1、I. 疾病病理的分子信号概论 II. 呼吸系统疾病的信号调控研究进展 KE, Yuehai 柯越海 Zhejiang University, School of Medicine (ZJUSM) 浙江大学医学院病理与病 理生理 学系 Clinical Pathology Session IIIPersonal Profile http:/ （17年秋冬学期）临床病理学（研究生）周二下午 13：15-15：40 华家池教312 1. 疾病病理的分子信号概论 2 学时 10月10日；11月28日 2. 呼吸系统疾病的分子病理进展 2 学时 10月10日；11月28日 课件下载注意事项： 本网页所有
2、课件链接(PDF) 仅供本校本专业学员教学复习参考，未经许可请勿它用、包 括提供任何第三方链接；除特殊注明之外所有课件文字、数据、图表等均来自公开出版 物，请尊重原作者版权；部分课件有删除或技术处理，教学内容以课堂授课为准。Overview 导论：疾病分子机制与疾 病模型 信号概论：细胞信号与翻 译后修 饰 肺损伤与修复的可逆磷酸 化调控 研究（ 实例）疾病机制与微观研究 解析疾病病因机制的 “分子语言” 解析分子/ 蛋白异常往往是关键、具体科学问题的切入点 信号本质是构成信号蛋白的化学修饰(翻译后修饰) 创新之源：Impossible is nothing but Evidence is e
3、verything 机制研究的思考方式 明确与疾病病因(功能)相关的信号差异性 1. 蛋白表达水平 （最常见，但往往没有差异？ ） 2. 基因水平？转录水平？或 翻译后修饰差异？ 变构、活性（酶）或修饰的差 异（磷 酸化、 乙酰化. ） 3. 蛋白分布的差异（不同组织、细胞） 或者胞 内分布 （上膜 、入核 ） 4. 是否考虑了时间空间（时序）差异？ Example ： Complexity of signal modulator Shp2 in brain system 病因研究的创新点 (1) 被磷酸化修饰的常见氨基酸：酪氨酸、丝氨酸、苏氨酸 (2) 建立基因型与表型关联：临床突变/多态(
4、 基因型) -影响某氨基酸修饰 -蛋白功能-临床表现（表型） 思考点：明确未知蛋白的有意义的修 饰位点 可能是 关键的 科学问 题 疾病模型：相似性与可操 作性平 衡 围绕具体解决的关键问题寻找合适的 模型 ， 永远 没 有最好 只有最 适常见的病因研究策略 Phenotypic observations In vivo cellular signaling events in controlling of pathological alterations via genetically modified animal models Molecular mechanisms Cell-bas
5、ed assays and molecular approaches Human Diseases Epidemiology regulation of gene expression, regulation of protein function, and RNA processing. DNA methylation in vertebrates typically occurs at CpG sites (cytosine-phosphate-guanine sites, that is, where a cytosine is directly followed by a guanin
6、e in the DNA sequence). This methylation results in the conversion of the cytosine to 5-methylcytosine ，by DNA methyltransferase. Protein methylation typically takes place on arginine or lysine amino acid residues in the protein sequence, by peptidylarginine methyltransferases (PRMTs), methylation h
7、as been most studied in the histones. The transfer of methyl groups from S-adenosyl methionine to histones is catalyzed by enzymes known as histone methyltransferases. Histones that are methylated on certain residues can act epigenetically to repress or activate gene expression. Cancer and methylati
8、on imbalanceAcetylation describes a reaction that introduces an acetyl functional group into a chemical compound. (Deacetylation is the removal of the acetyl group.) Acetylation occurs as a co-translational and post- translational modification of proteins, for example, histones, p53, tubulins and ST
9、AT3. Among these proteins, chromatin proteins and metabolic enzymes are highly represented, indicating that acetylation has a considerable impact on gene expression and metabolism. N-terminal Acetylation ： is one of the most common co- translational covalent modifications ， an important role in the
10、synthesis, stability and localization of proteins. Ubiquitination Ubiquitination is a post-translational modification where ubiquitin is attached to a substrate protein. The addition of ubiquitin can affect proteins in many ways: It can signal for their degradation via the proteasome, alter their ce
11、llular location, affect their activity, and promote or prevent protein interactions. Ubiquitin is a small (8.5 kDa) regulatory protein that has been found in almost all tissues (ubiquitously) of eukaryotic organisms, was discovered in 1975. Ubiquitination is carried out in three main steps: activati
12、on, conjugation, and ligation, performed by ubiquitin-activating enzymes (E1s), ubiquitin- conjugating enzymes (E2s), and ubiquitin ligases (E3s). Small Ubiquitin-like Modifier (or SUMO) proteins are a family of small proteins that are covalently attached to and detached from other proteins in cells
13、 to modify their function SUMOylation is a post-translational modification involved in various cellular processes, such as nuclear-cytosolic transport, transcriptional regulation, apoptosis, protein stability, response to stress, and progression through the cell cycle. SUMO proteins are similar to u
14、biquitin, and SUMOylation is directed by an enzymatic cascade analogous to that involved in ubiquitination. In contrast to ubiquitin, SUMO is not used to tag proteins for degradation. Mature SUMO is produced when the last four amino acids of the C-terminus have been cleaved off to allow formation of
15、 an isopeptide bond between the C-terminal glycine residue of SUMO and an acceptor lysine on the target protein. SumoylationPhosphorylation Phosphorylation: A ubiquitous regulatory mechanism in control of molecular events Addition/removal of a phosphate (PO 4 ) group to a protein (Signal regulator),
16、 commonly occurs on serine, threonine and tyrosine. Kinases, Phosphatase and Docking proteinsWhy is Reversible phosphorylation? 1. Most essential chemical reaction leads to alternative conformational switches in enzymes and receptors, causing activated or deactivated action. 2. Most flexible biologi
17、cal response in under less one minute or over hours 3. Most efficient amplified activation, a single kinase molecule can result in the phosphorylation of many proteins.Putative phosphorylation sites and physiological relevancies A signal regulator (protein) have thousand phosphorylation sites, provi
18、ding conformational potentials to change, may or may not (mostly). Each phosphorylation event may have different effects on protein activity, increase, decrease, no effect (mostly). A protein may have diversity of regulatory action for the distinct phosphorylation sites in a given cell at a given ti
19、me, Putative phosphorylation sites Distinctive phosphorylation sites at FAK kinase 1. Growth factors or integrin clustering promotes FAK autophosphorylation at Tyr397, which creates a binding site for SH2 domain of Src. 2. Src-mediated p-Tyr576/577 of FAK results in maximal FAK catalytic activity. 3
20、. FAK phosphorylation at Tyr925 results in Grb2 binding and Erk activaiton 1 2 3- Facts of cellular communications - Signal components and modification Methylation ( 甲基化） Acetylation （乙酰化） Ubiquitination （泛素化） Sumoylation （类泛素化） Phosphorylation ( 磷酸化） - Essential domains - Reversible Phosphorylation
21、 in lungsEssential domains A protein domain is a part of protein sequence and structure that can evolve, function, and exist independently of the rest of the protein chain. Signal molecule proteins may consist of several structural domains. Example: SH2, SH3, PH, PTP A structural motif is a three-di
22、mensional structural element or fold within the chain, which appears also in a variety of other molecules. Motif is sometimes used interchangeably with “structural domain,“ although a domain need not be a motif nor, if it contains a motif, need not be made up of only one. Example: helix-loop-helix, zinc finger, leucine zipper Useful tools for studying signal transduction Functional domains and structural motifsAnthony Tony James Pawson, British-born Canadian scien
