Hyponastic Leaves 1 Interacts with RNA Pol II to Ensure Proper Transcription of MicroRNA Genes

Hyponastic Leaves 1 (HYL1) [also known as Double-stranded RNA-Binding protein 1 (DRB1)] is a double-stranded RNA-binding protein involved in microRNA (miRNA) processing in plants. It is a core component of the Microprocessor complex and enhances the efficiency and precision of miRNA processing by the Dicer-Like 1 protein. In this work, we report a novel function of the HYL1 protein in the transcription of miRNA (MIR) genes. HYL1 colocalizes with RNA polymerase II and affects its distribution along MIR genes. Moreover, proteomic experiments revealed that the HYL1 protein interacts with many transcription factors. Finally, we show that the action of HYL1 is not limited to MIR genes and impacts the expression of many other genes, a majority of which are involved in plastid organization. These discoveries indicate HYL1 as an additional player in gene regulation at the transcriptional level, independent of its role in miRNA biogenesis.

Automated summary

HYL1, also known as DRB1, is a double-stranded RNA-binding protein involved in miRNA processing in plants. It was found to have a novel function in the transcription of MIR genes, affecting the distribution of RNA polymerase II and interacting with various transcription factors. Additionally, HYL1 was found to impact the expression of many other genes, particularly those involved in plastid organization.