Distinct temporal requirements for autophagy and the proteasome in yeast meiosis

Abstract

Meiosis is a special type of cellular renovation that involves 2 successive cell divisions and a single round of DNA replication. Two major degradation systems, the autophagy-lysosome and the ubiquitin-proteasome, are involved in meiosis, but their roles have yet to be elucidated. Here we show that autophagy mainly affects the initiation of meiosis but not the nuclear division. Autophagy works not only by serving as a dynamic recycling system but also by eliminating some negative meiotic regulators such as Ego4 (Ynr034w-a). In a quantitative proteomics study, the proteasome was found to be significantly upregulated during meiotic divisions. We found that proteasomal activity is essential to the 2 successive meiotic nuclear divisions but not for the initiation of meiosis. Our study defines the roles of autophagy and the proteasome in meiosis: Autophagy mainly affects the initiation of meiosis, whereas the proteasome mainly affects the 2 successive meiotic divisions.

Slx5p‐Slx8p Promotes Accurate Chromosome Segregation by Mediating the Degradation of Synaptonemal Complex Components during Meiosis

“…Sporulation Conditions and Meiotic Nuclear Division Assays : Sporulation was induced using potassium acetate as previously described . The strains were grown for 24 h in YPD medium (1% yeast extract, 2% peptone, and 2% glucose), diluted in liquid YPA medium (1% yeast extract, 2% peptone, and 2% potassium acetate) to OD600 = 0.3, and grown for 10 h at 30 °C.…”

Proteomic Analysis of Dpy19l2‐Deficient Human Globozoospermia Reveals Multiple Molecular Defects

“…Peptides were detected in a hybrid dual‐cell quadrupole linear ion trap‐orbitrap mass spectrometer (LTQ Orbitrap Velos, Thermo Fisher Scientific, Waltham, MA, USA) using a data‐dependent Top8‐MS2/MS3 method. The MS parameters were set as previously reported …”

“…The relative protein abundance ratios of the two groups were calculated from TMT reagent reporter ion intensities from HCD spectra using the Libra algorithm . A protein was considered statistically differentially expressed if the p ‐value was < 0.05 using Student's t ‐test and the fold‐change in mean expression between the groups was higher than two.…”

A Comparative Proteome Profile of Female Mouse Gonads Suggests a Tight Link between the Electron Transport Chain and Meiosis Initiation

“…Peptides were detected with a hybrid dual-cell quadrupole linear ion trap-orbitrap mass spectrometer (LTQ Orbitrap Velos, Thermo Fisher Scientific, Waltham, MA) using a data-dependent Top8-MS3 method as previously described (21). For each cycle, one full MS scan of mass/charge ratio (m/z) ϭ 400 to 1800 was acquired in the Orbitrap at a resolution of 30,000 or 60,000.…”

“…4 biological replicates were used in each stage. For identification of differentially expressed (DE) proteins among stages, a protein with a fold change greater than 2 and a false discovery rate (Q value) less than 0.01 by the SAM (Significance Analysis of Microarrays) algorithm in J-Express (31) were considered significant (16,21). For gonad culture, gonads were cultured in medium containing ROT (0.1 M) or ROT (0.1 M) adding CoQ10 (20 M) for 24 h followed by culture in their normal medium, gonads were collected at 14.5 dpc for further study.…”