scholarly journals Distinct Cell Cycle Timing Requirements for Extracellular Signal-Regulated Kinase and Phosphoinositide 3-Kinase Signaling Pathways in Somatic Cell Mitosis

2002 ◽  
Vol 22 (20) ◽  
pp. 7226-7241 ◽  
Author(s):  
Elisabeth C. Roberts ◽  
Paul S. Shapiro ◽  
Theresa Stines Nahreini ◽  
Gilles Pages ◽  
Jacques Pouyssegur ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cyclin B1 ◽  
Erk Pathway ◽  
Cycle Progression ◽  
Mitotic Entry ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Phosphoinositide 3 Kinase ◽  
And Function

ABSTRACT Mitogen-activated protein (MAP) kinase and phosphoinositide 3-kinase (PI3K) pathways are necessary for cell cycle progression into S phase; however the importance of these pathways after the restriction point is poorly understood. In this study, we examined the regulation and function of extracellular signal-regulated kinase (ERK) and PI3K during G2/M in synchronized HeLa and NIH 3T3 cells. Phosphorylation and activation of both the MAP kinase kinase/ERK and PI3K/Akt pathways occur in late S and persist until the end of mitosis. Signaling was rapidly reversed by cell-permeable inhibitors, indicating that both pathways are continuously activated and rapidly cycle between active and inactive states during G2/M. The serum-dependent behavior of PI3K/Akt versus ERK pathway activation indicates that their mechanisms of regulation differ during G2/M. Effects of cell-permeable inhibitors and dominant-negative mutants show that both pathways are needed for mitotic progression. However, inhibiting the PI3K pathway interferes with cdc2 activation, cyclin B1 expression, and mitotic entry, whereas inhibiting the ERK pathway interferes with mitotic entry but has little effect on cdc2 activation and cyclin B1 and retards progression from metaphase to anaphase. Thus, our study provides novel evidence that ERK and PI3K pathways both promote cell cycle progression during G2/M but have different regulatory mechanisms and function at distinct times.

scholarly journals Extracellular Signal-Regulated Kinase 2-Dependent Phosphorylation Induces Cytoplasmic Localization and Degradation of p21Cip1

2009 ◽  
Vol 29 (12) ◽  
pp. 3379-3389 ◽  
Author(s):  
Chae Young Hwang ◽  
Cheolju Lee ◽  
Ki-Sun Kwon
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Nuclear Antigen ◽  
Inhibitory Protein ◽  
Cycle Progression ◽  
Double Mutation ◽  
Extracellular Signal Regulated Kinase ◽  
Epidermal Growth Factor Treatment ◽  
Extracellular Signal

ABSTRACT p21Cip1 is an inhibitor of cell cycle progression that promotes G1-phase arrest by direct binding to cyclin-dependent kinase and proliferating cell nuclear antigen. Here we demonstrate that mitogenic stimuli, such as epidermal growth factor treatment and oncogenic Ras transformation, induce p21Cip1 downregulation at the posttranslational level. This downregulation requires the sustained activation of extracellular signal-regulated kinase 2 (ERK2), which directly interacts with and phosphorylates p21Cip1, promoting p21Cip1 nucleocytoplasmic translocation and ubiquitin-dependent degradation, thereby resulting in cell cycle progression. ERK1 is not likely involved in this process. Phosphopeptide analysis of in vitro ERK2-phosphorylated p21Cip1 revealed two phosphorylation sites, Thr57 and Ser130. Double mutation of these sites abolished ERK2-mediated p21Cip1 translocation and degradation, thereby impairing ERK2-dependent cell cycle progression at the G1/S transition. These results indicate that ERK2 activation transduces mitogenic signals, at least in part, by downregulating the cell cycle inhibitory protein p21Cip1.

scholarly journals Regulation of the G2–M cell cycle progression by the ERK5–NFκB signaling pathway

2007 ◽  
Vol 177 (2) ◽  
pp. 253-264 ◽  
Author(s):  
Kelly Cude ◽  
Yupeng Wang ◽  
Hyun-Jung Choi ◽  
Shih-Ling Hsuan ◽  
Honglai Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Signaling Pathway ◽  
Cancer Biology ◽  
Cell Cycle Progression ◽  
Nuclear Factor Κb ◽  
Cyclin B1 ◽  
M Cell ◽  
Cycle Progression ◽  
Mitotic Entry ◽  
Ribosomal S6 Kinase

Elucidation of mechanisms regulating cell cycle progression is of fundamental importance for cell and cancer biology. Although several genes and signaling pathways are implicated in G1–S regulation, less is known regarding the mechanisms controlling cell cycle progression through G2 and M phases. We report that extracellular signal–regulated kinase 5 (ERK5), a member of the mitogen-activated protein kinases, is activated at G2–M and required for timely mitotic entry. Stimulation of ERK5 activated nuclear factor κB (NFκB) through ribosomal S6 kinase 2 (RSK2)-mediated phosphorylation and degradation of IκB. Furthermore, selective inhibition of NFκB at G2–M phases substantially delayed mitotic entry and inhibited transcription of G2–M–specific genes, including cyclin B1, cyclin B2, Plk-1, and cdc25B. Moreover, inhibition of NFκB at G2–M diminished mitosis induced by constitutive activation of ERK5, providing a direct link between ERK5, NFκB, and regulation of G2–M progression. We conclude that a novel ERK5–NFκB signaling pathway plays a key role in regulation of the G2–M progression.

