Receptors: Understanding Types and Functions
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The document provides an overview of receptors, defined as macromolecules that recognize signal molecules and initiate cellular responses. It discusses various types of receptors, including ligand-gated ion channels, G protein-coupled receptors (GPCRs), enzyme-linked receptors, and intracellular receptors, along with their specific functions and examples. Additionally, the document emphasizes the mechanisms of signal transduction and the physiological effects of these receptors on different organs.
![TYPES OF RECEPTORS
Ligand Gated ion Channel Receptor Examples
G Protein coupled receptors
Kinase linked receptors
Intracellular receptors
Examples of GPCRs
Muscarinic receptors [M1-M5]
Adrenergic receptors [α and β]
Histamine receptors [H1-H3]
Dopamine receptors [D1-D5]
Opioid receptors [μ κ б]
5-HT receptors 5-HT[1-7] except 5-
HT3
GABAb receptors
*GPCR superfamily-largest and
most diverse group of proteins
*seven-transmembrane,
serpentine, G protein–linked
receptors
Transmembrane JAK-STAT binding
receptors
Gs : Adenylyl cyclase , Ca2+
channel
Gi : Adenylyl cyclase, K+
channel opening
Go : Ca2+ channel
inhibition
Gq : Phospholipase C](https://image.slidesharecdn.com/receptorsonlyppt-240724095140-35a66fe2/85/Receptors-Understanding-Types-and-Functions-8-320.jpg)
![TYPES OF RECEPTORS
Ligand Gated ion Channel Receptor Examples
G Protein coupled receptors
Kinase linked receptors
Intracellular receptors
Examples of GPCRs
Muscarinic receptors [M1-M5]
Adrenergic receptors [α and β]
Histamine receptors [H1-H3]
Dopamine receptors [D1-D5]
Opioid receptors [μ κ б]
5-HT receptors 5-HT[1-7] except 5- HT3
GABAb receptors
Transmembrane JAK-STAT binding
receptors
Gs : Adenylyl cyclase , Ca2+
channel
Gi : Adenylyl cyclase, K+
channel opening
Go : Ca2+ channel
inhibition
Gq : Phospholipase C](https://image.slidesharecdn.com/receptorsonlyppt-240724095140-35a66fe2/85/Receptors-Understanding-Types-and-Functions-9-320.jpg)
Receptors: Understanding Types and Functions
- 1. RECEPTORS Dr. BK Shoraisham JR Dept of Pharmacology
- 2. RECEPTORS It is defined as a macromolecule or binding site located on the surface or inside the effector cell that serves to recognize the signal molecule/drug and initiate the response to it, but itself has no other function. Two essential functions, viz, recognition of the specific ligand molecule and transduction of the signal into a response. Receptor molecule has a ligand binding domain and an effector domain (functional conformational change)
- 3. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Enzyme linked receptors G Protein coupled receptors Intracellular receptors Transmembrane JAK-STAT binding receptors
- 4. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor G Protein coupled receptors Enzyme linked receptors Intracellular receptors Transmembrane JAK-STAT binding receptors
- 5. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor G Protein coupled receptors Nicotinic receptors 5-HT3 receptors GABAa receptors NMDA receptors Enzyme linked receptors Intracellular receptors EXAMPLES Transmembrane JAK-STAT binding receptors
- 6. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor G Protein coupled receptors Enzyme linked receptors Intracellular receptors Nicotinic receptors 5-HT3 receptors GABAa receptors NMDA receptors EXAMPLES 5HT (Serotonin) 5HT3 (CTZ) Na+ Influx Vomiting Acetylcholine Nm (Skeletal Muscle) Na+ Influx Muscle Contraction Transmembrane JAK-STAT binding receptors
- 7. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor G Protein coupled receptors Enzyme linked receptors Intracellular receptors Nicotinic receptors 5-HT3 receptors GABAa receptors NMDA receptors EXAMPLES 5HT (Serotonin) 5HT3 (CTZ) Na+ Influx Vomiting Acetylcholine Nm (Skeletal Muscle) Na+ Influx Muscle Contraction Transmembrane JAK-STAT binding receptors
