Section 7 Flashcards
How do hydrophobic and hydrophilic cell signals differ?
Hydrophobic: works on intracellular receptors, carried thru blood
Hydrophillic: works on cell surface (plasma membrane)
How are both hydrophobic and hydrophilic cell signals alike?
Induce gene transcription and cell signal must eventually terminate (transient); final destination is at the nucleus
What is an endocrine signal?
Signal is carried via blood
What is a paracrine signal?
Signal is sent from one cell to an adjacent cell
What is an autocrine signal?
Signals itself
What are the three major kinase receptors?
- Tyrosine-kinase
- JAK-STAT
- Serine-Threonine kinase
What are the features of tyrosine-kinase receptors?
- Majority of growth factor receptors
- Needs ATP
- Dimerization
- Activates proteins kinase
What site do 50% of drugs target?
G-Protein Coupled Heptahelical Receptor
What activates G-Protein couple heptahelical receptor?
cAMP, IP3, DAG
What is the third messenger in G-Protein Coupled Heptahelical Receptor?
Calcium
What are the actions of G-Protein?
- Bind GDP in inactive state, GTP in active state
- Activate/Inhibit adenylate cyclase
- Contain GTPase activity
How does G-Protein get terminated?
- Degrade cAMP to AMP
- Trade GTP for GDP
- Internalize receptor
- Remove phosphate (phosphatases)
What is the phosphate donor in the plasma membrane receptors?
ATP
What is the phosphate acceptor in the plasma membrane receptors?
Tyrosine, Serine, Theronine (all have -OH groups)
What is the target of IP3?
Calcium channel