小蛋白质富集法鉴定酿酒酵母“漏检蛋白”

Identification of missing proteins in Saccharomyces cerevisiae by small protein-based enrichment

摘要:

小蛋白质 (Small proteins，SPs) 是由小开放阅读框 (Short open reading frames，sORFs) 编码长度小于100个氨基酸的多肽。研究发现小蛋白质参与了基因表达调控、细胞信号转导和代谢等重要生物学过程。然而，生命体中大多数的已注释小蛋白质尚缺少蛋白水平存在的实验证据，被称为漏检蛋白 (Missing proteins，MPs)。小蛋白质的高效鉴定是其功能研究的前提，也有助于挖掘“漏检蛋白”。文中采用小蛋白质富集策略鉴定到72个酵母小蛋白质，验证9个“漏检蛋白”，发现低分子量、高疏水性、膜结合、弱密码子使用偏性及不稳定性是蛋白漏检的主要原因，对进一步的技术优化具有指导意义。

关键词:蛋白质组学，小蛋白质，富集，漏检蛋白

Abstract:

Small proteins (SPs) are defined as peptides of 100 amino acids or less encoded by short open reading frames (sORFs). SPs participate in a wide range of functions in cells, including gene regulating, cell signaling and metabolism. However, most annotated SPs in all living organisms are currently lacking expression evidence at the protein level and regarded as missing proteins (MPs). High efficient SPs identification is the prerequisite for their functional study and contribution to MPs searching. In this study, we identified 72 SPs and successfully validated 9 MPs from Saccharomyces cerevisiae based on SPs enrichment strategy. In-depth analysis showed that the missing factors of MPs were low molecular weight, low abundant, hydrophobicity, lower codon usage bias and unstable. The small protein-based enrichment can be used as MPs searching strategy, which might provide the foundation for their further function research.

Key words:proteomics, small protein, enrichment, missing protein