BC basic - from big bang

1
Phosphorylation
Fischer, Kreb (1978)
Ser Thr Tyr (His)
Kinase phosphorylation
Conformational Change
dephosphorylastion Phosphatase
Glycogen phosphorylase b
Glycogen phosphorylase a
Inactive
Active
Juang RH (2004) BCbasics
2
Regulation of Blood Sugar
Cori Cori (1947)
Signal Transduction
Decreased
Insulin
High blood sugar
Glycogen synthase
Liver
Pancreas
Hormone
Glycogen
Blood
Glucose
Glucagon
Low blood sugar
Juang RH (2004) BCbasics
3
Rapid Response to Blood Sugar Concentration
Glycogen phosphorylase
Glycogen synthase
Enzyme activity
Glucose
Not controlled in gene level
Very rapidly ?
Adapted from Stryer (1995) Biochemistry (4e) p.597
4
Glycogen Phosphorylase, GP
Glc-1-P ? Glc-6-P ? Glycolysis
Glycogen
n
n-1
Glycogen phosphorylase a
Phosphorylase

GP kinase
6.2
6.4

Glycogen phosphorylase b (inactive)
6.3
Juang RH (2004) BCbasics
5
cAMP Controls Protein Kinase A Activity
A
Active kinase
A
cAMP
A
A
Nucleus
CREB
Alberts et al (2002) Molecular Biology of the
Cell (4e) p. 857, 858
Activation
Gene expression
CREB
DNA
6
cAMP Is the Second Messenger
Sutherland (1971)
Receptor
Adenylate cyclase
Cyclase
G protein
G protein
GP kinase
Inactive
GP
Juang RH (2004) BCbasics
Active
7
Receptors on Cell Membrane
Gilman, Rodbell (1994)
Glucagon
Adenylate cyclase
-GDP GTP
Glycogen breadkdown
A
The third group Ion-channel-linked Receptor
Insulin
a
b
kinase
active
Juang RH (2004) BCbasics
Glycogen Synthase
8
Glucagon
PKA
A
active
inactive
Adapted from Kleinsmith Kish (1995) Principles
of Cell and Molecular Biology (2e) p.217
9
Signal Transduction
?????
Hormone Signal
Receptor
?????
??? G-protein
??????
??????
????
Juang RH (2004) BCbasics