Biology Reference
In-Depth Information
a
Antigen Presenting Cell
CD4
TCR/CD3
a
b
CD28
Cbp/PAG
d
d
g
g
γ
zz
AC
Gs
α
Lck
ATP
cAMP
Csk
R
Protein kinase A
(active)
Incomplete T cell activation
Antigen Presenting Cell
b
B7.1/B7.2
CD4
TCR/CD3
a
b
CD28
Cbp/PAG
d
PIP3
g
d
g
z
z
AC
Gs
α
Lck
p85
ATP
cAMP
p110
cAMP
5'-AMP
ZAP-70
PI3-K
ZAP-70
ZAP-70
Csk
Protein kinase A
(inactive)
IL-2 transcription, DNA replication
Full T cell activation
Fig. 2 PKA and PDE4 have opposing functions in proximal T-cell signaling. TCR ligation results
in rapid cAMP production in lipid rafts due to G protein coupling to raft-associated adenyl cyclase.
