diff --git a/2016-10-16-lecture09.md b/2016-10-16-lecture09.md index b468ef6..8cae6ff 100644 --- a/2016-10-16-lecture09.md +++ b/2016-10-16-lecture09.md @@ -25,25 +25,9 @@ What types of cell-cell communication underly signaling? The answer is familiar --- -## Endocrine signaling +## Synaptic, paracrine, and endocrine signaling -
- -Note: - ---- - -## Paracrine signaling - -
- -Note: - ---- - -## Signaling by membrane proteins - -
+
Neuroscience 5e Fig. 7.1
Note: @@ -61,7 +45,6 @@ Note: Note: - --- ## Signal amplification @@ -69,7 +52,8 @@ Note: * results in a tremendous increase in the potency of the initial signal * permits precise control of cell behavior -
+
Neuroscience 5e Fig. 7.2
+ Note: @@ -77,11 +61,16 @@ Note: ## Types of receptors +
+
+ * Ligand gated ion channels (channel linked receptors/ionotropic receptors)– e.g. nAChR, AMPA receptors * Enzyme linked receptors– typically have extracellular binding site for signals. Has intracellular domain with catalytic activity regulated by signal. Most are protein kinases that phosphorylate intracellular proteins. e.g. tyrosine kinase * G-protein coupled receptors– 7-transmembrane spanning receptors that signal through trimeric G-proteins intracellularly. The proteins can alter the function of many downstream proteins. e.g. muscarinic AChR, metabotropic glutamate receptors * Intracellular receptors– activated by cell permeant or lipophilic signaling molecules like steroid hormones. Signal binds directly to an intracellular protein which then activates transcription +
+ Note: @@ -90,9 +79,8 @@ Note: ## Categories of cellular receptors -Neuroscience 5e 7.4 +
Neuroscience 5e Fig. 7.4
-
Note: @@ -104,7 +92,8 @@ For enzyme linked receptors the signal binds extracellularly, which activates th ## Categories of cellular receptors -Neuroscience 5e 7.4 +
Neuroscience 5e Fig. 7.4
+ Note: @@ -122,7 +111,7 @@ For intracellular receptors, the signaling molecule passes through lipid membran * Two types of G-proteins: * Heterotrimeric G- proteins, composed of an α,β, γ subunits. Multiple members of each class. α subunit binds and hydrolyses GTP * Small G-proteins– monomeric GTPases (e.g. ras) -* Active when bound to GTP, inactive when bound to GDP. +* Active when bound to GTP, inactive when bound to GDP Note: @@ -148,12 +137,12 @@ Rate of GTP hydrolysis is important property of G-protein mediated signaling and ## Types of GTP-binding proteins -
+
Neuroscience 5e Fig. 7.5
+ Note: - --- ## Trimeric G-protein signaling @@ -164,7 +153,8 @@ Note: * Dissociates complex and activates * α and βγ subunits -
+
Molecular Biology of the Cell 4e Fig. 15.28
+ Note: @@ -190,11 +180,11 @@ Effector enzymes for activated G-proteins include adenylyl cyclase, guanylyl cyc ## Effector pathways associated with G-protein coupled receptors -
+
Neuroscience 5e Fig. 7.6
+ Note: - There are many types of alpha, beta, and gamma g-protein subunits allowing a specific and diverse range of downstream responses. This shows three examples of different heterotrimeric g proteins bound to 3 types of receptors with 3 different cellular responses. @@ -221,7 +211,8 @@ One target of calcium is calmodulin, a calcium binding protein abundant in the c ## Proteins involved in delivering and removing calcium to the cytoplasm -
+
Neuroscience 5e Fig. 7.7
+ Note: @@ -244,41 +235,37 @@ Another one intracellular releasing channel is the ryanodine receptor. These are ## Calcium activates calmodulin -
+
Molecular Biology of the Cell 4e Fig. 15.40
Note: - --- -## Title Text +## Calcium second messaging video summary -[http://courses.pbsci.ucsc.edu/mcdb/bio125/Animation07-02CalciumasaSecondMessenger.mov](http://courses.pbsci.ucsc.edu/mcdb/bio125/Animation07-02CalciumasaSecondMessenger.mov) - -
+
Neuroscience 5e Animation 7.2
Note: - --- ## Second messengers: cyclic nucleotides * cAMP and cGMP– derivatives of ATP and GTP. Made by adenylyl cyclase and guanylyl cyclase -* Bind to many targets– cAMP to protein kinase A; cGMP to protein kinase G +* Bind to many targets– cAMP to protein kinase A, cGMP to protein kinase G * Phosphodiesterases cleave cAMP and cGMP to inactivate them Note: - --- ## cAMP formation and destruction -
+
