Project description:N6-methyladenosine (m6A) represents the most prevalent internal modification on messenger RNA, and requires a multicomponent m6A methyltransferase complex in mammals. How their plant counterparts determine the global m6A modification landscape and its molecular link to plant development remain elusive. Here we show that FKBP12 INTERACTING PROTEIN 37 KD (FIP37) is a core component of the m6A methyltransferase complex, which underlies control of shoot stem cell fate in Arabidopsis. The mutants lacking FIP37 exhibit massive overproliferation of shoot meristems and a transcriptome-wide loss of m6A RNA modifications. We further demonstrate that FIP37 mediates m6A RNA modification on key shoot meristem genes inversely correlated with their mRNA stability, thus confining their transcript levels to prevent shoot meristem overproliferation. Our results suggest an indispensable role of FIP37 in mediating m6A mRNA modification, which is required for maintaining the shoot meristem as a renewable source for continuously producing all aerial organs in plants. RNA-seq in Arabidopsis thaliana (Col-0) wild-type and fip37-4 LEC1:FIP37, three replicates for each sample
Project description:N6-methyladenosine (m6A) represents the most prevalent internal modification on messenger RNA, and requires a multicomponent m6A methyltransferase complex in mammals. How their plant counterparts determine the global m6A modification landscape and its molecular link to plant development remain elusive. Here we show that FKBP12 INTERACTING PROTEIN 37 KD (FIP37) is a core component of the m6A methyltransferase complex, which underlies control of shoot stem cell fate in Arabidopsis. The mutants lacking FIP37 exhibit massive overproliferation of shoot meristems and a transcriptome-wide loss of m6A RNA modifications. We further demonstrate that FIP37 mediates m6A RNA modification on key shoot meristem genes inversely correlated with their mRNA stability, thus confining their transcript levels to prevent shoot meristem overproliferation. Our results suggest an indispensable role of FIP37 in mediating m6A mRNA modification, which is required for maintaining the shoot meristem as a renewable source for continuously producing all aerial organs in plants. m6A-seq in Arabidopsis thaliana (Col-0) wild-type and fip37-4 LEC1:FIP37, two replicates for each sample
Project description:N6-methyladenosine (m6A) is the most prevalent internal modification found in mammalian messenger and non-coding RNAs. The discoveries of functionally significant demethylases that reverse this methylation as well as the recently revealed m6A distributions in mammalian transcriptomes strongly indicate regulatory functions of this modification. Here we report the identification and characterization of the mammalian nuclear RNA N6-adenosine methyltransferase core (RNMTC) complex. Besides METTL3, a methyltransferase which was the only known component of RNMTC in the past, we discovered that a previously uncharacterized methyltransferase, METTL14, exhibits a N6-adenosine methyltransferase activity higher than METTL3. Together with WTAP, the third component that dramatically affects the cellular m6A level, these three proteins form the core complex that orchestrates m6A deposition on mammalian nuclear RNA. Biochemistry assays, imaging experiments, as well as transcriptome-wide analyses of the binding sites and their effects on m6A methylation support methylation function and reveal new insights of RNMTC. PAR-CLIP and m6A-seq in HeLa cells
Project description:N6-methyladenosine (m6A) is the most abundant internal modification in the messenger RNA (mRNA) of all higher eukaryotes. This modification has been shown to be reversible in mammals; it is installed by a methyltransferase heterodimer complex of METTL3 and METTL14 bound with WTAP, and reversed by iron(II)- and α-ketoglutarate-dependent demethylases FTO and ALKBH5. This modification exhibits significant functional roles in various biological processes. The m6A modification as a RNA mark is recognized by reader proteins, such as YTH domain family proteins and HNRNPA2B1; m6A can also act as a structure switch to affect RNA-protein interactions for biological regulation. In Arabidopsis thaliana, the methyltransferase subunit MTA (the plant orthologue of human METTL3, encoded by At4g10760) was well characterized and FIP37 (the plant orthologue of human WTAP) was first identified as the interacting partner of MTA. Here we report the discovery and characterization of reversible m6A methylation mediated by AtALKBH10B (encoded by At4g02940) in A. thaliana, and noticeable roles of this RNA demethylase in affecting plant development and floral transition. Our findings reveal potential broad functions of reversible mRNA methylation in plants. m6A peaks were identified from wild type Columbia-0 and atalkbh10b-1 mutant in two biological replicates