Fig. 1: Phenotypes of cells lacking the m6A modification in U6 snRNA.
From: A single m6A modification in U6 snRNA diversifies exon sequence at the 5’ splice site
a Primary and secondary structures of U6 snRNA from S. pombe with the following post-transcriptional modifications: CH3OpppG (γ-methyl triphosphate cap), N6-methyladenosine (m6A), 2′O-methylations (Nm), and 2′,3′ cyclic phosphate (>p). 5′SL and ISL represent the 5′ stem loop and internal stem loop, respectively. The underlined sequence represents the ACAGA box. b Loss of m6A in U6 snRNA isolated from SPAC27D7.08c knockout (mtl16Δ) cells. Mass chromatograms of the RNase A-digested fragments of U6 snRNA containing m6A37 or A37 isolated from S. pombe WT and mtl16Δ cells. n.d., not detected. c In vitro reconstitution of m6A in U6 snRNA catalyzed by S. pombe Mtl16 in the presence or absence of SAM. Mass chromatograms of the RNase A-digested fragments of U6 snRNA containing m6A37 or A37. d Growth phenotypes of S. pombe WT and mtl16Δ strains cultured at 30 °C or 37 °C on YE5S plates supplemented with the indicated inducers of cell stress. The plates were photographed 3–4 days after inoculation. TBZ, thiabendazole; HU, hydroxyurea. e Doubling times of WT and mtl16Δ cells were measured in glucose (YE5S) and glycerol media. OD600 was measured every hour for 12 h. The asterisk indicates a statistically significant difference in the doubling time of the two strains, as determined by two-sided Student’s t-test. *p = 7.7e-5; n = 3 biologically independent samples. Data are presented as mean values +/− SD. Source data are provided as a Source Data file. f Northern blotting of S. pombe U snRNAs in total RNA of WT and mtl16Δ cells. 5 S rRNA in total RNA was stained by EtBr as a loading control. Length of each U snRNA is indicated. This result was repeated once with a similar result. Source data are provided as a Source Data file.
