Page 290 - Color_Atlas_of_Physiology_5th_Ed._-_A._Despopoulos_2003

B. Diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP 3 ) as second messengers
e.g., PIP 2 (phosphatidylino- 5 P
epinephrine (α 1 ), Messenger binds sitol 4,5-bisphosphate) 4 P
histamine (H 1 ), to specific receptors P 1
CCK, etc.
Second
ECF messengers
IP 3 P 1 5 P
(inositol 1,4,5-
Cell G q trisphosphate) 4 P
membrane
PIP 2 DAG DAG
Phospho- (diacyl-
Cytosol 1 lipase C-β Phospho- glycerol)
lipase A2
Arachidonic acid Cellular Signal Transmission II
IP 3
2+
Ca stores
2 3 4
Protein
Eicosanoids
Protein
Calmodulin kinase C
Ca 2+ Ca 2+
Protein- P H + Plate 11.6
Na +
cGMP
pH
Cell response
Neurons, exocrine and endocrine pancreas,
platelets, liver, adrenal cortex, leukocytes, oocytes, etc.

C. Tyrosine kinase receptors
Messenger
Receptors Messenger-
for messenger EGF, etc. receptor e.g.,
ECF binding
Extracellular Insulin
domains α α
Trans-
Cell membrane membrane β β
alpha helix
Cytosol Cytosolic P P
domains
Tyrosine P P
kinase Phosphotyrosinyl residues
P P P P
1a Inactive monomers
Autophospho- P IRS-1
Tyr rylation
1b Active dimer SH2 domain
OH ATP ADP O
2– 2 Target proteins bind to 277
PO 3
SH2 domains
Despopoulos, Color Atlas of Physiology © 2003 Thieme
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