Lecture 8

Question 1

Nuclear Receptor Superfamily

Answer 1

• N terminal transcription activating domain activates transcription of target genes
• DNA Binding domain binds promoters of specific target genes
• C terminal ligand binding binds to small hydrophobic signaling molecule
• Both receptor and effector

Question 2

GPCR

Answer 2

• Half of pharmaceuticals target these pathways
• Activated by small molecules
• 7 transmembrane domain, 3 subunit
• Activated GPCR acts as GEF to exchange GDP for GTP on Galpha subunit -> dissociate from Gbeta/gamma
• Gs activate adenyl cyclase -> release cAMP -> activate PKA -> phosphorylate and activate CREB
• Golf use cAMP to trigger action potential
• Gq activate phospholipase C -> cleave PI(4,5)P2 to produce DAG and IP3 -> activate PKC and open Ca++ channels