scholarly journals Extracellular Signal-regulated Kinase 1/2 Activity Is Not Required in Mammalian Cells during Late G2 for Timely Entry into or Exit from Mitosis

2006 ◽  
Vol 17 (12) ◽  
pp. 5227-5240 ◽  
Author(s):  
Mio Shinohara ◽  
Alexei V. Mikhailov ◽  
Julio A. Aguirre-Ghiso ◽  
Conly L. Rieder
Keyword(s):  
Cell Cycle ◽  
Mammalian Cells ◽  
Cell Cycle Progression ◽  
Spindle Assembly Checkpoint ◽  
Spindle Assembly ◽  
Live Cells ◽  
Cycle Progression ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Sustained Inhibition

Extracellular signal-regulated kinase (ERK)1/2 activity is reported to be required in mammalian cells for timely entry into and exit from mitosis (i.e., the G2-mitosis [G2/M] and metaphase-anaphase [M/A] transitions). However, it is unclear whether this involvement reflects a direct requirement for ERK1/2 activity during these transitions or for activating gene transcription programs at earlier stages of the cell cycle. To examine these possibilities, we followed live cells in which ERK1/2 activity was inhibited through late G2 and mitosis. We find that acute inhibition of ERK1/2 during late G2 and through mitosis does not affect the timing of the G2/M or M/A transitions in normal or transformed human cells, nor does it impede spindle assembly, inactivate the p38 stress-activated checkpoint during late G2 or the spindle assembly checkpoint during mitosis. Using CENP-F as a marker for progress through G2, we also show that sustained inhibition of ERK1/2 transiently delays the cell cycle in early/mid-G2 via a p53-dependent mechanism. Together, our data reveal that ERK1/2 activity is required in early G2 for a timely entry into mitosis but that it does not directly regulate cell cycle progression from late G2 through mitosis in normal or transformed mammalian cells.

scholarly journals Erk1/2 MAP kinases are required for epidermal G2/M progression

2009 ◽  
Vol 185 (3) ◽  
pp. 409-422 ◽  
Author(s):  
Phillip A. Dumesic ◽  
Florence A. Scholl ◽  
Deborah I. Barragan ◽  
Paul A. Khavari
Keyword(s):  
Cell Cycle ◽  
Epithelial Cells ◽  
Cell Cycle Progression ◽  
Map Kinases ◽  
Cyclin B1 ◽  
Epithelial Tissue ◽  
Cycle Progression ◽  
Extracellular Signal ◽  
Multiple Processes ◽  
Mitogen Activated Protein

Erk1/2 mitogen-activated protein kinases (MAPKs) are often hyperactivated in human cancers, where they affect multiple processes, including proliferation. However, the effects of Erk1/2 loss in normal epithelial tissue, the setting of most extracellular signal-regulated kinase (Erk)–associated neoplasms, are unknown. In epidermis, loss of Erk1 or Erk2 individually has no effect, whereas simultaneous Erk1/2 depletion inhibits cell division, demonstrating that these MAPKs are necessary for normal tissue self-renewal. Growth inhibition caused by Erk1/2 loss is rescued by reintroducing Erk2, but not by activating Erk effectors that promote G1 cell cycle progression. Unlike fibroblasts, in which Erk1/2 loss decreases cyclin D1 expression and induces G1/S arrest, Erk1/2 loss in epithelial cells reduces cyclin B1 and c-Fos expression and induces G2/M arrest while disrupting a gene regulatory network centered on cyclin B1–Cdc2. Thus, the cell cycle stages at which Erk1/2 activity is required vary by cell type, with Erk1/2 functioning in epithelial cells to enable progression through G2/M.

scholarly journals GINS2 affects cell viability, cell apoptosis, and cell cycle progression of pancreatic cancer cells via MAPK/ERK pathway

2020 ◽  
Vol 11 (16) ◽  
pp. 4662-4670
Author(s):  
Miao Zhang ◽  
Saifei He ◽  
Xing Ma ◽  
Ying Ye ◽  
Guoyu Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Pancreatic Cancer ◽  
Cell Viability ◽  
Cancer Cells ◽  
Cell Apoptosis ◽  
Cell Cycle Progression ◽  
Erk Pathway ◽  
Cycle Progression ◽  
Pancreatic Cancer Cells

scholarly journals The decision to enter mitosis: feedback and redundancy in the mitotic entry network

2009 ◽  
Vol 185 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Arne Lindqvist ◽  
Verónica Rodríguez-Bravo ◽  
René H. Medema
Keyword(s):  
Cell Cycle ◽  
Normal Cell ◽  
Cell Cycle Progression ◽  
Feedback Loops ◽  
Cyclin B ◽  
Cycle Progression ◽  
Mitotic Entry ◽  
Different Levels ◽  
Normal Cell Cycle

The decision to enter mitosis is mediated by a network of proteins that regulate activation of the cyclin B–Cdk1 complex. Within this network, several positive feedback loops can amplify cyclin B–Cdk1 activation to ensure complete commitment to a mitotic state once the decision to enter mitosis has been made. However, evidence is accumulating that several components of the feedback loops are redundant for cyclin B–Cdk1 activation during normal cell division. Nonetheless, defined feedback loops become essential to promote mitotic entry when normal cell cycle progression is perturbed. Recent data has demonstrated that at least three Plk1-dependent feedback loops exist that enhance cyclin B–Cdk1 activation at different levels. In this review, we discuss the role of various feedback loops that regulate cyclin B–Cdk1 activation under different conditions, the timing of their activation, and the possible identity of the elusive trigger that controls mitotic entry in human cells.

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