Analysis of the S. pombe meiotic proteome reveals a switch from anabolic to catabolic processes and extensive post-transcriptional regulation

Meiotic progression in S. pombe is regulated by stage-specific gene expression and translation, changes in RNA stability, expression of anti-sense transcripts and targetted proteolysis of regulatory proteins. We have used SILAC labelling to examine the relative levels of proteins in diploid S. pombe cells during meiosis. Among the 3268 proteins quantified at all time points, the level of 880 proteins changed at least two-fold; the majority of proteins showed a stepwise increase or decrease during the meiotic divisions, while some changed transiently. Overall, we observed a reduction in proteins involved in anabolism and an increase in proteins involved in catabolism. We also saw an increase in the level of proteins of the ESCRT-III complex and revealed a role for ESCRT-III components in chromosome segregation and spore formation. Correlation with studies of meiotic gene expression and ribosome occupancy reveals that many of the changes in steady state protein levels are post-transcriptional.

核果蝇（Schizosaccharomyces pombe）的减数分裂进程受特定阶段基因表达与翻译、RNA稳定性变化、反义转录本表达以及调控蛋白的靶向蛋白水解所调控。本研究采用同位素标记技术（SILAC）检测了二倍体核果蝇细胞在减数分裂过程中的蛋白质相对水平。在所有时间点共量化了3268种蛋白质中，有880种蛋白质的水平至少发生了两倍变化；大多数蛋白质在减数分裂过程中呈现逐步增加或减少的趋势，而部分蛋白质则呈现暂时性变化。总体而言，我们发现参与合成代谢的蛋白质水平有所降低，而参与分解代谢的蛋白质水平有所上升。同时，我们还观察到ESCRT-III复合体中蛋白质水平的升高，并揭示了ESCRT-III成分在染色体分离和子囊孢子形成中的作用。与减数分裂基因表达和核糖体占用研究的相关性分析表明，许多稳态蛋白质水平的改变发生在转录后阶段。