## Abstract When the brain is damaged, astrocytes often cause hyperplasia resulting in glial scar formation at the injured sites. Endothelins (ETs) have been shown to be involved in the pathophysiologic responses of astrocytes, including proliferation. In this study, we examined the mechanisms unde
PAK4 is required for regulation of the cell-cycle regulatory protein p21, and for control of cell-cycle progression
✍ Scribed by Tanya Nekrasova; Dr. Audrey Minden
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 979 KB
- Volume
- 112
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The serine/threonine kinase PAK4 regulates cytoskeletal architecture, and controls cell proliferation and survival. In most adult tissues PAK4 is expressed at low levels, but overexpression of PAK4 is associated with uncontrolled proliferation, inappropriate cell survival, and oncogenic transformation. Here we have studied for the first time, the role for PAK4 in the cell cycle. We found that PAK4 levels peak dramatically but transiently in the early part of G1 phase. Deletion of Pak4 was also associated with an increase in p21 levels, and PAK4 was required for normal p21 degradation. In serum‐starved cells, the absence of PAK4 led to a reduction in the amount of cells in G1, and an increase in the amount of cells in G2/M phase. We propose that the transient increase in PAK4 levels at early G1 reduces p21 levels, thereby abrogating the activity of CDK4/CDK6 kinases, and allowing cells to proceed with the cell cycle in a precisely coordinated way. J. Cell. Biochem. 112: 1795–1806, 2011. © 2011 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
## Abstract To study the putative role of de novo synthesis of glutathione (GSH) in the regulation of the cell cycle, we exposed NIH‐3T3 cells to buthionine sulfoximine (BSO) and analysed cell cycle kinetics with continuous bromodeoxyuridine (BrdU) labeling and bivariate Hoechst 33258/ethidium brom
## Abstract The generation of knock‐out mice for E2F4 gene expression has suggested a role for this transcription factor in establishing and/or maintaining the intestinal crypt compartment. Having previously demonstrated that E2F4 is cytoplasmic in quiescent‐differentiated cells but nuclear in grow
## Abstract Ataxia telangiectasia mutated protein (ATM) is a member of the phosphatidylinositol‐3 kinase (PI3K) family, which has a role in the cellular response to DNA double‐strand breaks (DSBs). In the present study, we evaluated the role of ATM in cell‐cycle control in dopaminergic rat neurobla
The cell line M-07e requires either Interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF) for proliferation in vitro. Cells deprived of growth factor for up to 48 hours remain viable but no longer divide. The growthfactor-deprived M-07e cells begin to divide within 48 hou