RNAs are post-transcriptionally modified. Among these modifications, base methylations are highly conserved in eukaryotic rRNAs. Recently, yeast ribosomal RNA processing protein 8 (Rrp8) and mammalian nucleomethylin (NML) were identified as factors mediating N1-methyladenosine (
m1A) modification in yeast 25S and mammalian 28S rRNA, respectively. However,
m1A modification of rRNA in Caenorhabditis elegans (C. elegans) is not fully understood. Database searching for C. elegans protein showed that T07A9.8 is a putative homolog of yeast Rrp8 and mammalian NML protein. We performed an RNA immunoprecipitation assay to investigate the role of T07A9.8 in the
m1A modification of 26S rRNA. Results demonstrated that
m1A modifications occurred around A674 of 26S rRNA and that T07A9.8 was involved in the methylation. Next, we performed a site-specific RT-qPCR, which showed that T07A9.8 protein is responsible for
m1A modification at position 674 in 26S rRNA. This
m1A modification site in C. elegans corresponds to those in yeast 25S and mammalian 28S rRNA genes. Since
m1A modification of 26S rRNA in C. elegans requires T07A9.8, we named the T07A9.8 gene as
rram-1 (rRNA adenine methyltransferase-1).