GSE39051
Integrative genome-wide analysis reveals HLP1, a novel RNA-binding protein, regulates plant flowering by targeted alternative polyadenylation
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, an hnRNP A/B protein as a novel regulator for pre-mRNA 3’ end processing in Arabidopsis. Genetic analysis reveals that HLP1 suppresses Flowering Locus C (FLC), a key repressor of flowering in Arabidopsis. 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 a role in 3’-end formation. We show significantly enriched binding of HLP1 to transcripts involved in RNA metabolism and flowering. Comprehensive profiling of the poly(A) site usage reveals that HLP1 mutations cause thousands of poly(A) site shifts. A distal-to-proximal poly(A) site shift in the flowering regulator FCA, a direct target of HLP1, further leading to up-regulated FLC and delayed flowering. Our results elucidate that HLP1 is a novel factor involved in 3’ end processing and controls reproductive timing via targeted APA. Overall design: Investigate the role of HLP1 in Alternative Polyadenylation Contributed by: The Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences