Components of Signal Transduction Flashcards
What are the components of signal transduction?
- Ligands
- Receptors
- Second Messengers
What are Ligands?
Signaling molecules that bind to receptors and initiate cellular responses.
They vary in size, shape and origin.
What are the types of ligands?
- Hormones: Insulin, cortisol, glucagon, estrogen.
- Neurotransmitters: Acetylcholine, dopamine.
- Cytokines: Interleukins, interferons.
- Growth factors: EGF, VEGF.
What are the types of receptors?
- Cell surface receptors.
- Intracellular receptors
What are the cell surface receptors?
- G-protein coupled receptors.
- Receptor Tyrosine Kinases.
- Ion Channel receptors.
What is the structure of GPCR?
7 transmembrane domains.
What is the function of GPCR?
Activates G-proteins to modulate 2nd messengers.
What is an example of GPCR?
B2-Adrenergic Receptor.
What is the structure of RTK?
1 transmembrane domain with intracellular kinase activity.
What is the functions of RTK?
Activates pathways like MAPK & PI3K-AKT.
What is an example of RTK?
Insulin Receptor.
What is the function of Ion Channel receptors?
They regulate the ion flow upon ligand binding.
What is an example of Ion channel receptors?
Nicotinic acetylcholine receptor
What is the location of intracellular receptors?
Nucleus or cytoplasm which means it has direct binding to DNA.
What is the function of intracellular receptors?
Bind lipophilic ligands to regulate gene expression.
What is an example of intracellular receptors?
Glucocorticoid receptor.
What is the function of 2nd messengers?
Propagate and amplify intracellular signals.
What is the physiological role of cAMP?
Glycogen breakdown, heart rate regulation.
What is the physiological role of cGMP?
Smooth muscle relaxation, phototransduction.
What is the physiological role of calcium ions?
Muscle contraction, neurotransmitter release.
What is the physiological role of IP3?
Calcium release from ER.
What is the physiological role of DAG?
Cell proliferation, immune responses.
What is the physiological role of Nitric Oxide?
Vasodilation, neurotransmission.
What is the ligand for GPCR pathway?
Adrenaline.
What are the ligands for RTK pathway?
Insulin & EGF.
What is the ligand for JAK-STAT pathway?
Interleukin-6.
What is the ligand for PI3-AKT pathway?
Insulin.
What is the ligand for calcium signaling?
Acetylcholine.
