The 30th International Conference on Arabidopsis Research (ICAR 2019)

547 / 2019-03-15 06:03:10

MAC5, an RNA-binding protein, protects pri-miRNAs from SERRATE-dependent exoribonuclease activities

MAC5A, RNA-binding, microRNAs,

Plenary track > RNA Biology

CDC5, PRL1, MAC7, and MAC3 are subject to MOS4-associated complex (MAC) (also termed as NTC), which contains five core components and several associated proteins, including the RNA binding protein MAC5. Arabidopsis MAC5 was previously reported to play a role in seedling development and snc1-mediated autoimmunity. Here, we report a novel function of MAC5 in miRNA biogenesis. MAC5 is an RNA-binding protein, which can directly bind the stem-loop region of pri-miRNAs. In addition, MAC5 interacts with DCL1 components and accelerates pri-miRNA processing. Most importantly, our data show that MAC5 protects pri-miRNA transcripts from degradation of SE-dependent exoribonuclease. Based on these results, we propose that MAC5 controls miRNA levels through modulating pri-miRNA processing and stability.