Assaying Cyclin-Dependent Kinase Activity in Synchronized Algal Cultures

2021 ◽  
pp. 73-88
Author(s):  
Kateřina Bišová
Keyword(s):  
Kinase Activity ◽  
Cyclin Dependent Kinase ◽  
Algal Cultures

Abstract 1470: The Kinase Activity of Cyclin-Dependent Kinase-9 is Required for Phosphorylation of p300 and its Histone Acetyltransferase Activity during Cardiomyocyte Hypertrophy

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Yoichi Sunagawa ◽  
Tatsuya Morimoto ◽  
Tomohide Takaya ◽  
Teruhisa Kawamura ◽  
Hiromichi Wada ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Kinase Activity ◽  
Histone Acetyltransferase ◽  
Single Amino Acid ◽  
Cardiomyocyte Hypertrophy ◽  
Cyclin Dependent Kinase ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Functional Relationships ◽  
Cdk9 Kinase Activity

Introduction: A zinc finger protein GATA4 is one of the factors involved in transcriptional regulation during myocardial cell hypertrophy and forms a complex with an intrinsic histone acetyltransferase (HAT), p300. HAT activity of p300 is required for acetylation and the transcriptional activity of GATA4 as well as for cardiomyocyte hypertrophy and the development of heart failure in vivo . By tandem affinity purification and mass spectrometric analyses, we identified cyclin-dependent kinase-9 (Cdk9), a component of positive transcription elongation factor b, as a novel GATA4-binding partner. Cdk9 also formed a complex with p300 as well as GATA4. However, the precise functional relationships among p300, GATA4, and Cdk9 remain unknown. Methods and Results: A series of GST pull-down assays revealed that the N-terminal of Cdk9 bound to the N-terminal zinc finger domain of GATA4 and C/H-3 domain of p300, respectively. By chromatin immunoprecipitation and DNA pull-down assay, we showed that GATA4 recruited Cdk9 onto GATA elements within the endothelin-1 promoter. Immuno-precipitation followed by Western blotting demonstrated that intact p300 induced not only the acetylation of GATA4, but also the interaction between GATA4 and Cdk9. Furthermore, p300 induced the hyperphosphorylation of RNA Pol II, suggesting that p300 is involved in the regulation of Cdk9 kinase activity. All of these effects were inhibited by the co-expression of a dominant-negative form (DN-) of p300. Conversely, Cdk9 induced not only the hyperphos-phorylation of RNA Pol II, but also the phosphorylation of p300. Notably, Cdk9 induced the acetylation and DNA binding of GATA4. However, DN-Cdk9, which loses its kinase activity by a single amino acid substitution, was unable to achieve these, suggesting the requirement of Cdk9 kinase activity for p300 HAT activity. Finally, a Cdk9 kinase inhibitor, DRB, inhibited phenylephrine-induced hypertrophic responses as well as the acetylation of GATA4 in cardiomyocytes. Conclusion: These findings demonstrate that Cdk9 is required for the phosphorylation of p300 and its HAT activity, and forms a functional complex with p300/GATA4 during cardiomyocyte hypertrophy.

Cyclin I and p35 determine the subcellular distribution of Cdk5

2015 ◽  
Vol 308 (4) ◽  
pp. C339-C347 ◽  
Author(s):  
Henning Hagmann ◽  
Yoshinori Taniguchi ◽  
Jeffrey W. Pippin ◽  
Hans-Michael Kauerz ◽  
Thomas Benzing ◽  
...  
Keyword(s):  
Subcellular Distribution ◽  
Cell Biology ◽  
Kinase Activity ◽  
Brain Slices ◽  
Axonal Guidance ◽  
Cell Fractionation ◽  
Cyclin Dependent Kinase ◽  
Immunofluorescence Labeling ◽  
Cellular Compartments ◽  
Cyclin I

The atypical cyclin-dependent kinase 5 (Cdk5) serves an array of different functions in cell biology. Among these are axonal guidance, regulation of intercellular contacts, cell differentiation, and prosurvival signaling. The variance of these functions suggests that Cdk5 activation comes to pass in different cellular compartments. The kinase activity, half-life, and substrate specificity of Cdk5 largely depend on specific activators, such as p25, p35, p39, and cyclin I. We hypothesized that the subcellular distribution of Cdk5 activators also determines the localization of the Cdk5 protein and sets the stage for targeted kinase activity within distinct cellular compartments to suit the varying roles of Cdk5. Cdk5 localization was analyzed in murine kidney and brain slices of wild-type and cyclin I- and/or p35-null mice by immunohistochemistry and in cultured mouse podocytes using immunofluorescence labeling, as well as cell fractionation experiments. The predominance of cyclin I mediates the nuclear localization of Cdk5, whereas the predominance of p35 results in a membranous localization of Cdk5. These findings were further substantiated by overexpression of cyclin I and p35 with altered targeting characteristics in human embryonic kidney 293T cells. These studies reveal that the subcellular localization of Cdk5 is determined by its specific activators. This results in the directed Cdk5 kinase activity in specific cellular compartments dependent on the activator present and allows Cdk5 to serve multiple independent roles.

