Yeast meiotic proteome in wildtype versus kar4 mutant
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ABSTRACT: The Kar4 protein has been identified as being a component of the yeast N6A mRNA methyltransferase, homologous to human METTL14. Mutations in KAR4 cause blocks in meiosis due to 1) reduced expression of Ime1p-induced transcripts, and 2) reduced levels of a subset of meiotic proteins, independent of their transcript levels. The reduced levels of the proteins are partially suppressed by increased levels of a translational regulator, Rim4. This proteomic study was aimed at identifying the spectrum of meiotic proteins affected by the absence of Kar4. The defect in Ime1p-depedent transcription was suppressed by over-expression of Ime1p. Proteins present in wildtype and kar4 deletion strains at two different times in meiosis were fractionated using reverse-phase chromatography and identified by MS/MS. Some 4068 proteins expressed during meiosis were identified. At 8 hours, 432 proteins were present at less than 50% the levels in kar4Δ/Δ compared to wild type. GO term analysis of the low proteins at 8 hours returned “meiotic cell cycle” as the sixth term with a P value of 7.74x10^-5. At 12 hours, 318 proteins were present at less than 50% the levels in kar4Δ/Δ relative to wild type. GO term analysis returned “meiotic cell cycle” as the second term with a P value less than 0.001. Proteins that were low at both 8 and 12 hours in kar4∆/∆ comprise proteins required for meiotic recombination and sporulation including Sps2p, Gas4p, Gmc2p, Mei5p, and Sae3p. Other meiotic proteins were expressed at or above wild type levels at 8 hours, but went down to lower than wild type levels at 12 hours, including Ecm11p, Hed1p, Spo11p, and Rec8p. In each case the levels of the proteins were reduced to much greater extents that can be explained by changes in transcript levels. Taken together these data suggest that Kar4 plays a role in the regulation of transcription and translation during yeast meiosis.
INSTRUMENT(S): Q Exactive HF
ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)
TISSUE(S): Meiosis Ii
SUBMITTER: Mark Rose
LAB HEAD: Mark D. Rose
PROVIDER: PXD043798 | Pride | 2023-08-22
REPOSITORIES: Pride
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