore:
Bisaillon, M; Senechal, S; Bernier, L; Lemay, G;
Indirizzi:
Univ Montreal, Dept Microbiol & Immunol, Montreal, PQ H3C 3J7, Canada UnivMontreal Montreal PQ Canada H3C 3J7 ol, Montreal, PQ H3C 3J7, Canada
Titolo Testata:
JOURNAL OF MOLECULAR BIOLOGY
fascicolo: 3, volume: 286, anno: 1999,
pagine: 759 - 773
SICI:
0022-2836(19990226)286:3<759:AGHAOM>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
SITE-DIRECTED MUTAGENESIS; EGG-WHITE LYSOZYME; INTESTINAL MUCIN; CANDIDA-ALBICANS; GENE; RESIDUES; PURIFICATION; ALIGNMENT; PARTICLES; BREAKDOWN;
Keywords:
reovirus; glycosidase; mucin;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
44
Recensione:
Indirizzi per estratti:
Indirizzo: Lemay, G UnivQMontreal, Dept Microbiol & Immunol, POB 6128,Stn Ctrville, Montreal, P Univ Montreal POB 6128,Stn Ctrville Montreal PQ Canada H3C 3J7 P
Citazione:
M. Bisaillon et al., "A glycosyl hydrolase activity of mammalian reovirus sigma 1 protein can contribute to viral infection through a mucus layer", J MOL BIOL, 286(3), 1999, pp. 759-773

Abstract

The mammalian reovirus ol protein is responsible for viral attachment to host cells and hemagglutination properties of the virus. In the present study, sequence similarity between al and chicken-type lysozymes prompted us toinvestigate additional functions of the ol protein. Expression in Pichia pastoris yeast cells showed that al can actually cleave lysozyme substrates,including complex sugars found in bacterial cell walls. Replacement by site-directed mutagenesis of acidic amino acid residues in ol by their respective isosteric, uncharged, amino acid residues has allowed us to identify Glu36 and Asp54 as the catalytic pair involved in ol-mediated glycosidase activity. The enzyme appears inactive in virions but its activity is unmasked upon generation of infectious subviral particles (ISVPs) by partial proteolytic removal of the outer capsid proteins. Purified ol protein and ISVPs can also hydrolyze mucins, heavily glycosylated glycoproteins that are a major component of the mucus layer overlaying the intestinal epithelium. Furthermore, reovirus infection of epithelial Madin Darby canine kidney cells wasinhibited tenfold in cells expressing mucin at their apical surface, whilethis inhibition was overcome by ISVPs. Unmasking of al mucinolytic activity in the intestine, consecutive to proteolytic cleavage of virions to ISVPs, thus likely contributes to the known increase in infectivity of reovirus ISVPs compared to complete virions. This work presents the first evidence that some mammalian viruses have evolved mechanisms to facilitate their penetration through the protective barrier of the mucus layer in the intestinaltract. (C) 1999 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 18:29:15