Intrinsically disordered proteins SAID1/2 condensate on SERRATE for dual inhibition of miRNA biogenesis in Arabidopsis.
Proc Natl Acad Sci U S A
; 120(14): e2216006120, 2023 04 04.
Article
em En
| MEDLINE
| ID: mdl-36972460
ABSTRACT
Intrinsically disordered proteins (IDPs) SAID1/2 are hypothetic dentin sialophosphoprotein-like proteins, but their true functions are unknown. Here, we identified SAID1/2 as negative regulators of SERRATE (SE), a core factor in miRNA biogenesis complex (microprocessor). Loss-of-function double mutants of said1; said2 caused pleiotropic developmental defects and thousands of differentially expressed genes that partially overlapped with those in se. said1; said2 also displayed increased assembly of microprocessor and elevated accumulation of microRNAs (miRNAs). Mechanistically, SAID1/2 promote pre-mRNA processing 4 kinase A-mediated phosphorylation of SE, causing its degradation in vivo. Unexpectedly, SAID1/2 have strong binding affinity to hairpin-structured pri-miRNAs and can sequester them from SE. Moreover, SAID1/2 directly inhibit pri-miRNA processing by microprocessor in vitro. Whereas SAID1/2 did not impact SE subcellular compartmentation, the proteins themselves exhibited liquid-liquid phase condensation that is nucleated on SE. Thus, we propose that SAID1/2 reduce miRNA production through hijacking pri-miRNAs to prevent microprocessor activity while promoting SE phosphorylation and its destabilization in Arabidopsis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arabidopsis
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Proteínas de Arabidopsis
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MicroRNAs
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Proteínas Intrinsicamente Desordenadas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article