Summary - MBBs

MECHANISMS OF HORMONE
ACTION


1)ADENYLYL CYCLASE -CYCLIC AMP
SYSTEM
 Formation of HR complex
 Activation of G protein
 Activation of adenylyl cyclase
 ATP to cyclic GMP
 Activation of Protein Kinase A
 Phosphorylation of serine and
threonine residues of cellular
enzymes


Effect of Protein Kinase on gene
regulation
 PKA
 Nucleus
 Phosphorylation of Camp response
element binding protein(CREB)
 Transcription
 Alter genetic function

, 2)MEMBRANE PHOSPHOLIPD –
PHOSPHOLIPASE SYSTEM
 HR complex
 Activation of G protein
 Activation of phospholipase C
 Cleavage of membrane
phosphatidylinositol
 Production of inositol triphosphate
and diacyl glycerol


IP3 SYSTEM
 Binding of IP3 with receptors on ER
 Calcium binding with Calcium
Binding Protein (CaBP)
 Activation of protein kinase
 CaBP alter cell functions


DAG SUBSYSTEM
 DAG activates Protein Kinase C
 Phosphorylation of intracellular
proteins