The Schizosaccharomyces pombe mgU6-47 gene is required for 2'-O-methylation of U6 snRNA at A41.
Through a computer search of DNA databases, we have identified the homologs of the mgU6-47 snoRNA gene from the yeast Schizosaccharomyces pombe, the fly Drosophila melanogaster and human. The three box C/D-containing snoRNA genes showed no significant similarity in their sequences except for an 11 nt long complementarity to U6 snRNA, suggesting that the mechanism of snoRNA guided snRNA methylation is conserved from mammals to yeast. The corresponding snoRNAs have been positively detected by reverse transcription and northern blotting. Taking advantage of the fission yeast system, we have disrupted the yeast mgU6-47 gene and demonstrated that it is absolutely required for site-specific 2'-O-methylation of U6 at position A41. No growth differences between mgU6-47 gene-disrupted and wild-type cells were observed, suggesting that the mgU6-47 gene, as for most rRNA methylation guides, is dispensable in yeast. Nevertheless, it was revealed by temperature shift assay that abolition of A41 methylation in yeast U6 snRNA might cause a small decrease in mRNA splicing efficiency. The timing of S.pombe U6 pre-RNA transport in the nucleus for splicing and methylation was also analyzed and is described.
Zhou
Hui
H
Key Laboratory of Gene Engineering of the Ministry of Education, Biotechnology Research Center, Zhongshan University, Guangzhou 510275, People's Republic of China.
Chen
Yue-Qin
YQ
Du
Yan-Ping
YP
Qu
Liang-Hu
LH
D021581:Active Transport, Cell Nucleus; D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D002466:Cell Nucleolus / Q000378:metabolism; D017124:Conserved Sequence; D004331:Drosophila melanogaster / Q000235:genetics; D005800:Genes, Fungal; D006801:Humans; D007700:Kinetics; D008745:Methylation; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D012323:RNA Processing, Post-Transcriptional; D012326:RNA Splicing; D012342:RNA, Small Nuclear / Q000737:chemistry* / Q000378:metabolism*; D020537:RNA, Small Nucleolar / Q000235:genetics / Q000502:physiology*; D012568:Schizosaccharomyces / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D000227:Adenine Nucleotides; D012342:RNA, Small Nuclear; D020537:RNA, Small Nucleolar; C405486:U6 small nuclear RNA