TY - JOUR
T1 - Delayed cell cycle progression in selenoprotein w-depleted cells is regulated by a mitogen-activated protein kinase kinase 4-p38/c-Jun NH 2-terminal kinase-p53 pathway
AU - Hawkes, Wayne Chris
AU - Alkan, Zeynep
PY - 2012/8/10
Y1 - 2012/8/10
N2 - Selenoprotein W (SEPW1) is a ubiquitous, highly conserved thioredoxin-like protein whose depletion causes a transient p53- and p21 Cip1-dependent G 1-phase cell cycle arrest in breast and prostate epithelial cells. SEPW1 depletion increases phosphorylation of Ser-33 in p53, which is associated with decreased p53 ubiquitination and stabilization of p53. We report here that delayed cell cycle progression, Ser-33 phosphorylation, and p53 nuclear accumulation from SEPW1 depletion require mitogen-activated protein kinase kinase 4 (MKK4). Silencing MKK4 rescued G 1 arrest, Ser-33 phosphorylation, and nuclear accumulation of p53 induced by SEPW1 depletion, but silencing MKK3, MKK6, or MKK7 did not. SEPW1 silencing did not change the phosphorylation state of MKK4 but increased total MKK4 protein. Silencing p38γ, p38δ, or JNK2 partially rescued G 1 arrest from SEPW1 silencing, suggesting they signal downstream from MKK4. These results imply that SEPW1 silencing increases MKK4, which activates p38γ, p38δ, and JNK2 to phosphorylate p53 on Ser-33 and cause a transient G 1 arrest.
AB - Selenoprotein W (SEPW1) is a ubiquitous, highly conserved thioredoxin-like protein whose depletion causes a transient p53- and p21 Cip1-dependent G 1-phase cell cycle arrest in breast and prostate epithelial cells. SEPW1 depletion increases phosphorylation of Ser-33 in p53, which is associated with decreased p53 ubiquitination and stabilization of p53. We report here that delayed cell cycle progression, Ser-33 phosphorylation, and p53 nuclear accumulation from SEPW1 depletion require mitogen-activated protein kinase kinase 4 (MKK4). Silencing MKK4 rescued G 1 arrest, Ser-33 phosphorylation, and nuclear accumulation of p53 induced by SEPW1 depletion, but silencing MKK3, MKK6, or MKK7 did not. SEPW1 silencing did not change the phosphorylation state of MKK4 but increased total MKK4 protein. Silencing p38γ, p38δ, or JNK2 partially rescued G 1 arrest from SEPW1 silencing, suggesting they signal downstream from MKK4. These results imply that SEPW1 silencing increases MKK4, which activates p38γ, p38δ, and JNK2 to phosphorylate p53 on Ser-33 and cause a transient G 1 arrest.
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U2 - 10.1074/jbc.M112.346593
DO - 10.1074/jbc.M112.346593
M3 - Article
C2 - 22730327
AN - SCOPUS:84865016316
VL - 287
SP - 27371
EP - 27379
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 33
ER -