Journal: Nature Communications
Article Title: METTL9 sustains vertebrate neural development primarily via non-catalytic functions
doi: 10.1038/s41467-025-62414-5
Figure Lengend Snippet: a Experimental strategy for acute METTL9 depletion in Mettl9 Deg mESCs. b Volcano plot of mis-regulated proteins (coloured dots and labels) in dTAG V -1- Mettl9 Deg NSCs over Ctrl (DMSO-treated), by mass spectrometry (q value < 0.05). Y axis indicates log10 FDR-adjusted p values; two-tailed moderated t-statistics. c GO terms of the up-regulated proteins (with a q value < 0.2). Clustering showing significantly enriched GO terms with q value < 0.05. Hypergeometric test; colour scale shows adjusted p values (Benjamini-Hochberg correction). d METTL9 protein: signal peptide (magenta), the glycopeptide position (grey) within sequon (green) and predicted sequon at N86 (aa is amino acid). e WB showing METTL9-DEG in N- (Endo H and PNGase) or O-glycosydase-treated mESCs extracts. Black, green and dark green asterisks (*) are the lowest, intermediate and top METTL9 bands, respectively. Antibodies: anti-FLAG and anti-ACTIN; N = 2 WB and enzymatic treatments. f WB (anti-FLAG, anti-alpha-TUBULIN) showing WT METTL9-FLAG or mutated METTL9-FLAG: N35Q, N35Q;N86Q, and SP* (mutated signal peptide), expressed in WT ESCs. N-glycosylated residues (green); mutated amino acid residues (red); SP (magenta). Asterisks near blot as in ( f ). N = 3 independent experiments. g IF images of Mettl9 Deg NSCs: anti-FLAG (METTL9) and Hoechst (nuclei). Right: a neural rosette. Scale bar: 10 μm. N = 8 fields of view. h IF images of DMSO- (Ctrl) or dTAG V -1-treated Mettl9 Deg NSCs: anti-FLAG antibody showing METTL9. Scale bar: 10 μm. N ≥ 6 fields of view per condition. i IF images of Mettl9 Deg NSCs: anti-FLAG antibody (yellow) for METTL9, GM130 (magenta) for cis -Golgi and Hoechst (cyan) for nuclei. Scale bar: 5 μm. On the right, co-localisation between anti-FLAG and: (i) anti-GM130, (ii) anti-GORASP2 (i and ii for Golgi), (iii) anti-CALRE (ER) or (iv) anti-TOM20 (mitochondria). Boxplot: Manders’ coefficient (M2) indicates co-localization (slices analysed in NO FLAG and FLAG tag, respectively: N = 32, N = 31 (CALRE); N = 35, N = 40, (GM130); N = 35, N = 31 (GORASP2); N = 30, N = 30 (TOM20). P values: above each marker; Wilcoxon test, two-sided. j IF images of Mettl9 Deg /LCS-HA or WT E14 NSCs (DIV5), after Triton or digitonin permeabilization: anti-FLAG antibody (METTL9, yellow), anti-HA (LCS, trans -Golgi lumen, magenta) and Hoechst (nuclei, gray). Scale bar: 10 μm. IFs in ( g – j ) were representative of N ≥ 3 differentiation experiments.
Article Snippet: ES-E14TG2a (E14) mouse embryonic stem cell line (mESC; ATCC), derived from a male 129/Ola mouse blastocyst, were used as wild-type (WT), parental cells.
Techniques: Mass Spectrometry, Two Tailed Test, Glycoproteomics, FLAG-tag, Marker