Project description:DNA methylation is a key epigenetic modification regulating genome organization, stability, and gene expression. Stable DNA methylation critically relies on methyl groups provided through folate-mediated one-carbon (C1) metabolism, yet the origin and regulation of C1 supply remain elusive. Here we demonstrate that photorespiration serves as a major C1 source for DNA methylation in Arabidopsis. We show that C1 from formate, a photorespiratory byproduct, is incorporated into 5-methyl-cytosine via the reductive cytosolic folate pathway. This occurs predominantly during the day, negatively regulating serine utilization as alternative C1 source. Consequently, suppression of photorespiration under elevated CO₂ levels alters the DNA methylation landscape, an effect exacerbated when regulation of C1 metabolism by the formate-dependent pathway is impaired. Thus, our findings link the fundamental metabolic process of photorespiration to epigenetic stability, highlighting how rising atmospheric CO₂ levels can induce DNA methylation changes.
Project description:In this study we profiled the complete repertoire of 2'-O-methylation sites present in the rRNA and a subset of small RNAs of Leishmania major rRNA using RibOxi-seq.
Project description:Ribosomal RNAs (rRNAs) are main effectors of mRNA decoding, peptide-bond formation and ribosome dynamics during translation. Ribose 2'-O-methylation is the most abundant rRNA chemical modification, and display a complex pattern in rRNA. We globally challenged rRNA 2'-O-Me by inhibiting the rRNA methyl-transferase fibrillarin (FBL) in human cells. Since FBL participates in rRNA processing, we wonder if FBL knockdown could alter the assembly of ribosomes.