- 8. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors Examples of GPCRs Muscarinic receptors [M1-M5] Adrenergic receptors [α and β] Histamine receptors [H1-H3] Dopamine receptors [D1-D5] Opioid receptors [μ κ б] 5-HT receptors 5-HT[1-7] except 5- HT3 GABAb receptors *GPCR superfamily-largest and most diverse group of proteins *seven-transmembrane, serpentine, G protein–linked receptors Transmembrane JAK-STAT binding receptors Gs : Adenylyl cyclase , Ca2+ channel Gi : Adenylyl cyclase, K+ channel opening Go : Ca2+ channel inhibition Gq : Phospholipase C
- 9. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors Examples of GPCRs Muscarinic receptors [M1-M5] Adrenergic receptors [α and β] Histamine receptors [H1-H3] Dopamine receptors [D1-D5] Opioid receptors [μ κ б] 5-HT receptors 5-HT[1-7] except 5- HT3 GABAb receptors Transmembrane JAK-STAT binding receptors Gs : Adenylyl cyclase , Ca2+ channel Gi : Adenylyl cyclase, K+ channel opening Go : Ca2+ channel inhibition Gq : Phospholipase C
- 10. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors Adenyl cyclase- cAMP Phospholipase-C: IP3-DAG Ion Channels Three effector systems Transmembrane JAK-STAT binding receptors
- 11. G Protein coupled receptors Adenyl cyclase- cAMP Ion Channels Phospholipase-C: IP3-DAG
- 12. G Protein coupled receptors Effects of cAMP on Organs Ion Channels Phospholipase- C: IP3-DAG PKA phosphorylates many functional proteins including troponin and phospholamban, they interact with Ca2+ and also Calcium is made available by entry from outside (direct activation of myocardial membrane Ca2+ channels by Gsα and through their phosphorylation by PKA) as well as from intracellular stores. Increases force of contraction, Increase Heart rate, Increases Blood pressure.
- 13. G Protein coupled receptors Effects of cAMP on Organs Ion Channels Phospholipase- C: IP3-DAG PKA then phosphorylates a number of enzymes involved in lipolysis, including hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). HSL and ATGL are responsible for hydrolyzing triglycerides into free fatty acids and glycerol causing
- 14. G Protein coupled receptors Effects of cAMP on Organs Ion Channels Phospholipase- C: IP3-DAG The effects of cAMP on liver glycogenolysis Activates glycogen phosphorylase Inhibits glycogen synthase: cAMP inhibits
- 15. G Protein coupled receptors Effects of cAMP on Organs Ion Channels Phospholipase- C: IP3-DAG cAMP has a relaxing effect on smooth muscle -Increasing the activity of the calcium pump removing calcium from the cytoplasm -Activating MLCP, which dephosphorylates MLCK. MLCK is an enzyme that phosphorylates myosin light chain, which is required for smooth muscle contraction -Inhibiting the release of calcium from the SR -Opening potassium channels, causing hyperpolarization and relaxation
- 16. Adenyl cyclase- cAMP Phospholipase-C: IP3-DAG Ion Channels G Protein coupled receptors
- 17. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C: IP3-DAG Effects on Organs Ion Channels -The PLC, IP3, and DAG pathway is involved in the release of neurotransmitters from presynaptic terminals. -DAG can activate PKC, which can then phosphorylate and activate presynaptic proteins that are involved in vesicle release. CNS Stimulation
- 18. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C: IP3-DAG Effects on Organs Ion Channels Smooth muscle contraction •Vasoconstriction •Bronchoconstriction •Increased gastrointestinal motility •Increased bladder contraction •Mydriasis
- 19. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C: IP3-DAG Effects on Organs Ion Channels Increases force of contraction Increase Heart rate Increases Blood pressure
- 20. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C: IP3-DAG Effects on Organs Ion Channels In the pituitary gland, the PLC/IP3/DAG pathway is activation leads to the release of growth hormone and thyrotropin, respectively. In the pancreas, the PLC/IP3/DAG pathway is activated by cholecystokinin (CCK). This leads to the release of insulin.
