酵母蛋白组量化研究.doc

酵母蛋白组量化研究 研究人员将单倍体细胞中这些蛋白的水平与双倍体细胞中它们的水平进行了对比。除了其他差别之外，双倍体中细胞壁成分的含量也显著降低，这与双倍体比单倍体大两倍、但并没有两倍大的表面积这一事实是一致的。 1 Proteomics and Signal Transduction, and, 2 Organelle Architecture and Dynamics, Max-Planck-Institute for Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany 3 These authors contributed equally to this work. （/zt/focus/ 生物热点研究） Mass spectrometry is a powerful technology for the analysis of large numbers of endogenous proteins1, 2. However, the analytical challenges associated with comprehensive identification and relative quantification of cellular proteomes have so far appeared to be insurmountable3. Here, using advances in computational proteomics, instrument performance and sample preparation strategies, we compare protein levels of essentially all endogenous proteins in haploid yeast cells to their diploid counterparts. Our analysis spans more than four orders of magnitude in protein abundance with no discrimination against membrane or low level regulatory proteins. Stable-isotope labelling by amino acids in cell culture (SILAC) quantification4, 5 was very accurate across the proteome, as demonstrated by one-to-one ratios of most yeast proteins. （/news/ 生物研究新闻） Key members of the pheromone pathway were specific to haploid yeast but others were unaltered, suggesting an efficient control mechanism of the mating response. Several retrotransposon-associated proteins were specific to haploid yeast. Gene ontology analysis pinpointed a significant change for cell wall components in agreement with geometrical considerations: diploid cells have twice the volume but not twice the surface area of haploid cells. Transcriptome levels agreed poorly with proteome changes overall. However, after filtering out low confidence microarray measurements, messenger RNA changes and SILAC ratios correlated very well for pheromone pathway components. Systems-wide, precise quantification directly at the protein level opens up new perspectives in post-genomics and syste