Cooperative interaction of branch signals in the actin intron of Saccharomyces cerevisiae.
Nucleic Acids Res
; 26(18): 4137-45, 1998 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-9722632
ABSTRACT
In pre-mRNA splicing, specific spliceosomal components recognize key intron sequences, but the mechanisms by which splice sites are selected arenot completely understood. In the Saccharomyces cerevisiae actin intron a silent branch point-like sequence (UACUAAG) is located 7 nt upstream of the canonical sequence. Mutation of the canonicalUACUAAC sequence to UAAUAAC reduces utilization of this signal and activates the cryptic UACUAAG. Splicing-dependent beta-galactosidase assays have shown that these two splice signals cooperate to enhance splicing. Analyses of several variants of this double branch point intron demonstrate that the upstream UACUAAG sequence significantly increases usage of the UAAUAAC as a site of lariat formation. This activation is sequence-specific and unidirectional. However the ability of the UACUAAG signal to activate the downstream branch point is dependent on the presence of a short non-conserved sequence located a few nucleotides upstream of the UACUAAG. Mutation of this sequence leads to the disappearance of the cooperative interactions between the two branch signals. Our results show that this non-conserved sequence and the UACUAAG signal must both be present to achieve activation of the downstream branch point and suggest that a specific structure may be necessary to allow efficient recognition of the UAAUAAC.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Precursores de RNA
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Íntrons
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Splicing de RNA
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Actinas
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
ENGLAND
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ESCOCIA
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GB
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GREAT BRITAIN
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INGLATERRA
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REINO UNIDO
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SCOTLAND
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UK
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UNITED KINGDOM