PT  - JOURNAL ARTICLE
AU  - Agata Stepien
AU  - Jakub Dolata
AU  - Tomasz Gulanicz
AU  - Dawid Bielewicz
AU  - Mateusz Bajczyk
AU  - Dariusz J. Smolinski
AU  - Zofia Szweykowska-Kulinska
AU  - Artur Jarmolowski
TI  - Chromatin-associated microprocessor assembly is regulated by PRP40, the U1 snRNP auxiliary protein
AID  - 10.1101/2022.01.31.478465
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.01.31.478465
4099  - http://biorxiv.org/content/early/2022/01/31/2022.01.31.478465.short
4100  - http://biorxiv.org/content/early/2022/01/31/2022.01.31.478465.full
AB  - Cotranscriptional processing of RNA polymerase II-generated primary transcripts is a well-documented phenomenon. We recently showed that in plants, miRNA biogenesis is also a cotranscriptional event. Here, we report that Arabidopsis PRP40, the U1 snRNP auxiliary protein, positively regulates the recruitment of SE, the core component of the plant microprocessor, to miRNA genes. The association of DCL1, the microprocessor endoribonuclease, with chromatin was altered in prp40ab mutant plants. Impaired cotranscriptional microprocessor assembly was accompanied by RNA polymerase II accumulation at miRNA genes and retention of miRNA precursors at their transcription sites in the prp40ab mutant plants. We show that cotranscriptional microprocessor assembly, regulated by AtPRP40, positively affects RNAPII transcription of miRNA genes and is important to reach the correct levels of produced miRNAs.Competing Interest StatementThe authors have declared no competing interest.