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Signal transduction signal transduction system composes: receptor, enzyme,pathway regular protein function:. Overview of cellular signals (1) recognition of extra cellular signaling molecules A. produce of signaling molecules.
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Signal transduction signal transduction system composes: receptor, enzyme,pathway regular protein function:
Overview of cellular signals • (1) recognition of extra cellular • signaling molecules • A. produce of signaling • molecules
B. Chemical properties of • signaling molecules • Function of signaling molecules • D. Characters of signaling molecules • a. receptors • *concept
(2). effective pathway of secreting signaling molecules A.endocrine B.paracrine C.synapse D.autocrine E.gap junction
* characters 2. Membrane-bound receptors A.types a.ion- channel- linked receptor b.G- protein-linked linked receptor c. enzyme-linked receptor B.function
ion- channel- linked receptor • * function • * characters • * instance
b.G- protein-linked linked receptor c. enzyme-linked receptor * function * characters
3. Signal transduction mediated by G protein linked receptors A.family of G-protein linked receptors a. structure b.character
B. Trimeric GTP -binding protein a.structure b.character c.function *concept of second messengers
信号分子与G蛋白联系型受体膜外区域结合 生物学效应 G蛋白联系型受体膜内区域与G蛋白结合 靶蛋白活性变化 G蛋白活性改变 细胞内小分子信号分子浓度变化(细胞内介导物,细胞内信使) 第二信使,如Ca2+ , cAMP 酶活性改变
C. Signaling transduction system via cAMP a. Control of cAMP concentration by G protein linked receptor to regulated activity of adenylate cyclase # Formation of cAMP
Material : ATP Enzyme: adenylate cyclase catalytic reaction: ATP cAMP
characters ( Gs & Gi ) # Degradation of cAMP b. How to activated adenylate cyclase by G protein linked receptor
c. Effect of cAMP mediated by cAMP dependent protein kinase * the effect of cAMP * the effect of kinase A * the structure of kinase A
* The process of activation of • kinase A • Example • kinase A also can activated • transcription of other special • genes
D. Signal transduction system mediated by Ca 2+ a . inositol phospholipid signalling activated by G- protein linked receptor
b. the formation of inositol phospholipid c. the location of inositol phospholipid d. inositol concerned signal transduction PIP,PIP2
e. the pathway of signal transduction C. The fuction of IP3 & DG a. the fuction of IP3 b. the function of DG the facts needed to activate PKc D.The function of calmodulin
a. The structure • b. the functure
4 . Signal transduction mediated by enzyme linked receptor (1) type (2) character
(3) Receptor guanylyl cyclase system A. Character (4) Receptor tyrosine kinase system a. receptor tyrosine kinase b. the machanism of activation of Tyr kinase
b.other components # proteins with SH domain # SOS protein # Ras protein # downstream mediators of Ras protein
(5). Tyrosin-kinase associated receptors A.JAK-STAT signalling pathway a.JAK kinase
# Structure # Function # Character b. STAT # function
Signal transduction • mediated by fat-soluble extracellular signalling molecules • A. character • B. two domains
C. mechanism of regulation of gene expression
信号细胞 分泌 信号分子 细胞膜 细胞膜结合 作用于其它细胞(靶细胞)
信号分子(配体ligand) 靶细胞膜外受体蛋白 扩散进入 结合 靶细胞膜内受体蛋白 结合 启动靶细胞内信号转导 系统级联式反应 受体—信号分子 复合体 靶细胞内生物学效应
受体+配体 受体变构 离子通道关闭或开放 阴、阳离子流动增加或减少 传递信息
cAMP α2受体 Gi 肾上腺素 受体 β2受体 Gs cAMP
αs与AC结合 αs所具有的GTP酶活性升高 使与之结合的GTP转变为GDP αs、AC活性均下降 αs与β、γ肽链结合 重新形成不具活性的 三聚体GTP-结合蛋白
受体与胞外信号分子结合 Gi活化 αi与GTP结合 并从三聚体中解离 与AC结合抑制其活性 αi βγ复合物 与解离的αs结合阻止 间接抑制AC 其激活AC