Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mol Biol Cell ; 22(1): 153-64, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21119001

RESUMO

Cand1 inhibits cullin RING ubiquitin ligases by binding unneddylated cullins. The Cand1 N-terminus blocks the cullin neddylation site, whereas the C-terminus inhibits cullin adaptor interaction. These Cand1 binding sites can be separated into two functional polypeptides which bind sequentially. C-terminal Cand1 can directly bind to unneddylated cullins in the nucleus without blocking the neddylation site. The smaller N-terminal Cand1 cannot bind to the cullin neddylation region without C-terminal Cand1. The separation of a single cand1 into two independent genes represents the in vivo situation of the fungus Aspergillus nidulans, where C-terminal Cand1 recruits smaller N-terminal Cand1 in the cytoplasm. Either deletion results in an identical developmental and secondary metabolism phenotype in fungi, which resembles csn mutants deficient in the COP9 signalosome (CSN) deneddylase. We propose a two-step Cand1 binding to unneddylated cullins which initiates at the adaptor binding site and subsequently blocks the neddylation site after CSN has left.


Assuntos
Aspergillus nidulans/metabolismo , Proteínas Culina/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fusão Gênica Artificial , Aspergillus nidulans/genética , Aspergillus nidulans/crescimento & desenvolvimento , Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/metabolismo , Proteínas Culina/química , Proteínas Culina/genética , Citoplasma/metabolismo , Proteínas Fúngicas/química , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Ligação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Fatores de Transcrição/química , Técnicas do Sistema de Duplo-Híbrido , Ubiquitinação , Ubiquitinas/metabolismo
2.
Proc Natl Acad Sci U S A ; 104(19): 8089-94, 2007 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-17470786

RESUMO

Fruit body formation in filamentous fungi is a complex and yet hardly understood process. We show here that protein turnover control is crucial for Aspergillus nidulans development. Deletion of genes encoding COP9 signalosome (CSN) subunits 1, 2, 4, or 5 resulted in identical blocks in fruit body formation. The CSN multiprotein complex controls ubiquitin-dependent protein degradation in eukaryotes. Six CSN subunits interacted in a yeast two-hybrid analysis, and the complete eight-subunit CSN was recruited by a functional tandem affinity purification tag fusion of subunit 5 (CsnE). The tagged CsnE was unable to recruit any CSN subunit in a strain deleted for subunit 1 or subunit 4. Mutations in the JAMM metalloprotease core of CsnE resulted in mutant phenotypes identical to those of csn deletion strains. We propose that a correctly assembled CSN including a functional JAMM links protein turnover to fungal sexual development.


Assuntos
Aspergillus nidulans/crescimento & desenvolvimento , Complexos Multiproteicos/química , Peptídeo Hidrolases/química , Motivos de Aminoácidos , Aspergillus nidulans/genética , Complexo do Signalossomo COP9 , Genoma Fúngico , Complexos Multiproteicos/fisiologia , Peptídeo Hidrolases/fisiologia , Fenótipo , Subunidades Proteicas
3.
Curr Biol ; 15(13): 1242-8, 2005 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-16005299

RESUMO

Aspergillus fumigatus is a medically important opportunistic pathogen and a major cause of respiratory allergy. The species has long been considered an asexual organism. However, genome analysis has revealed the presence of genes associated with sexual reproduction, including a MAT-2 high-mobility group mating-type gene and genes for pheromone production and detection (Galagan et al., personal communication; Nierman et al., personal communication). We now demonstrate that A. fumigatus has other key characteristics of a sexual species. We reveal the existence of isolates containing a complementary MAT-1 alpha box mating-type gene and show that the MAT locus has an idiomorph structure characteristic of heterothallic (obligate sexual outbreeding) fungi. Analysis of 290 worldwide clinical and environmental isolates with a multiplex-PCR assay revealed the presence of MAT1-1 and MAT1-2 genotypes in similar proportions (43% and 57%, respectively). Further population genetic analyses provided evidence of recombination across a global sampling and within North American and European subpopulations. We also show that mating-type, pheromone-precursor, and pheromone-receptor genes are expressed during mycelial growth. These results indicate that A. fumigatus has a recent evolutionary history of sexual recombination and might have the potential for sexual reproduction. The possible presence of a sexual cycle is highly significant for the population biology and disease management of the species.


Assuntos
Aspergillus fumigatus/genética , Aspergillus fumigatus/fisiologia , Genes Fúngicos/genética , Genes Fúngicos Tipo Acasalamento , Genoma Fúngico , Sexo , Sequência de Aminoácidos , Sequência de Bases , Primers do DNA , Componentes do Gene , Genética Populacional , Genômica/métodos , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Polimorfismo de Fragmento de Restrição , Reprodução/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...