Molecular Biology of the Cell 4e Fig. 15.31
+ Note: @@ -300,18 +287,20 @@ Note: ## Diacylglycerol and IP3 -
+
Molecular Biology of the Cell 4e Fig. 15.35
+ Note: -Phosphatidylinositol 4,5-bisphosphate: PIP2, +Phosphatidylinositol 4,5-bisphosphate: PIP2 --- ## Neuronal second messengers -
+
Neuroscience 5e Fig. 7.7
+ Note: @@ -322,36 +311,16 @@ This table summarizes neuronal second messengers, their sources, targets, and in ## Second messenger life cycles -cyclic nucleotides +
cyclic nucleotides
Neuroscience 5e Fig. 7.7
-lipid signals +
lipid signals
Neuroscience 5e Fig. 7.7
-Neuroscience 5e 7.7 - -
- -
Note: And this depicts the mechanisms involved in production and degradation or removal of cyclic nucleotides and DAG and IP3. ---- - -## Second messenger life cycles - -cyclic nucleotides - -lipid signals - -gas signals - -
- -Note: - - --- ## 2nd messengers target protein kinases and phosphatases @@ -377,7 +346,8 @@ Protein substrates of kinases and phosphataes include enzymes, neurotransmitter ## Regulation of cellular proteins by phosphorylation -
+
Neuroscience 5e Fig. 7.8
+ Note: @@ -399,19 +369,10 @@ Note: ## Mechanism of activation of protein kinases -binding of cAMP to regulatory +
binding of cAMP to regulatory subunits free up the catalytic subunits
Neuroscience 5e Fig. 7.9
+
binding of calmodulin opens up protein to activate catalytic domain
Neuroscience 5e Fig. 7.9
+
DAG causes PKC to change its localization which leads it to be active
Neuroscience 5e Fig. 7.9
-subunits free up the catalytic subunits - -binding of calmodulin opens up - -protein to activate catalytic domain - -DAG causes PKC to change its - -localization which leads it to be active - -
Note: @@ -421,12 +382,12 @@ Note: ## Protein kinase A activation -
+
Molecular Biology of the Cell 4e Fig. 15.32
+ Note: - --- ## Other kinases @@ -449,7 +410,7 @@ Mitogen activated protein kinases (MAP kinases) ## MAP kinase cascade -
+
Molecular Biology of the Cell 4e Fig. 15-56
Note: @@ -474,7 +435,7 @@ CREB is an important nuclear signal ## Steps involved in transcription of DNA to RNA -
+
Neuroscience 5e Fig. 7.10
Note: @@ -485,10 +446,8 @@ uas: upstream activator sequence >upstream activating sequence or upstream activation sequence (UAS) is a cis-acting regulatory sequence. It is distinct from the promoter and increases the expression of a neighbouring gene. -upstream from minimal promoter TATA box, binding site for transactivators - -a cis acting regulatory sequence (like IRES) - --- ## CREB @@ -503,54 +462,27 @@ Note: ## Transcriptional regulation by CREB -
+
Neuroscience 5e Fig. 7.11
+ Note: --- -## Title Text +## Chemical signaling mechanisms video summary -[http://courses.pbsci.ucsc.edu/mcdb/bio125/Animation07-01ChemicalSignalingMechanismsandAmplification.mov](http://courses.pbsci.ucsc.edu/mcdb/bio125/Animation07-01ChemicalSignalingMechanismsandAmplification.mov) - -
+
Neuroscience 5e Animation 5.2
Note: ---- - -## Nurturing defects in CREB mutant mice - -WT - -mutant - -
- -Note: - - ---- - -## How does NGF promote axon outgrowth - --NGF - -+NGF - -
- -Note: - - - --- ## Mechanism of action of NGF -
+
Neuroscience 5e Fig. 7.12
+ Note: @@ -561,12 +493,18 @@ nerve growth factor, binds to tyrosine kinase receptor (TrkA) leading to… ## Signaling at cerebellar parallel fiber synapses +
+
+ * Glutamate released from presynaptic cell binds ionotropic and metabotropic glutamate receptors * AMPA receptor opens and excites cell * mGluR receptor activates a signal transduction pathway that feeds back and decreases AMPA receptor activity * Called long term depression because now the same stimulus will lead to less depolarization than before (weakened synapse) -
+
+ +
Neuroscience 5e Fig. 7.13
+ Note: @@ -586,6 +524,9 @@ likely from phosphorylation of AMPA receptors by PKC and their elimination from ## Regulation of tyrosine hydroxylase by protein phosphorylation +
+
+ * AP invades axon terminal * Voltage-gated Ca²⁺ channels open * Intracellular Ca²⁺ does two things: @@ -597,7 +538,10 @@ likely from phosphorylation of AMPA receptors by PKC and their elimination from * Increase in transmitter release * Increase in post-synaptic response -
+
+ +
Neuroscience 5e Fig. 7.14
+ Note: