The role of HYL1 in MIR genes transcription

HYL1 (DRB1) is a double-stranded RNA-binding protein involved in miRNA processing in plants. It is a core component of the Microprocessor complex and enhances the efficiency and precision of miRNA processing by the DCL1 protein. In this work, we report a novel function of HYL1 protein in the transcription of MIR genes. DRB1 co-localizes with RNA Polymerase II and affects its distribution along MIR genes. Moreover, proteomic experiments revealed that HYL1 protein interacts with many transcription factors. Finally, we show that the action of DRB1 is not limited to MIR genes as it impacts the expression of many other genes, the majority of which are involved in plant response to light. These discoveries add DRB1 as another player in gene regulation at the transcriptional level, independent of its role in miRNA biogenesis. RNA Polymerase II distribution in hyl1-2 Grant ID: 2022/45/B/NZ1/01273 Grant title: Consequences of posttranslational modifications of HYL1 for plant development Funding source: National Science Center Poland