Essential Cell Biology 5th edition

Contents
xxvii
CHAPTER 16
Cell Signaling 533
GENERAL PRINCIPLES OF CELL SIGNALING 534
Signals Can Act over a Long or Short Range 534
A Limited Set of Extracellular Signals Can Produce a Huge Variety of Cell Behaviors 537
A Cell’s Response to a Signal Can Be Fast or Slow 538
Cell-Surface Receptors Relay Extracellular Signals via Intracellular Signaling Pathways 539
Some Intracellular Signaling Proteins Act as Molecular Switches 541
Cell-Surface Receptors Fall into Three Main Classes 543
Ion-Channel-Coupled Receptors Convert Chemical Signals into Electrical Ones 544
G-PROTEIN-COUPLED RECEPTORS 545
Stimulation of GPCRs Activates G-Protein Subunits 545
Some Bacterial Toxins Cause Disease by Altering the Activity of G Proteins 547
Some G Proteins Directly Regulate Ion Channels 548
Many G Proteins Activate Membrane-bound Enzymes That Produce Small
Messenger Molecules 549
The Cyclic AMP Signaling Pathway Can Activate Enzymes and Turn On Genes 549
The Inositol Phospholipid Pathway Triggers a Rise in Intracellular Ca 2+ 552
A Ca 2+ Signal Triggers Many Biological Processes 553
A GPCR Signaling Pathway Generates a Dissolved Gas That Carries a Signal to Adjacent Cells 554
GPCR-Triggered Intracellular Signaling Cascades Can Achieve Astonishing Speed,
Sensitivity, and Adaptability 555
ENZYME-COUPLED RECEPTORS 557
Activated RTKs Recruit a Complex of Intracellular Signaling Proteins 558
Most RTKs Activate the Monomeric GTPase Ras 559
RTKs Activate PI 3-Kinase to Produce Lipid Docking Sites in the Plasma Membrane 560
Some Receptors Activate a Fast Track to the Nucleus 565
Some Extracellular Signal Molecules Cross the Plasma Membrane and Bind to Intracellular Receptors 565
Plants Make Use of Receptors and Signaling Strategies That Differ from Those Used by Animals 567
Protein Kinase Networks Integrate Information to Control Complex Cell Behaviors 567
ESSENTIAL CONCEPTS 569
QUESTIONS 571