Genetic screen for suppression of transcriptional interference identifies a gain-of-function mutation in Pol2 termination factor Seb1.
Proc Natl Acad Sci U S A
; 118(33)2021 08 17.
Article
em En
| MEDLINE
| ID: mdl-34389684
ABSTRACT
The system of long noncoding RNA (lncRNA)-mediated transcriptional interference that represses fission yeast phosphate homoeostasis gene pho1 provides a sensitive readout of genetic influences on cotranscriptional 3'-processing and termination and a tool for discovery of regulators of this phase of the Pol2 transcription cycle. Here, we conducted a genetic screen for relief of transcriptional interference that unveiled a mechanism by which Pol2 termination is enhanced via a gain-of-function mutation, G476S, in the RNA-binding domain of an essential termination factor, Seb1. The genetic and physical evidence for gain-of-function is compelling 1) seb1-G476S de-represses pho1 and tgp1, both of which are subject to lncRNA-mediated transcriptional interference; 2) seb1-G476S elicits precocious lncRNA transcription termination in response to lncRNA 5'-proximal poly(A) signals; 3) seb1-G476S derepression of pho1 is effaced by loss-of-function mutations in cleavage and polyadenylation factor (CPF) subunits and termination factor Rhn1; 4) synthetic lethality of seb1-G476S with pho1 derepressive mutants rpb1-CTD-S7A and aps1∆ is rescued by CPF/Rhn1 loss-of-function alleles; and 5) seb1-G476S elicits an upstream shift in poly(A) site preference in several messenger RNA genes. A crystal structure of the Seb1-G476S RNA-binding domain indicates potential for gain of contacts from Ser476 to RNA nucleobases. To our knowledge, this is a unique instance of a gain-of-function phenotype in a eukaryal transcription termination protein.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Schizosaccharomyces
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Proteínas Fúngicas
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Regulação Fúngica da Expressão Gênica
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Mutação com Ganho de Função
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2021
Tipo de documento:
Article