Title | DNA damage activates a spatially distinct late cytoplasmic cell-cycle checkpoint network controlled by MK2-mediated RNA stabilization. |
Publication Type | Journal Article |
Year of Publication | 2010 |
Authors | Reinhardt, HC, Hasskamp, P, Schmedding, I, Morandell, S, van Vugt, MATM, Wang, X, Linding, R, Ong, S-E, Weaver, D, Carr, SA, Yaffe, MB |
Journal | Mol Cell |
Volume | 40 |
Issue | 1 |
Pagination | 34-49 |
Date Published | 2010 Oct 8 |
ISSN | 1097-4164 |
Keywords | 3' Untranslated Regions, Active Transport, Cell Nucleus, Antibiotics, Antineoplastic, cdc25 Phosphatases, Cell Cycle, Cell Cycle Proteins, Cell Nucleus, Cytoplasm, DNA Damage, DNA Repair, Doxorubicin, Exoribonucleases, Feedback, Physiological, Head and Neck Neoplasms, HeLa Cells, Heterogeneous-Nuclear Ribonucleoproteins, Humans, Intracellular Signaling Peptides and Proteins, Mitosis, Nuclear Proteins, p38 Mitogen-Activated Protein Kinases, Phosphorylation, Protein Kinases, Protein-Serine-Threonine Kinases, RNA Interference, RNA Processing, Post-Transcriptional, RNA Stability, RNA, Messenger, RNA-Binding Proteins, Signal Transduction, Time Factors, Transfection, Ultraviolet Rays |
Abstract | Following genotoxic stress, cells activate a complex kinase-based signaling network to arrest the cell cycle and initiate DNA repair. p53-defective tumor cells rewire their checkpoint response and become dependent on the p38/MK2 pathway for survival after DNA damage, despite a functional ATR-Chk1 pathway. We used functional genetics to dissect the contributions of Chk1 and MK2 to checkpoint control. We show that nuclear Chk1 activity is essential to establish a G(2)/M checkpoint, while cytoplasmic MK2 activity is critical for prolonged checkpoint maintenance through a process of posttranscriptional mRNA stabilization. Following DNA damage, the p38/MK2 complex relocalizes from nucleus to cytoplasm where MK2 phosphorylates hnRNPA0, to stabilize Gadd45α mRNA, while p38 phosphorylates and releases the translational inhibitor TIAR. In addition, MK2 phosphorylates PARN, blocking Gadd45α mRNA degradation. Gadd45α functions within a positive feedback loop, sustaining the MK2-dependent cytoplasmic sequestration of Cdc25B/C to block mitotic entry in the presence of unrepaired DNA damage. Our findings demonstrate a critical role for the MK2 pathway in the posttranscriptional regulation of gene expression as part of the DNA damage response in cancer cells. |
DOI | 10.1016/j.molcel.2010.09.018 |
Alternate Journal | Mol. Cell |
PubMed ID | 20932473 |
PubMed Central ID | PMC3030122 |
Grant List | CA112967 / CA / NCI NIH HHS / United States ES015339 / ES / NIEHS NIH HHS / United States GM68762 / GM / NIGMS NIH HHS / United States P50 GM068762-09 / GM / NIGMS NIH HHS / United States R01 ES015339-05 / ES / NIEHS NIH HHS / United States R01 GM060594-09 / GM / NIGMS NIH HHS / United States U54 CA112967-07 / CA / NCI NIH HHS / United States |