- 21. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C- inositol phosphate Ion Channels
- 22. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C- inositol phosphate Ion Channels Regulation K+ opening Adrenergic- α2 Muscarinic- M2 Dopamine-D2 5-HT1A GABAB Opioid-µ, δ Adenosine-A Ca2+ closing Dopamine-D2 GABAB Opioid-κ Adenosine-A1 Somatostatin Ca2+ opening Adrenergic- β1
- 23. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C- inositol phosphate Ion Channels Regulation K+ opening Adrenergic- α2 Muscarinic- M2 Dopamine-D2 5-HT1A GABAB Opioid-µ, δ Adenosine-A Ca2+ closing Dopamine-D2 GABAB Opioid-κ Adenosine-A1 Somatostatin Ca2+ opening Adrenergic- β1
- 24. G Protein coupled receptors Adenyl cyclase- cAMP Phospholipase-C- inositol phosphate Ion Channels Regulation K+ opening Adrenergic- α2 Muscarinic- M2 Dopamine-D2 5-HT1A GABAB Opioid-µ, δ Adenosine-A Ca2+ closing Dopamine-D2 GABAB Opioid-κ Adenosine-A1 Somatostatin Ca2+ opening Adrenergic- β1
- 25. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Enzyme linked receptors Intracellular receptors large extracellular ligand binding domain connected through a single transmembrane helical peptide chain to an intracellular subunit having enzymatic property Transmembrane JAK-STAT binding receptors
- 26. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Enzyme linked receptors Intracellular receptors Utilized primarily by peptide hormones Receptor tyrosine kinases (RTKs) are the largest family of enzyme- linked receptors --Insulin receptor, Epidermal growth factor receptor (EGFR), Fibroblast growth factor receptor (FGFR), Platelet-derived growth factor receptor (PDGFR) Serine/threonine-specific protein kinases--TGF-β receptor Guanylate cyclases --Atrial natriuretic peptide receptor (ANPR) --Brain natriuretic peptide receptor (BNPR) EXAMPLES Transmembrane JAK-STAT binding receptors
- 27. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors All steroidal hormones (glucocorticoids, mineralocorticoids, androgens, estrogens, progesterone) Thyroxine vit D and vit A Receptors Transmembrane JAK-STAT binding receptors
- 28. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors Transmembrane JAK-STAT binding receptors
- 29. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors Transmembrane JAK-STAT binding receptors Agonist-induced dimerization cytosolic tyrosine protein kinase JAK binds on intracellular domain JAK gets activated and phosphorylates tyrosine residues of the receptor ------------free moving protein STAT binds to the receptor which is also phosphorylated by JAK ----- ----------Pairs of phosphorylated STAT dimerize and translocate to the nucleus to regulate gene transcription resulting in a biological response
- 30. TYPES OF RECEPTORS Ligand Gated ion Channel Receptor Examples G Protein coupled receptors Kinase linked receptors Intracellular receptors Transmembrane JAK-STAT binding receptors Many cytokines growth hormone Prolactin interferons, etc. act through this type of receptor
Editor's Notes
- #12: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #13: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #14: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #15: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #16: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #17: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #18: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #19: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #20: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #21: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #22: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #23: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #24: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH
- #25: he cyclic AMP-dependent signaling pathway. G protein-coupled receptors (GPCRs) undergo conformational changes in response to various extracellular stimuli. Gsα subunit (G-proteins) exchanges GDP for GTP that activates adenylyl cyclase (AC), converting ATP to cAMP. Elevated cAMP levels, regulated by PDEs (also responsible for degradation of cGMP to GMP), then activate protein kinase A (PKA). PKA consists of a tetramer of two homo- or heterodimers regulatory subunits (R) and two catalytic subunits (C) responsible for the phosphorylation of several enzymes and transcription factors downstream [e.g., cAMP-response element-binding protein (CREB)]. The end product is gene expression to mediate cell growth and differentiation. Abbreviations: α, β, γ, Gs-protein subunits; AC, adenyl cyclase; C, catalytic subunit of protein kinase A; cAMP, cyclic AMP; CREB, cyclic AMP response element-binding protein, a transcription factor; GPCR, G-protein-coupled receptor; PDE, phosphodiesterase; PKA, protein kinase A; R, the regulatory subunits of protein kinase. Courtesy of Stratakis Lab, NICHD, NIH