637 / 2019-04-28 12:48:57

RNA binding protein regulates plant flowering by targeting alternative polyadenylation in Arabidopsis.

RNA binding protein flowering alternative polyadenylation

全体主题 > RNA Biology

Alternative polyadenylation (APA) is a widespread mechanism for gene regulation and has been implicated in flowering, but the molecular basis governing the choice of a specific poly(A) site during the vegetative-to-reproductive growth transition remains unclear. Here we characterize HLP1 and HLP2 as novel regulators for APA in Arabidopsis. Phenotype analysis shows HLP1 and HLP2 regulate flowering time in a FLC-dependent way, and hlp1hlp2 double mutant are embryo lethal, implying the significance of HLP1 and HLP2 in plant development. Genome-wide mapping of HLP1-RNA interactions indicates that HLP1 binds preferentially to A-rich and U-rich elements around cleavage and polyadenylation sites, implicating its role in APA. Comprehensive profiling of the poly(A) site usage reveals that HLP1 and HLP2 mutations cause thousands of poly(A) site shifts. And the mutation of HLP2 leads to similar APA shift with that of hlp1 mutant, particularly, a distal-to-proximal poly(A) site shift in FCA, a direct target of HLP1 and HLP2, leads to upregulation of FLC and delayed flowering. Interestingly, HLP1 negatively modulates HLP2 expression by regulating HLP2 transcript APA. Taken together, our results demonstrate that HLP1 and HLP2 bind directly to certain RNA targets to control the selection of poly(A) sites in a synergetic mode to regulate flowering time. The results in this study will shed new light on the role of RBPs-directed RNA processing in plant development.