不同营养条件下酿酒酵母中线粒体相关的内质网膜的蛋白质组鉴定

Proteomic Study of Mitochondria-Associated Endoplasmic Reticulum in Saccharomyces cerevisiae under Different Nutritional Conditions

线粒体相关的内质网膜(mitochondria-associated endoplasmic reticulum, MAM)是细胞的重要组成部分,在细胞生理活动中起着关键的调控作用,但目前还缺少对酵母中该组分蛋白质的系统性分析。本研究对不同营养条件下酵母中MAM蛋白进行了全面的蛋白质组学鉴定,最终得到1 486个MAM组分蛋白。差异蛋白分析发现,在饥饿条件下,共有176个差异蛋白,其中上调蛋白39个,下调蛋白137个;在过营养条件下,共有158个差异蛋白,其中上调蛋白155个,下调蛋白3个。功能富集分析结果表明,这些蛋白主要参与糖的生物合成、脂肪酸代谢、类固醇生物合成代谢、内质网的蛋白质加工、氨基酸的生物合成等过程。相互作用网络分析发现了固醇合成和蛋白质加工的具体通路,以及关键的MAM组分蛋白,如MCD4和CNE1等。本研究不仅鉴定到新的MAM组分蛋白,还为进一步探索其生物学功能提供了重要的数据支持和理论依据。

The mitochondrial-associated endoplasmic reticulum membrane(MAM)is an essential component of eukaryotic cells.It is involved in many critical cellular functions,such as bioenergetics,mitophagy,apoptosis,and calcium signaling,regulating cellular physiological activities.The MAM proteins of mammalian cells have been extensively studied.However,as an important model organism of eukaryotic single cell,only a few MAM proteins were found in yeast,named endoplasmic reticulum and mitochondria encounter structures(ERMES).There is currently a lack of systematic analysis of MAM protein in yeast.Here,the MAM proteins in Saccharomyces cerevisiae that grow under different nutritional conditions were comprehensively identified by using Percoll gradient differential centrifugation and label-free quantification mass spectrometry technique.Finally,1486 MAM component proteins are obtained,including well-known MAM proteins and more new components.The functional enrichment analysis of these proteins showed that they are mainly enriched in protein synthesis and transport,glucose metabolism,and lipid metabolism.They are located primarily in the endoplasmic reticulum,mitochondria,Golgi apparatus,and other organelles.Their molecular functions are mainly related to transferase,oxidoreductase activity,proton-transporting ATPase activity,and protein and lipid binding.KEGG metabolic pathway analysis indicated that these proteins participate in sugar biosynthesis,fatty acid metabolism,steroid biosynthesis,endoplasmic reticulum protein processing,amino acid biosynthesis,and other processes.Under different nutritional conditions,the proteins related to mitochondrial division and fusion were identified,such as CAF4,FIS1,DNM1,FZO1 and UGO1.Except for regulatory effects on the structure of mitochondrial,the MAM proteins also have other functions,such as vesicular transport(SSO2,GOS1,VAM6),ion transport(RSN1,YVC1,ATP18),sterol synthesis(ERG1,ERG2,ERG3)and autophagy(ATG39,ATG15,ATG22).Through differential expression analysis,176 differentially expressed proteins(DEPs)are found under starvation conditions,including 39 up-regulated and 137 down-regulated proteins;158 DEPs are found under overnutrition conditions,including 155 up-regulated and 3 down-regulated proteins.By analyzing the protein-protein interaction network of DEPs,it was found that they are mainly involved in the biosynthesis of sugars,proton-transporting ATPase activity,GPI-anchored protein biosynthesis,steroid biosynthesis,protein processing in the endoplasmic reticulum,and mitochondrial redox reactions.The pathways and critical proteins involved in sterol synthesis and protein processing were determined,such as MCD4 and CNE1.This research provides significant data resources for further exploring the biological functions of MAM proteins and helps to understand their roles during the process of cellular stress.