Fig. 8: In photoreceptor cells MSI1 and MSI2 act to promote protein expression post-transcriptionally. | Communications Biology

Fig. 8: In photoreceptor cells MSI1 and MSI2 act to promote protein expression post-transcriptionally.

From: The Musashi proteins direct post-transcriptional control of protein expression and alternate exon splicing in vertebrate photoreceptors

Fig. 8

a Scatter plot comparing protein and transcript levels changes after double Msi1/Msi2 knockout in mature photoreceptor cells. Protein expression was quantified by isobaric labeling and mass spectrometry. Transcript expression levels were determined by RNA-Seq. Genes that are highly expressed specifically in photoreceptor cells are shown as rombs and genes highly expressed outside of photoreceptor cells are shown as crosses. Color indicates significant changes in protein levels alone (blue), in mRNA levels alone (green), in both protein and mRNA levels (orange), or no significant change in expression (gray). b Cumulative frequency plots showing the deletion of Msi1/Msi2 in mature photoreceptors leads to broad decrease of photoreceptor protein levels in excess to changes in transcript levels (Kolmogorov–Smirnov p-value = 1.1*10−12). c Western blot analysis of recombinant GNAT1 expression in NIH 3T3 cells. Cells were transfected with equal amounts HA-tagged Gnat1 clone with wild type 3'-UTR and T7-tagged Gnat1 clone with mutant 3'-UTR that lacks Musashi binding sites. Each transfection included one of the following: vector expressing flag-tagged GFP, vector expressing flag-tagged Pcbp2, and vector expressing flag-tagged Msi1. Non transfected cells were included as a control for the specificity of the antibodies. TUBB serves as loading control. Size markers indicate the molecular weight in kDA. d Ratios of the HA (wild type) to T7 (mutant) tagged GNAT1 proteins and ratios of the corresponding RNA transcripts in the transfected NIH 3T3 cells. The data is represented as mean ± SEM of six replicates. The statistical significance of the effect of MSI1 in pairwise comparisons to the controls was determined by Tukey HSD. Significance level is indicated as: *p-value < 0.05, **p-value < 0.01, ***p-value < 0.001. Supplementary Data 15 contains the source data underlying the graph on d. Uncropped blots used underlying the data shown on c, d are shown on Supplementary Fig. 13.

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