CST Guide:

02
Section I: Research Areas
Activation of MAPK
signaling with TPA
results in phosphorylation
of Erk1/2 at
Thr202/Tyr204.
Signaling
MAP Kinase Signaling
Mitogen-activated protein kinases (MAPKs) are a highly conserved family of serine/threonine protein
kinases involved in a variety of fundamental cellular processes such as proliferation, differentiation,
motility, stress response, apoptosis, and survival. Conventional MAPKs include the extracellular
signal-regulated kinase 1 and 2 (Erk1/2 or p44/42), the c-Jun N-terminal kinases 1-3 (JNK1-3)/
stress activated protein kinases (SAPK1A, 1B, 1C), the p38 isoforms (p38α, β, γ, and δ), and Erk5. The
lesser-studied, atypical MAPKs include Nemo-like kinase (NLK), Erk3/4, and Erk7/8.
A
B
C
kDa
80
60
50
40
30
80
60
50
40
30
293
NIH/3T3
C6
Phosphop44/42
MAPK
(Thr202/Tyr204)
+ – + – + –
p44/42
MAPK
λ phosphatase
– + – + – + TPA
Phospho-p44/42 MAPK (Erk1/2) (Thr202/Tyr204) (D13.14.4E) XP ® Rabbit mAb #4370: Confocal IF analysis of C2C12 cells, treated
with U0126 #9903 (10 μM for 1 hr) (A) or TPA #9905 (200 nM for 15 min) (B), using #4370 (green). Actin filaments were labeled with
Alexa Fluor ® 555 Phalloidin #8953 (red). Blue pseudocolor = DRAQ5 ® #4084 (fluorescent DNA dye). WB analysis of extracts from 293,
NIH/3T3, and C6 cells, treated with λ phosphatase or TPA #4174 as indicated (C), using #4370 (upper), or p44/42 MAPK (Erk1/2) (137F5)
Rabbit mAb #4695 (lower).
Signaling via the conventional MAPKs follows a classical
three-tiered kinase cascade: MAPKKK MAPKK MAPK.
CONVENTIONAL MAPKS
ATYPICAL MAPKS
A broad range of extracellular stimuli including mitogens, cytokines, growth factors, and environmental
stressors stimulate the activation of one or more MAPKK kinases (MAPKKKs) via receptor-dependent
and -independent mechanisms. MAPKKKs then phosphorylate and activate a downstream MAPK
kinase (MAPKK), which in turn phosphorylates and activates MAPKs. Activation of MAPKs leads to the
phosphorylation and activation of specific MAPK-activated protein kinases (MAPKAPKs), such as members
of the RSK, MSK, or MNK family, and MK2/3/5. These MAPKAPKs function to amplify the signal
and mediate the broad range of biological processes regulated by the different MAPKs. While most
MAPKKK, MAPKK, and MAPKs display a strong preference for one set of substrates, there is significant
cross-talk in a stimulus- and cell-type–dependent manner.
Activation of MAPK signaling by TPA results in
phosphorylation of c-Fos, a nuclear oncogene
that dimerizes with c-Jun to form the AP-1
transcription factor.
Phospho-c-Fos (Ser32) (D82C12) XP ® Rabbit mAb (PE Conjugate) #11919:
Flow cytometric analysis of HeLa cells, untreated (blue) or treated with TPA #4174
(green), using #11919.
Events
Phospho-c-Fos (Ser32) (PE Conjugate)
UV treatment activates the p38 MAPK signaling pathway, resulting
in phosphorylation of MKK3 at Ser189 and MKK6 at Ser207.
Phospho-MKK3 (Ser189)/MKK6
(Ser207) (D8E9) Rabbit mAb #12280:
Confocal IF analysis of HeLa cells,
untreated (left) or UV-treated (40 mJ/
cm 2 with 30 min recovery; right), using
#12280 (green). Actin filaments were
labeled with DY-554 phalloidin (red).