scholarly journals Downregulation of Cdc2/CDK1 Kinase Activity Induces the Synthesis of Noninfectious Human Papillomavirus Type 31b Virions in Organotypic Tissues Exposed to Benzo[a]pyrene

2010 ◽  
Vol 84 (9) ◽  
pp. 4630-4645 ◽  
Author(s):  
Samina Alam ◽  
Brian S. Bowser ◽  
Michael J. Conway ◽  
Mohd Israr ◽  
Eric J. Ryndock ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Cellular Proliferation ◽  
Kinase Activity ◽  
Specific Inhibitor ◽  
Cell Interaction ◽  
Epidemiological Studies ◽  
Cyclin Dependent Kinase ◽  
Hpv Status ◽  
Increased Risk ◽  
Control Virus

ABSTRACT Epidemiological studies suggest that human papillomavirus (HPV)-infected women who smoke face an increased risk for developing cervical cancer. We have previously reported that exposure of HPV-positive organotypic cultures to benzo[a]pyrene (BaP), a major carcinogen in cigarette smoke, resulted in enhanced viral titers. Since BaP is known to deregulate multiple pathways of cellular proliferation, enhanced virion synthesis could result from carcinogen/host cell interaction. Here, we report that BaP-mediated upregulation of virus synthesis is correlated to an altered balance between cell cycle-specific cyclin-dependent kinase (CDK) activity profile compared with controls. Specifically, BaP treatment increased accumulation of hyperphosphorylated retinoblastoma protein (pRb) which coincided with increased cdc2/CDK1 kinase activity, but which further conflicted with the simultaneous upregulation of CDK inhibitors p16INK4 and p27KIP1, which normally mediate pRb hypophosphorylation. In contrast, p21WAF1 and p53 levels remained unchanged. Under these conditions, CDK6 and CDK2 kinase activities were decreased, whereas CDK4 kinase activity remained unchanged. The addition of purvalanol A, a specific inhibitor of CDK1 kinase, to BaP-treated cultures, resulted in the production of noninfectious HPV type 31b (HPV31b) particles. In contrast, infectivity of control virus was unaffected by purvalanol A treatment. BaP targeting of CDK1 occurred independently of HPV status, since BaP treatment also increased CDK1 activity in tissues derived from primary keratinocytes. Our data indicate that HPV31b virions synthesized in the presence of BaP were dependent on BaP-mediated alteration in CDK1 kinase activity for maintaining their infectivity.

Use of CDK1 and CDK2 activity to predict renal cell cancer recurrence.

2011 ◽  
Vol 29 (7_suppl) ◽  
pp. 341-341
Author(s):  
F. Hongo ◽  
N. Takaha ◽  
Y. Kimura ◽  
T. Nakamura ◽  
K. Mikami ◽  
...  
Keyword(s):  
Clinical Setting ◽  
Renal Cell ◽  
Kinase Activity ◽  
Specific Activity ◽  
Cell Cancer ◽  
Cancer Recurrence ◽  
Progression Free Survival ◽  
Cyclin Dependent Kinase ◽  
Human Renal Cell Carcinoma ◽  
Cdk2 Activity

