Homodimerization of HYL1 ensures the correct selection of cleavage sites in primary miRNA.
Bottom Line: Disruption of HYL1 homodimerization causes incorrect cleavage at sites in pri-miRNA without interrupting the interaction of HYL1 with DCL1 and accumulation of pri-miRNAs in HYL1/pri-miRNA complexes, leading to a reduction in the efficiency and accuracy of miRNAs that results in strong mutant phenotypes of the plants.HYL1 homodimers may function as a molecular anchor for DCL1 to cleave at a distance from the ssRNA-dsRNA junction in pri-miRNA.These results suggest that HYL1 ensures the correct selection of pri-miRNA cleavage sites through homodimerization and thus contributes to gene silencing and plant development.
Affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.Show MeSH
Mentions: HYL1 is known to interact with DCL1 and SE, but whether non-dimerized HYL1 interacts with DCL1 and SE remains unknown. Therefore, we used BiFC analysis to determine the effects of the point mutations on their interactions with DCL1 and SE. In Arabidopsis protoplasts, all transiently expressed HYL1 mutants, including G147E and L165E, were found to interact with DCL1 and SE, implying that a deficiency in HYL1 dimerization did not affect protein–protein interactions of HYL1 with DCL1 and SE (Figure 3A; Supplementary Figure S3B).
Affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.