Blue pseudocolor = DRAQ5 ® #4084
(fluorescent DNA dye).
chapter 02: Signaling
Activation of MAPK
signaling with TPA
results in phosphorylation
of MEK1/2 at
Ser217/221.
kDa
140
100
80
60
50
40
30
100
80
60
50
40
HeLa
NIH/3T3
Phospho-
MEK1/2
(Ser217/221)
MEK1/2
+ – + – TPA
Phospho-MEK1/2 (Ser217/221)
(41G9) Rabbit mAb #9154: WB
analysis of extracts from untreated or
TPA-treated HeLa and NIH/3T3 cells
using #9154 (upper) or MEK1/2 Antibody
#9122 (lower).
Phopho-p38 MAPK
(Thr180/Tyr182) is
expressed in human
colon carcinoma.
Stimulus
Growth Factors,
Mitogens, GPCR,
Antigen Receptors
Stress, DNA Damage, GPCR,
Inflammatory Cytokines,
Growth Factors
Stress, Mitogens, GPCR,
Neurotrophic Factors,
GPCR, RTKs,
Neurotrophic Factors
Activator
MAPKKK
MAPKK
RAS
A-Raf,
B-Raf, c-Raf,
Mos, Tpl2
MEK1/2
Ras, Rho, Rac,
Cdc42, TRAFs,
GADD45a
MEKK3/4,
ASK1/2, TAOK1/2,
MLK3, Tpl2,
DLK, ZAK
MKK3/6,
MKK4
Ras, Rho, Rac,
Cdc42, TRAFs,
GADD45a
MEKK1/2/4,
MLK1-4, ASK1/2,
TAOK1/2,TAK1,
DLK, ZAK
Gαq, Gα12/13,
Ras, Rap
MEKK2/3
MKK4/7 MEK5 PAK1/2/3
Unknown
Anisomycin treatment results in activation and nuclear
translocation of phospho-SAPK/JNK (Thr183/Tyr185).
Phospho-SAPK/JNK (Thr183/Tyr185)
(G9) Mouse mAb #9255: Confocal IF
analysis of HeLa cells, untreated (left)
and anisomycin-treated (right), using
#9255 (green). Actin filaments were
labeled with DY-554 phalloidin (red).
Phospho-p38 MAPK (Thr180/Tyr182)
(D3F9) XP ® Rabbit mAb #4511: IHC
analysis of paraffin-embedded human
colon carcinoma using #4511.
MAPK
Erk1/2
p38-MAPK
α/β/γ/δ
JNK1-3 Erk5 Erk3/4 Erk7/8
MAPKAPK
Biological
Response
RSK1-4,
MNK1/2,
MSK1/2
Growth, Differentiation,
Proliferation, Development
MAPKAPK-2/3,
MSK1/2, MNK1
MAPKAPK-2,
MAPKAPK-3
Inflammation, Apoptosis,
Growth, Differentiation
RSK1-4
Growth,
Differentiation, Development
MAPKAPK-5
Inflammation, Apoptosis,
Differentiation
Select Reviews
Arthur, J.S. and Ley, S.C. (2013) Nat. Rev. Immunol. 13, 679–692. • Cargnello, M. and Roux, P.P. (2011) Microbiol. Mol. Biol.
Rev. 75, 50–83. • Cseh, B., Doma, E., and Baccarini, M. (2014) FEBS Lett. 588, 2398–2406. • Darling, N.J. and Cook, S.J.
(2014) Biochim. Biophys. Acta. 1843, 2150–2163. • Koul, H.K., Pal, M., and Koul, S. (2013) Genes Cancer 4, 342–359. •
Plotnikov, A., Zehorai, E., Procaccia, S., and Seger, R. (2011) Biochim. Biophys. Acta. 1813, 1619–1633. • Sehgal, V. and
Ram, P.T. (2013) Genes Cancer 4, 409–413.
42 For Research Use Only. Not For Use in Diagnostic Procedures. See pages 302 & 303 for Pathway Diagrams, Application, and Reactivity keys.
www.cellsignal.com/cstmapk 43