Presentation on theme: "Cellular Communication Chapter 11 Local communication In what ways do cells communicate locally? In what ways do cells communicate over longer distances?In."— Presentation transcript:
Cellular Communication Chapter 11
Local communication In what ways do cells communicate locally? In what ways do cells communicate over longer distances?In what ways do cells communicate over longer distances?
Regulation by chemical messengers axon endocrine gland receptor proteins target cell Neurotransmitters released by neurons Hormones release by endocrine glands receptor proteins hormone carried by blood neurotransmitter Lock & Key system
Three Stages of Cell Signaling Reception 1 EXTRACELLULARFLUID Receptor Signalingmolecule Plasma membrane CYTOPLASM 1
Fig Reception 1 EXTRACELLULARFLUID Receptor Signalingmolecule Plasma membrane CYTOPLASM 1 Relay molecules in a signal transduction pathway Transduction 2
Fig EXTRACELLULARFLUID Plasma membrane CYTOPLASM Receptor Signalingmolecule Relay molecules in a signal transduction pathway Activation of cellular response Reception TransductionResponse 1 2 3
Steroid Hormones: Hormone(testosterone) Receptorprotein Plasmamembrane EXTRACELLULARFLUID DNA NUCLEUS CYTOPLASM What type of Molecule is a steroid?
Receptorprotein Hormone(testosterone) EXTRACELLULARFLUID Plasmamembrane Hormone-receptorcomplex DNA NUCLEUS CYTOPLASM
Hormone(testosterone)EXTRACELLULARFLUID Receptorprotein Plasmamembrane Hormone-receptorcomplex DNA NUCLEUS CYTOPLASM
Hormone(testosterone) EXTRACELLULARFLUID Plasmamembrane Receptorprotein Hormone-receptorcomplex DNA mRNA NUCLEUS CYTOPLASM
Hormone(testosterone) EXTRACELLULARFLUID Receptorprotein Plasmamembrane Hormone-receptorcomplex DNA mRNA NUCLEUS New protein CYTOPLASM
Peptide Hormones Nuerotransmitters How will the structure of these molecules cause cause them to target a cell differently?
Action of protein hormones activates enzyme activates enzyme activates enzyme ATP produces an action P cytoplasm receptor protein response reception secondary messenger system signal-transduction pathway acts as 2° messenger target cell plasma membrane binds to receptor protein protein hormone ATP activates cytoplasmic signal cAM P GTP activates G-protein transduction
adrenal gland Ex: Action of epinephrine (adrenaline) activates protein kinase-A activates glycogen phosphorylase activates adenylyl cyclase epinephrine liver cell released to blood receptor protein in cell membrane cytoplasm 6 glycogen activates phosphorylase kinase GTP cAMP 4 activates G protein ATP glucose activates GTP 3 signal transduction response 7 GDP
Ion Channel Receptors Signalingmolecule(ligand) Gateclosed Ions Ligand-gated ion channel receptor Plasmamembrane Gate open Cellularresponse Gate closed Seen with neurotransmitters neurotransmitters
Signaling molecule Receptor Activated relay molecule Inactive protein kinase 1 Activeproteinkinase1 Inactive 2 ATP ADP Activeproteinkinase2 P P PP Inactive 3 ATP ADP Activeproteinkinase3 P P PP i ATP ADP P Activeprotein PP P i Inactiveprotein Cellularresponse Phosphorylation cascade i
First messenger Fig G protein Adenylylcyclase GTP ATP cAMP Secondmessenger Protein kinase A G protein-coupled receptor Cellular responses
Benefits of a 2° messenger system Amplification! signal receptor protein Activated adenylyl cyclase amplification GTPG protein product enzyme protein kinase cAMP Not yet activated FAST response! amplification Cascade multiplier!
EXTRA-CELLULARFLUID Signaling molecule (first messenger) G protein GTP G protein-coupled receptor Phospholipase C PIP 2 IP 3 DAG (second messenger) IP 3 -gated calcium channel Endoplasmic reticulum (ER) Ca 2+ CYTOSOL
G protein EXTRA-CELLULARFLUID Signaling molecule (first messenger) G protein-coupled receptor Phospholipase C PIP 2 DAG IP 3 (second messenger) IP 3 -gated calcium channel Endoplasmic reticulum (ER) Ca 2+ CYTOSOL (second messenger) GTP
Fig G protein EXTRA-CELLULARFLUID Signaling molecule (first messenger) G protein-coupled receptor Phospholipase C PIP 2 DAG IP 3 (second messenger) IP 3 -gated calcium channel Endoplasmic reticulum (ER) Ca 2+ CYTOSOL Variousproteinsactivated Cellularresponses (secondmessenger) GTP
Fig Growth factor Receptor Phosphorylationcascade Reception Transduction Activetranscriptionfactor Response P Inactivetranscriptionfactor CYTOPLASM DNA NUCLEUS mRNA Gene
Fig Reception Transduction Response Binding of epinephrine to G protein-coupled receptor (1 molecule) Inactive G protein Active G protein (10 2 molecules) Inactive adenylyl cyclase Active adenylyl cyclase (10 2 ) ATP Cyclic AMP (10 4 ) Inactive protein kinase A Active protein kinase A (10 4 ) Inactive phosphorylase kinase Active phosphorylase kinase (10 5 ) Inactive glycogen phosphorylase Active glycogen phosphorylase (10 6 ) Glycogen Glucose-1-phosphate (10 8 molecules)
Homology in hormones prolactin mammals milk production birds fat metabolism amphibians metamorphosis & maturation fish salt & water balance growth & development What does this tell you about these hormones? growth hormone same gene family gene duplication? How could these hormones have different effects?
How can 1 signal molecule have multiple responses?
Let’s go to the Let’s go to the Video!
Apoptosis Cell signaling example
Fig a Ced-9 protein (active) inhibits Ced-4 activity Mitochondrion Ced-4Ced-3 Receptor for death- signalingmolecule Inactive proteins (a) No death signal
Fig b (b) Death signal Death-signalingmolecule Ced-9(inactive) Cellformsblebs ActiveCed-4ActiveCed-3 Activationcascade Otherproteases Nucleases