scholarly journals Variation in Growth Rate between Arabidopsis Ecotypes Is Correlated with Cell Division and A-Type Cyclin-Dependent Kinase Activity

2002 ◽  
Vol 129 (2) ◽  
pp. 854-864 ◽  
Author(s):  
Gerrit T.S. Beemster ◽  
Kristof De Vusser ◽  
Evelien De Tavernier ◽  
Kirsten De Bock ◽  
Dirk Inzé
Keyword(s):  
Growth Rate ◽  
Cell Division ◽  
Kinase Activity ◽  
Cyclin Dependent Kinase

Increased amount of a 25-kilodalton phosphoprotein after v-mos transfection of CHO cells

1988 ◽  
Vol 8 (11) ◽  
pp. 4685-4691
Author(s):  
J K Mayo ◽  
K E Sampson ◽  
L D Adams ◽  
E R Crumm ◽  
S L Kelly ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cho Cells ◽  
Kinase Activity ◽  
Chinese Hamster ◽  
Temperature Sensitive ◽  
Serine Threonine Kinase ◽  
Dependent Protein Kinase ◽  
Threonine Kinase ◽  
Dependent Protein ◽  
A Cell

We transfected Chinese hamster ovary (CHO) cells with a cloned v-mos gene (pHT25). The mos family of oncogenes has previously been shown to have serine-threonine kinase activity. This kinase activity may be required for oncogenic transformation, although its exact biological role is unknown. We found that the transfected cells had an altered morphology, a slower doubling time, and an apparent increase in the amount of a 25-kilodalton (kDa) phosphoprotein that appeared to be of low abundance. Transfection of CHO cells with a cloned temperature-sensitive mos gene (ts159) led to isolation of a cell line that showed the presence of the 25-kDa phosphoprotein at the permissive but not at the nonpermissive temperature, suggesting a direct relationship between mos activity and the presence of this phosphoprotein. The characteristics of altered morphology and depressed growth rate were reminiscent of changes seen after the activation of the cyclic AMP-dependent protein kinase (PKA) in CHO cells. However, PKA activation did not stimulate phosphorylation of this 25-kDa protein, nor was there a change in total PKA activity in these cells. We suggest that the increased presence of the 25-kDa phosphoprotein is a consequence of the v-mos transfection and that it may be involved in the change of morphology and growth rate seen in the CHO cells. Phosphorylation of this protein may be a useful marker of mos and have some functional importance in the transformation of cells by the v-mos oncogene.

Activity and expression pattern of cyclin-dependent kinase 5 in the embryonic mouse nervous system

Development ◽  
1993 ◽  
Vol 119 (4) ◽  
pp. 1029-1040 ◽  
Author(s):  
L.H. Tsai ◽  
T. Takahashi ◽  
V.S. Caviness ◽  
E. Harlow
Keyword(s):  
Nervous System ◽  
Cell Division ◽  
Cell Division Cycle ◽  
Adult Brain ◽  
Cyclin Dependent Kinase ◽  
Proliferating Cells ◽  
Embryonic Mouse ◽  
Postmitotic Neurons ◽  
Cyclin Dependent Kinase 5 ◽  
Expression And Activity

Cyclin-dependent kinase 5 (cdk5) was originally isolated on the basis of its close primary sequence homology to the human cdc2 serine/threonine kinase, the prototype of the cyclin-dependent kinases. While kinase activities of both cdc2 and cdk2 are detected in proliferating cells and are essential for cells to progress through the key transition points of the cell cycle, cdk5 kinase activity has been observed only in lysates of adult brain. In this study, we compared the activity and expression of cdk5 with that of cdc2 and cdk2 in the embryonic mouse forebrain. The expression and activity of cdk5 increased progressively as increasing numbers of cells exited the proliferative cycle. In contrast, the expression and activity of cdc2 and cdk2 were maximum at gestational day 11 (E11) when the majority of cells were proliferating and fell to barely detectable levels at E17 at the end of the cytogenetic period. Immunohistochemical studies showed that cdk5 is expressed in postmitotic neurons but not in glial cells or mitotically active cells. Expression of cdk5 was concentrated in fasciculated axons of postmitotic neurons. In contrast to other cell division cycle kinases to which it is closely related, cdk5 appears not to be expressed in dividing cells in the developing brain. These observations suggest that cdk5 may have a role in neuronal differentiation but not in the cell division cycle in the embryonic nervous system.

scholarly journals Talin mechanosensitivity is modulated by a direct interaction with cyclin-dependent kinase-1

2021 ◽  
Author(s):  
Rosemarie E. Gough ◽  
Matthew C. Jones ◽  
Thomas Zacharchenko ◽  
Shimin Le ◽  
Miao Yu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Adhesion ◽  
Cell Division ◽  
Mechanical Response ◽  
Direct Interaction ◽  
Cyclin Dependent Kinase ◽  
Cell Cycle Regulator ◽  
Direct Binding

AbstractTalin is a mechanosensitive component of adhesion complexes that directly couples integrins to the actin cytoskeleton. In response to force, talin undergoes switch-like behaviour of its multiple rod domains that modulate interactions with its binding partners. Cyclin-dependent kinase-1 (CDK1) is a key regulator of the cell cycle, exerting its effects through synchronised phosphorylation of a large number of protein targets. CDK1 activity also maintains adhesion during interphase, and its inhibition is a prerequisite for the tightly choreographed changes in cell shape and adhesiveness that are required for successful completion of mitosis. Using a combination of biochemical, structural and cell biological approaches, we demonstrate a direct interaction between talin and CDK1 that occurs at sites of integrin-mediated adhesion. Mutagenesis demonstrated that CDK1 contains a functional talin-binding LD motif, and the binding site within talin was pinpointed to helical bundle R8 through the use of recombinant fragments. Talin also contains a consensus CDK1 phosphorylation motif centred on S1589; a site that was phosphorylated by CDK1in vitro. A phosphomimetic mutant of this site within talin lowered the binding affinity of KANK and weakened the mechanical response of the region, potentially altering downstream mechanotransduction pathways. The direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, therefore provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division in multicellular organisms.SummaryThe direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division.

scholarly journals p12DOC-1 Is a Novel Cyclin-Dependent Kinase 2-Associated Protein

2000 ◽  
Vol 20 (17) ◽  
pp. 6300-6307 ◽  
Author(s):  
Satoru Shintani ◽  
Hiroe Ohyama ◽  
Xue Zhang ◽  
Jim McBride ◽  
Kou Matsuo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Ectopic Expression ◽  
Cell Division Cycle ◽  
Cyclin Dependent Kinase ◽  
Data Support ◽  
Normal Keratinocytes ◽  
Active Pool ◽  
Growth Suppressor

ABSTRACT Regulated cyclin-dependent kinase (CDK) levels and activities are critical for the proper progression of the cell division cycle. p12DOC-1 is a growth suppressor isolated from normal keratinocytes. We report that p12DOC-1 associates with CDK2. More specifically, p12DOC-1 associates with the monomeric nonphosphorylated form of CDK2 (p33CDK2). Ectopic expression of p12DOC-1 resulted in decreased cellular CDK2 and reduced CDK2-associated kinase activities and was accompanied by a shift in the cell cycle positions of p12DOC-1transfectants (↑ G1 and ↓ S). The p12DOC-1-mediated decrease of CDK2 was prevented if the p12DOC-1 transfectants were grown in the presence of the proteosome inhibitor clasto-lactacystin β-lactone, suggesting that p12DOC-1 may target CDK2 for proteolysis. A CDK2 binding mutant was created and was found to revert p12DOC-1-mediated, CDK2-associated cell cycle phenotypes. These data support p12DOC-1 as a specific CDK2-associated protein that negatively regulates CDK2 activities by sequestering the monomeric pool of CDK2 and/or targets CDK2 for proteolysis, reducing the active pool of CDK2.

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