第五章物质的跨膜运输(王喜忠邹方东细胞生物学全套).ppt

由细胞表面整合蛋白介导的信号传递 ●整合蛋白与粘着斑 ●导致粘着斑装配的信号通路有两条 ●粘着斑的功能： ?一是机械结构功能； ?二是信号传递功能 ●通过粘着斑由整合蛋白介导的信号传递通路： ?由细胞表面到细胞核的信号通路 ?由细胞表面到细胞质核糖体的信号通路 细胞信号传递的基本特征与蛋白激酶的网络整合信息 ●细胞信号传递的基本特征： ?具有收敛（convergence）或发散（divergence）的特点 ?细胞的信号传导既具有专一性又有作用机制的相似性 ?信号的放大作用和信号所启动的作用的终止并存 ?细胞以不同的方式产生对信号的适应 ●蛋白激酶的网络整合信息与信号网络系统中的cross talk Transport processes within an eukaryotic cell The plasma membrane is a selectively permeable barrier: The phospholipid bilayer is impermeable to most water-soluble molecules. Transport of such molecules is mediated by Transport Proteins. Diffusion of small molecules across phospholipid bilayers 简单扩散与协助扩散的比较 Comparison of passive and active transport If uncharged solutes are small enough, they can move down their concentration gradients directly across the lipid bilayer by simple diffusion. Most solutes can cross the membrane only if there is a membrane transport protein to transfer them. Passive transport, in the same direction as a concentration gradient; Active transport, against a concentration gradient, require an input of energy. Gated ion channels: The gates open in response to a change in the voltage difference, to the binding of a chemical ligand, or to mechanical stimulation 在动物、植物细胞由载体蛋白 介导的协同运输异同点的比较 Na+-linked symporters import amino acids and glucose into many animal cells Na+-linked antiporter exports Ca+ from cardiac muscle cells Medicine Oubain and digoxin increase the force of heart muscle contraction by inhibiting the Na+/K+ ATPase. Fewer Ca+ ions are exported Structure of a clathrin –coated vesicle (A) 细胞内受体蛋白作用模型; (B) 几种胞内受体蛋白超家族成员 Transport Across Cell Membrane, Cell Signal Transduction ? 物质的跨膜运输 ? 细胞通讯与信号传递 Chapter 5 Section 1 Transport Across Cell Membrane ●简单扩散(simple diffusion) ●被动运输（passive transport） ●主动运输（active transport） ●胞吞作用endocytosis与胞吐作用exocytosis 物质的跨膜运输是细胞维持正常生命活动的基础之一。 Section 2 Cell Signaling ●细胞通讯与细胞识别 ●细胞的信号分子与受体 ●通过细胞内受体介导的信号传递 ●通过细胞表面受体介导的信号跨