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1.
Sci Adv ; 7(2)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33523995

RESUMO

Human adenovirus (HAdV) types F40 and F41 are a prominent cause of diarrhea and diarrhea-associated mortality in young children worldwide. These enteric HAdVs differ notably in tissue tropism and pathogenicity from respiratory and ocular adenoviruses, but the structural basis for this divergence has been unknown. Here, we present the first structure of an enteric HAdV-HAdV-F41-determined by cryo-electron microscopy to a resolution of 3.8 Å. The structure reveals extensive alterations to the virion exterior as compared to nonenteric HAdVs, including a unique arrangement of capsid protein IX. The structure also provides new insights into conserved aspects of HAdV architecture such as a proposed location of core protein V, which links the viral DNA to the capsid, and assembly-induced conformational changes in the penton base protein. Our findings provide the structural basis for adaptation of enteric HAdVs to a fundamentally different tissue tropism.

2.
J Evol Biol ; 22(5): 1098-1110, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-21462414

RESUMO

Recent studies on parallel evolution have focused on the relative role of selection and historical contingency during adaptive divergence. Here, we study geographically separate and genetically independent lake populations of a freshwater isopod (Asellus aquaticus) in southern Sweden. In two of these lakes, a novel habitat was rapidly colonized by isopods from a source habitat. Rapid phenotypic changes in pigmentation, size and sexual behaviour have occurred, presumably in response to different predatory regimes. We partitioned the phenotypic variation arising from habitat ('selection': 81­94%), lake ('history': 0.1­6%) and lake × habitat interaction ('unique diversification': 0.4­13%) for several traits. There was a limited role for historical contingency but a strong signature of selection. We also found higher phenotypic variation in the source populations. Phenotype sorting during colonization and strong divergent selection might have contributed to these rapid changes. Consequently, phenotypic divergence was only weakly influenced by historical contingency.


Assuntos
Evolução Biológica , Tamanho Corporal/fisiologia , Ecossistema , Isópodes/fisiologia , Fenótipo , Pigmentação/fisiologia , Comportamento Sexual Animal/fisiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Análise de Variância , Animais , Sequência de Bases , Análise por Conglomerados , DNA Mitocondrial/genética , Análise Discriminante , Água Doce , Haplótipos , Modelos Lineares , Dados de Sequência Molecular , Seleção Genética , Análise de Sequência de DNA , Suécia
3.
J Virol ; 74(16): 7691-3, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10906228

RESUMO

Selected members of the adenovirus family have been shown to interact with the coxsackie adenovirus receptor, alpha(v) integrins, and sialic acid on target cells. Initial interactions of subgenus D adenoviruses with target cells have until now been poorly characterized. Here, we demonstrate that adenovirus type 8 (Ad8), Ad19a, and Ad37 use sialic acid as a functional cellular receptor, whereas the Ad9 and Ad19 prototypes do not.


Assuntos
Adenovírus Humanos/metabolismo , Antígenos CD/metabolismo , Proteínas do Capsídeo , Ácido N-Acetilneuramínico/metabolismo , Receptores Virais/metabolismo , Adenovírus Humanos/classificação , Adenovírus Humanos/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Capsídeo/química , Capsídeo/genética , Enterovirus Humano B/metabolismo , Humanos , Integrina alfaV , Dados de Sequência Molecular , Células Tumorais Cultivadas
4.
J Virol ; 74(1): 42-8, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10590089

RESUMO

Two cellular receptors for adenovirus, coxsackievirus-adenovirus receptor (CAR) and major histocompatibility complex class I (MHC-I) alpha2, have recently been identified. In the absence of CAR, MHC-I alpha2 has been suggested to serve as a cellular attachment protein for subgenus C adenoviruses, while members from all subgenera except subgenus B have been shown to interact with CAR. We have found that adenovirus type 37 (Ad37) attachment to CAR-expressing CHO cells was no better than that to CHO cells lacking CAR expression, suggesting that CAR is not used by Ad37 during attachment. Instead, we have identified sialic acid as a third adenovirus receptor moiety. First, Ad37 attachment to both CAR-expressing CHO cells and MHC-I alpha2-expressing Daudi cells was sensitive to neuraminidase treatment, which eliminates sialic acid on the cell surface. Second, Ad37 attachment to sialic acid-expressing Pro-5 cells was more than 10-fold stronger than that to the Pro-5 subline Lec2, which is deficient in sialic acid expression. Third, neuraminidase treatment of A549 cells caused a 60% decrease in Ad37 replication in a fluorescent-focus assay. Moreover, the receptor sialoconjugate is most probably a glycoprotein rather than a ganglioside, since Ad37 attachment to sialic acid-expressing Pro-5 cells was sensitive to protease treatment. Ad37 attachment to Pro-5 cells occurs via alpha(2-->3)-linked sialic acid saccharides rather than alpha(2-->6)-linked ones, since (i) alpha(2-->3)-specific but not alpha(2-->6)-specific lectins blocked Ad37 attachment to Pro-5 cells and (ii) pretreatment of Pro-5 cells with alpha(2-->3)-specific neuraminidase resulted in decreased Ad37 binding. Taken together, these results suggest that, unlike Ad5, Ad37 makes use of alpha(2-->3)-linked sialic acid saccharides on glycoproteins for entry instead of using CAR or MHC-I alpha2.


Assuntos
Adenoviridae/fisiologia , Glicoproteínas de Membrana/fisiologia , Ácido N-Acetilneuramínico/fisiologia , Receptores Virais/fisiologia , Adenoviridae/patogenicidade , Animais , Células CHO , Linhagem Celular , Cricetinae , Humanos , Fusão de Membrana/efeitos dos fármacos , Neuraminidase/farmacologia , Virulência/efeitos dos fármacos
5.
Virology ; 227(1): 239-44, 1997 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-9007080

RESUMO

We have characterized the fibergenes of adenovirus type 19p (Ad19p), Ad19a, and Ad37 by sequencing. The fiber genes of Ad19a and Ad37 are identical and only five amino acids differ comparing Ad19a/Ad37 with Ad19p. Based on the translated sequences we calculated the isoelectrical points (Ips) and found that the fiber knobs of Ad19p, Ad19a, and Ad37 together with Ad8 display the highest Ips of all so far characterized. Two regions within the fiber knob with unusually basic characteristics have been identified. Sequence alignments revealed that the corresponding regions in other fiber knobs are highly antigenic in pepscan analysis and of importance for hemagglutination. Only two positions differ in the knobs comparing Ad19a/Ad37 with Ad19p. Hence, either of these or both amino acid residues should be expected to be responsible for the observed differences in hemagglutination between Ad19p and Ad19a/Ad37. Moreover, we have found two amino acids (Ala227 and Lys252) that are unique in their respective position in Ad19p, Ad19a, Ad37, and Ad8. Three amino acids (Lys236, Lys240, and Asn251) are unique in their respective position in Ad19a and Ad37, that manifest a tropism for the genital tract. All five amino acids colocalize within one of the two basic regions.


Assuntos
Adenovírus Humanos/genética , Proteínas do Capsídeo , Capsídeo/genética , Olho/virologia , Genitália/virologia , Adenovírus Humanos/crescimento & desenvolvimento , Sequência de Aminoácidos , Capsídeo/química , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência de Aminoácidos
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