N^(6)-methyladenosine(m^(6)A),which is added,removed,and interpreted by m^(6)A writers,erasers,and readers,respectively,is the most abundant modification in eukaryotic mRNAs.The m^(6)A marks play a pivotal role in the...N^(6)-methyladenosine(m^(6)A),which is added,removed,and interpreted by m^(6)A writers,erasers,and readers,respectively,is the most abundant modification in eukaryotic mRNAs.The m^(6)A marks play a pivotal role in the regulation of floral transition in plants.FLOWERING LOCUS K(FLK),an RNA-binding protein harboring K-homology(KH)motifs,is known to regulate floral transition by repressing the levels of a key floral repressor FLOWERING LOCUS C(FLC)in Arabidopsis.However,the molecular mechanism underlying FLK-mediated FLC regulation remains unclear.In this study,we identified FLK as a novel mRNA m^(6)A reader protein that directly binds the m^(6)A site in the 3ʹ-untranslated region of FLC transcripts to repressing FLC levels by reducing its stability and splicing.Importantly,FLK binding of FLC transcripts was abolished in vir-1,an m^(6)A writer mutant,and the late-flowering phenotype of the flk mutant could not be rescued by genetic complementation using the mutant FLKm gene,in which the m^(6)A reader encoding function was eliminated,indicating that FLK binds and regulates FLC expression in an m^(6)A-dependent manner.Collectively,our study has addressed a long-standing question of how FLK regulates FLC transcript levels and established a molecular link between the FLK-mediated recognition of m^(6)A modifications on FLC transcripts and floral transition in Arabidopsis.展开更多
基金supported by grants from the Mid-Career Researcher Program through the National Research Foundation of Korea,funded by the Ministry of Science,ICT and Future Planning(NRF-2021R1A2C1004187)Republic of Korea,and the New Breeding Technologies Development Program(PJ01652401)Rural Development Administration,Republic of Korea(to H.K.).
文摘N^(6)-methyladenosine(m^(6)A),which is added,removed,and interpreted by m^(6)A writers,erasers,and readers,respectively,is the most abundant modification in eukaryotic mRNAs.The m^(6)A marks play a pivotal role in the regulation of floral transition in plants.FLOWERING LOCUS K(FLK),an RNA-binding protein harboring K-homology(KH)motifs,is known to regulate floral transition by repressing the levels of a key floral repressor FLOWERING LOCUS C(FLC)in Arabidopsis.However,the molecular mechanism underlying FLK-mediated FLC regulation remains unclear.In this study,we identified FLK as a novel mRNA m^(6)A reader protein that directly binds the m^(6)A site in the 3ʹ-untranslated region of FLC transcripts to repressing FLC levels by reducing its stability and splicing.Importantly,FLK binding of FLC transcripts was abolished in vir-1,an m^(6)A writer mutant,and the late-flowering phenotype of the flk mutant could not be rescued by genetic complementation using the mutant FLKm gene,in which the m^(6)A reader encoding function was eliminated,indicating that FLK binds and regulates FLC expression in an m^(6)A-dependent manner.Collectively,our study has addressed a long-standing question of how FLK regulates FLC transcript levels and established a molecular link between the FLK-mediated recognition of m^(6)A modifications on FLC transcripts and floral transition in Arabidopsis.
