Chapter8 Cell signaling o Cell signaling can affect virtually every aspect of cell structure and function t Activation of enzyme activity t Change in cytoskeletal organization t Change in ion permeability t Initiation of DNA synthesis t Activation or repression of gene expression Importance of Signal Transduction Development Apoptosis Transduction Cell Growth Immunology Metabolism
❖Cell signaling can affect virtually every aspect of cell structure and function: Activation of enzyme activity; Change in cytoskeletal organization; Change in ion permeability; Initiation of DNA synthesis; Activation or repression of gene expression. Chapter 8 Cell Signaling
1. Overview of intercellular signaling (c) Autocrine signaling (a) Endocrine signaling Key: Blood vessel o Extracellular signal Receptor ⊙ 9 Membrane-attached Hormone secretion signal into blood by endocrine gland Distant target cells Target sites on same cell (b)Paracrine signaling (d)Signaling by plasma membrane-attached proteins ⑧ Secretory cell Adjacent target cell Signaling cell Adjacent target cell General schemes of intercellular signaling
1. Overview of intercellular signaling General schemes of intercellular signaling
A. Some of the basic characteristics of cell signaling (1)Each cell is programmed to respond to specific combinations of extracellular signal molecules The cell integrates differentinformation and mounts an appropriate and comprehensive response. ☆ These signal molecules work in combinations to DIVIDE regulate the behavior of the cell E DIFFERENTIATE ☆ Cells respond to stimuli via cell signaling
(1) Each cell is programmed to respond to specific combinations of extracellular signal molecules The cell integrates different information and mounts an appropriate and comprehensive response. ❖These signal molecules work in combinations to regulate the behavior of the cell. ❖Cells respond to stimuli via cell signaling A. Some of the basic characteristics of cell signaling
Signal integration (A) (B) B B TP ATP ATP ATP ADP ADP DP ADP PrY e DOWNSTREAM SIGNALS DOWNSTREAM SIGNALS
(2) Signaling pathways consist of a series of steps Recognition of the EXTRACELLULAR SIGNAL MOLECULE stimulus by a specific RECEPTOR PROTEIN plasma membrane receptor 2. Transfer of a signal across the plasma membrane INTRACELLULAR SIGNALING PROTEINS3. Signal magnification: signal magnification Transmission of the signal to effector molecules within the cell, which causes a change in cellular TARGET PROTEINS activities metabolic gene regulatory cytoskeletal enzyme protein 4. Cessation of the cellular altered altered gene altered ce response due to metabolism expression shape or movement inactivation of the signal molecule
(2) Signaling pathways consist of a series of steps signal magnification 1. Recognition of the stimulus by a specific plasma membrane receptor. 2. Transfer of a signal across the plasma membrane. 3. Signal magnification: Transmission of the signal to effector molecules within the cell, which causes a change in cellular activities. 4. Cessation of the cellular response due to inactivation of the signal molecule