Gene

Cleavage and polyadenylation specificity factor

Function (biology)

Cell biology

Untranslated region

Biology

Messenger RNA

Computational biology

Genetics

Arabidopsis

Abscisic acid

Mutant

Polyadenylation

Gene isoform

Molecular Plant

The biological functions of the epitranscriptomic modification N6-methyladenosine (m6A) in plants are not fully understood. CPSF30-L is a predominant isoform of the polyadenylation factor CPSF30 and consists of CPSF30-S and an m6A-binding YTH domain. Little is known about the biological roles of CPSF30-L and the molecular mechanism underlying its m6A-binding function in alternative polyadenylation. Here, we characterized CPSF30-L as an Arabidopsis m6A reader whose m6A-binding function is required for the floral transition and abscisic acid (ABA) response. We found that the m6A-binding activity of CPSF30-L enhances the formation of liquid-like nuclear bodies, where CPSF30-L mainly recognizes m6A-modified far-upstream elements to control polyadenylation site choice. Deficiency of CPSF30-L lengthens the 3′ untranslated region of three phenotypes-related transcripts, thereby accelerating their mRNA degradation and leading to late flowering and ABA hypersensitivity. Collectively, this study uncovers a new molecular mechanism for m6A-driven phase separation and polyadenylation in plants.

Arabidopsis N6-methyladenosine reader CPSF30-L recognizes FUE signals to control polyadenylation site choice in liquid-like nuclear bodies