1. Three cell communication ways and their extracellular signaling molecules 1) Signaling by secreted molecules-soluble signaling molecules, including proteins, small peptides, amino acids, nucleotedes, steroids, retinoids, fatty acid derivatives, and even dissolved gases such as NO, CO 2)Signaling by plasma-membrane-bound molecules between cell and cell or between cell and their stratum insoluble signaling molecules, including ECM, SAMS and cams 3) Electric coupling by cell communication junctions 2. Secreted signal molecules mediate four forms of signaling, rather than signaling by plasma-membrane bound molecules
1.Three cell communication ways and their extracellular signaling molecules 1) Signaling by secreted molecules-soluble signaling molecules, including proteins, small peptides, amino acids, nucleotedes, steroids, retinoids, fatty acid derivatives, and even dissolved gases such as NO, CO. 2) Signaling by plasma-membrane-bound molecules between cell and cell or between cell and their stratuminsoluble signaling molecules, including ECM, SAMs, and CAMs. 3) Electric coupling by cell communication junctions 2. Secreted signal molecules mediate four forms of signaling, rather than signaling by plasma-membranebound molecules
(A)endocrine, hormone(B) paracrine, local mediators C)autocrine, to coordinate decisions by groups of identical cells;(D) synaptic, neurotransmitters(high concen- tration M, low affinity) (A)内分泌 (B)旁分泌 内分泌细胞 受体 信号细胞 激素 靶细胞 2局部介质 血流 靶细胞(③ (C)自分泌 D)化学突触 神经元 突触 ⊙ 胞体神经递质 靶细 E)接触依赖性通讯 信号细胞靶细胞 (E)signaling by esf e plasma membrane 膜结合信号分子 bound molecules
(A) endocrine, hormone (B) paracrine, local mediators; (C) autocrine, to coordinate decisions by groups of identical cells; (D) synaptic, neurotransmitters (high concen- tration ~ 5x10-4 M, low affinity). (E) signaling by plasma membranebound molecules
A) Endocrine signaling Circulatory system B) Paracrine signaling 或 C Direct cell-to-cell signaling D) Autocrine signaling
Ligand (primary messenger) Receptor CYTOSOL Receptor-ligand binding 3)Cellular responses NUCLEUS Signal transduction (via second messengers) (4)Changes in gene expression Figure 10-2 The Overall Flow of Information During Cell Signaling Binding of ligand by a receptor activates a series of events known as signal transduction, which relays the signal to the interior of the cell, resulting in specific cellular responses and/or changes in gene expression
3. Signaling system composition 1) Simple signaling pathway by an extracellular signal (1).Small effective molecules mediated signaling (called as secondary messenger) The secondary messengers are generated from (2) Signaling pathway via lager intracellular signaling molecules(proteins or enzymes) rather than secondary messenger
3. Signaling system composition 1) Simple signaling pathway by an extracellular signal (1) Small effective molecules mediated signaling (called as secondary messenger) The secondary messengers are generated from (2) Signaling pathway via lager intracellular signaling molecules (proteins or enzymes) rather than secondary messenger