胞科学 ell Science 蔡国平
细胞科学 Cell Science （13） 蔡国平
8 13 Cell signaling: communication between cells and their environment I Cell communication and what is cell signaling 2. Some of the basic characteristics of cell signaling systems 3. Main classes of cell-surface receptor proteins for secreted signaling molecules 4. G-protein-coupled cell-surface receptor-mediated cell signaling system 5. Receptor tyrosine kinases(RTKS): The receptors for most grow yth factors 6. Signaling that originate from cell-surface contact 7. Convergence, divergence and crosstalk among different signaling pathways and target-cell adaptation to a signaling ligand
§13. Cell signaling: communication between cells and their environment 1 Cell communication and what is cell signaling 2. Some of the basic characteristics of cell signaling systems 3. Main classes of cell-surface receptor proteins for secreted signaling molecules 4. G-protein-coupled cell-surface receptor-mediated cell signaling system 5. Receptor tyrosine kinases(RTKs): The receptors for most growth factors 6. Signaling that originate from cell-surface contact 7 . Convergence, divergence and crosstalk among different signaling pathways and target-cell adaptation to a signaling ligand
13. Cell signaling: communication between cells and their environment 13. 1 Cell communication and what is cell signaling For multi-cellular organisms, in addition to the transporting and exchange of material between cells, it is also essential for cell survival and their activities that cells communicate with their neighbors, monitor the conditions in their environment, and respond appropriately to a host of different types of stimuli that impinge on their surface Cells carry out these interactions by the mechanism known as cell signaling, in which information is relayed across the plasma membrane to the cell interior and often to the cell nucleus and these cell communication or signaling depend heavily on extracellular signal molecules or signals ( special domains or motifs )existing in extra-cellular macromolecules
13. Cell signaling: communication between cells and their environment 13.1 Cell communication and what is cell signaling For multi-cellular organisms, in addition to the transporting and exchange of material between cells, it is also essential for cell survival and their activities that cells communicate with their neighbors, monitor the conditions in their environment, and respond appropriately to a host of different types of stimuli that impinge on their surface. Cells carry out these interactions by the mechanism known as cell signaling, in which information is relayed across the plasma membrane to the cell interior and often to the cell nucleus and these cell communication or signaling depend heavily on extracellular signal molecules or signals (special domains or motifs ) existing in extra-cellular macromolecules
Actually, Cell communi- cation between single cell organisms also occurs by similar but much more simple mechanism,for example. yeast cells to be matting secrete some signal (A) molecules. which are as chemotactic factors to attract each other and mat (B)
Actually, Cell communication between single cell organisms also occurs by similar but much more simple mechanism , for example, yeast cells to be matting secrete some signal molecules, which are as chemotactic factors to attract each other and mat
Site of ● Extracellular ligand cell-cell ontact Activation of enzyme activity Change in cytoskeletal organizatie skeleton Change in ion erme Activation of DNA synthe Activation of RNA synthe Extracellular matrix Figure 15. 1 An overview of some of the ways that intracellu- loreinnale mav he initiated and the types of responses that can
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