Chapter 15 Signal Transduction
1) Endocrine, paracrine, autocrine signaling, and cell-cell speak to (Fig. 15-2).
Endocrine signaling can be long distance signaling. The would be pancreatic cells secreting insulin. Paracrine signaling is for close closeness. An example would be a nerve cellular releasing neurotransmitters. In autocrine signaling the cell that produces the ligand also contains the receptor for that ligand. This is how cancer cells operate. In signaling by plasma membrane attached proteins, the target cell does something in response to direct contact from your signaling cellular.
2) List examples of 1) steroid bodily hormones and 2) amino acid derivatives that become ligands.
What are the catecholamines, and which amino acid could they be derived from?
Anabolic steroid hormones bind cytosolic pain. They include cortisol, progesterone, estradiol, testo-sterone, thyroxine and retinoic acid solution. Steroid receptor complexes increase or cure the transcription prices of specific genes. Dopamine, norepinephrine, epinephrine, serotonin and histamine happen to be ligands which might be derived from amino acids. Catecholamines are ligands based on the valine tyrosine.
3) What's an agonist? What's a great antagonist? A physician prescribes isoproterenol to his patient -- why? Perhaps you should epinephrine? An additional patient gets alprenolol - why? (See page 629 and Fig. 15-5). Agonist= structural analog, antagonist=inhibitor. Isoproterenol has reduce Kd (higher affinity) than epinephrine, and can inc. easy heart muscle tissue contraction. Alprenol is an antagonist (" beta blockerвЂќ) and slows heart contractions
4) Precisely what are the five kinds of second messengers we all described in lecture. (Fig. 15-9 shows only four): cAMP, cGMP, DAG, IP3 and Ca2+
5) What are GTP-binding (switch) protein? When draught beer on? When are they off? (Fig 15-8). GEFs support turn all of them on. GAPs help convert them away. Are " onвЂќ when bind GTP, and " offвЂќ once bind GROSS DOMESTIC PRODUCT. Ex: Altura, Ran, trimeric G protein
6) What are kinases versus phosphatases? Kinases phosphorylate, Phosphatases dephosphorylate
7) Precisely what are the main popular features of a G-protein coupled radio (GPCR, Figs. 15-10, 15-12, and 15-13)? What is epinephrine and what kinds of receptors would it bind in what skin cells to induce what reactions?
GPCRs= " seven-passвЂќ pain with amino terminus outdoors cell and carboxy elance inside cell. Epinephrine produced when sugar needed quickly (inc. glycogenolysis and lipolysis); binds to GPCR receptor, which activates a G protein (switch protein), which activates an effector healthy proteins (adenylyl cyclase) producing cAMP NOTE: cAMP does not entail RTK (tyrosine), but uses Ser/Thr kinases! PDE degrades cAMP
8) Explain the three G proteins пЃЎ, пЃў, and пЃ§. What kind binds GTP/GDP (hint for question 6 above).
GО±вЂ”binds GDP, is connected to interior leaflet of plasma membrane, but dissociates from ОІ and Оі to activate effector proteins (adenylyl cyclase). GОІ and GОі hardly ever separated! Will be tethered to inner leaflet and are a unit.
9) Describe BE ANXIOUS (Fig. 15-14).
10) What is adenylyl cyclase? Figs 15-21 and 15-22. What does it do? How is adenylyl cyclase positively and adversely controlled? Positive: epinephrine binds ОІ adrenergic receptors to activate Gs, actvating adenylyl cyclase; Adverse: PGE binds to О± adrenergic pain to trigger Gi which in turn inhibits adenylyl cyclase.
11) The complete " Fight or perhaps Flight" road map. YIKES!! What goes on when cAMP rises? What are the results when cAMP drops?
12) T/F: Second messengers are long-lived in their signaling effectiveness? How is cAMP degraded? PDE
13) What is cAMP-dependent protein kinase and how does it work? (Figs. 15-23 and 16-31)
Do not involve tyrosine kinases (RTK), although use Ser/Thr kinases (binding of cAMP releases catalytic sitesвЂ¦)
14) What do we mean by amplification in transmission transduction? Fig. 15-26.
Numerous steps associated with signal transduction b/c you're amplifying signal at every step fast...