341 Background: We established original methods enabling simultaneous analysis of protein expressions and kinase activities of the CDK (cyclin-dependent kinase) molecules in lysate of tumor tissue in a clinical setting (C2P technology, Ishihara et al: Biochim Biophys Acta. 1741; 226-233, 2005). The clinical utility of the technology was first evaluated in breast cancer, and combination analysis of CDK1 and CDK2 activity was shown to be a significant prognostic indicator for relapse (Kim et al. Ann Oncol. 19;68-72,2009). The objective of our study is to evaluate the efficacy of CDK1 and CDK2 activity as a prognostic marker in human renal cell carcinoma (RCC). Methods: Surgical specimens were obtained from 115 patients with RCC without metastasis. These patients were selected randomly for this study. Protein expression and kinase activity of CDKs and cyclins were analyzed using a newly developed assay system. The system to measure the CDK specific activity (SA) is named C2Ps (Sysmex, Kobe, Japan). We then examined the specific activities of CDK1 and CDK2 and calculated CDK2/CDK1 ratio in RCC. Also, risk score (RS) was examined as described in previous study (JGH van Nes et al: Br J Cancer. 100; 494-500, 2009). Cut off value was calculated by ROC analysis. Results: 115 cases were tested, though 32 cases were excluded of low sample quality (30 cases) and of assay failure (2 cases). 83 cases were analyzed. They included 63 male and 20 female patients, ranging in age from 19 to 83 years. At a median follow up of 33 months (1-109M), tumor with low CDK2/CDK1 ratio showed significantly better 5-year progression-free survival (PFS) than those with high CDK2/CDK1 ratio (91.2% vs. 51.6%, p=0.0016). Also, RS enabled the classification of RCCs into high-risk and low-risk groups, patients with tumors classified as low RS showed better PFS than patients with tumors with high RS (88.9% vs. 63.9%, p=0.0488). Conclusions: CDK1 specific activity of tumors and the CDK2 specific activity are both associated with recurrence and prognosis. Analysis of cyclin-dependent kinase activity in the clinical setting could be a powerful approach for predicting cancer recurrence and prognosis in RCC after surgery and has potential for use as a routine laboratory test. No significant financial relationships to disclose.

scholarly journals E2f1, E2f2, and E2f3 Control E2F Target Expression and Cellular Proliferation via a p53-Dependent Negative Feedback Loop

2007 ◽  
Vol 27 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Cynthia Timmers ◽  
Nidhi Sharma ◽  
Rene Opavsky ◽  
Baidehi Maiti ◽  
Lizhao Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Target Genes ◽  
Cellular Proliferation ◽  
Kinase Activity ◽  
Cyclin Dependent Kinase ◽  
Control Of Gene Expression ◽  
Target Gene Expression ◽  
Rb Phosphorylation ◽  
P53 Target Genes

ABSTRACT E2F-mediated control of gene expression is believed to have an essential role in the control of cellular proliferation. Using a conditional gene-targeting approach, we show that the targeted disruption of the entire E2F activator subclass composed of E2f1, E2f2, and E2f3 in mouse embryonic fibroblasts leads to the activation of p53 and the induction of p53 target genes, including p21 CIP1 . Consequently, cyclin-dependent kinase activity and retinoblastoma (Rb) phosphorylation are dramatically inhibited, leading to Rb/E2F-mediated repression of E2F target gene expression and a severe block in cellular proliferation. Inactivation of p53 in E2f1-, E2f2-, and E2f3-deficient cells, either by spontaneous mutation or by conditional gene ablation, prevented the induction of p21 CIP1 and many other p53 target genes. As a result, cyclin-dependent kinase activity, Rb phosphorylation, and E2F target gene expression were restored to nearly normal levels, rendering cells responsive to normal growth signals. These findings suggest that a critical function of the E2F1, E2F2, and E2F3 activators is in the control of a p53-dependent axis that indirectly regulates E2F-mediated transcriptional repression and cellular proliferation.

scholarly journals BRCA1 Is Phosphorylated at Serine 1497 In Vivo at a Cyclin-Dependent Kinase 2 Phosphorylation Site

1999 ◽  
Vol 19 (7) ◽  
pp. 4843-4854 ◽  
Author(s):  
Heinz Ruffner ◽  
Wei Jiang ◽  
A. Grey Craig ◽  
Tony Hunter ◽  
Inder M. Verma
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Kinase Activity ◽  
Phosphorylation Site ◽  
Cyclin A ◽  
Dominant Negative ◽  
Protein Kinase Activity ◽  
Cyclin Dependent Kinase

ABSTRACT BRCA1 is a cell cycle-regulated nuclear protein that is phosphorylated mainly on serine and to a lesser extent on threonine residues. Changes in phosphorylation occur in response to cell cycle progression and DNA damage. Specifically, BRCA1 undergoes hyperphosphorylation during late G1 and S phases of the cell cycle. Here we report that BRCA1 is phosphorylated in vivo at serine 1497 (S1497), which is part of a cyclin-dependent kinase (CDK) consensus site. S1497 can be phosphorylated in vitro by CDK2-cyclin A or E. BRCA1 coimmunoprecipitates with an endogenous serine-threonine protein kinase activity that phosphorylates S1497 in vitro. This cellular kinase activity is sensitive to transfection of a dominant negative form of CDK2 as well as the application of the CDK inhibitors p21 and butyrolactone I but not p16. Furthermore, BRCA1 coimmunoprecipitates with CDK2 and cyclin A. These results suggest that the endogenous kinase activity is composed of CDK2-cyclin complexes, at least in part, concordant with the G1/S-specific increase in BRCA1 phosphorylation.

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