What are the four components to all signals?
- 1. Ligand Biochemistry and Mode of Delivery
- 2. Receptor
- 3. Second Messenger Cascade
- 4. Target Mechanisms
What are the sources of solubilized molecules?
- A. Paracrine signaling- local, short distance, intercellular
- B. Endocrine signaling- systemic, long distance, intercellular
- C. Synaptic signaling- paracrine? endocrine?both?
- D. Exchange of cytosolic components
- E. Juxacrine Signaling
What does synaptic signaling do?
- 1. Adaptation for systemic regulation in Animalia
- 2. Nerves can act long-range like endocrine system
- 3. Synapse is shortest paracrine delivery of all and, thus, can affect as few as a single cell
- 4. Cool electrical control of signal release
What are the transmembrane proteins?
- A. Integrin, cadherin, delta, notch, eph,ephrin
- B. G-protein-linked receptors
- C. Enzyme-linked receptors
- D. Specialized growth factors receptors
- E. Ion channel-linked receptors
What are the Intracellular Receptors?
- A. Nuclear receptors- transcriptional activators
- 1. steroid hormone receptors, vitamin-D receptors
- 2. thyroid hormone receptors
- 3. retinoic acid receptors
- 4. orphan receptors
- B. Soluble gas receptors- NO,CO
Trimeric G-protein structure and function
- 1. Three protein subunits (different genes)- α,β,γ
- 2. Electrostatically bound to receptor as inactive trimeric form: α-subunit has GDP bound
- 3. Activation and Inactivation regulate downstream activity