Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
CDK11 (
cyclin-dependent kinase
11, formerly known as PITSLRE) is a member of the p34cdc2-related kinases. It has been previously shown to be involved in a variety of different cellular processes including RNA processing, apoptosis, and cell cycle progression. It is encoded by two different but highly similar genes, Cdc2L1 (cell division control 2 like 1) and Cdc2L2 (cell division control 2 like 2). Previous studies from our group identified and characterized the transcriptional regulation of the human Cdc2L2 gene promoter. The current studies identify and characterize the Cdc2L1 gene promoter. We cloned the promoter and elucidated the different transcriptional regulatory elements that reside within the 5' region of the gene. Deletion analysis of the promoter showed a region of nucleotides -152 to +11 to be necessary for basal transcription of the Cdc2L1 gene. Sequencing analysis found this region of the promoter to be highly GC-rich but is lacking both TATA and CAAT boxes. There are several different transcription factor binding sites that are consensus or near consensus found within this region. The potential binding sites include two Ets-1 sites, one Skn-1 site, and one
E2F-1
site. Transfection studies of various site-directed mutagenesis clones for these different sites revealed that both Ets-1 sites play critical roles in sustained transcriptional activity as well as Skn-1. Chromatin immunoprecipitation of the endogenous promoter with Ets-1 and Skn-1 verified an in vivo association of Ets-1 and Skn-1 transcription factors with the endogenous promoter. These results, in addition to our Cdc2L2 results, lead to the further comprehension of the fundamental mechanisms dictating CDK11 gene expression through the Cdc2L1 gene promoter.
...
PMID:Isolation and characterization of the human Cdc2L1 gene promoter. 1565 72
The pocket protein family of tumor suppressors, and Rb specifically, have been implicated as controlling terminal differentiation in many tissues, including the heart. To establish the biological functions of Rb in the heart and overcome the early lethality caused by germ line deletion of Rb, we used a Cre/loxP system to create conditional, heart-specific Rb-deficient mice. Mice that are deficient in Rb exclusively in cardiac myocytes (CRbL/L) are born with the expected Mendelian distribution, and the adult mice displayed no change in heart size, myocyte cell cycle distribution, myocyte apoptosis, or mechanical function. Since both Rb and p130 are expressed in the adult myocardium, we created double-knockout mice (CRbL/L p130-/-) to determine it these proteins have a shared role in regulating cardiac myocyte cell cycle progression. Adult CRbL/L p130-/- mice demonstrated a threefold increase in the heart weight-to-body weight ratio and showed increased numbers of bromodeoxyuridine- and phosphorylated histone H3-positive nuclei, consistent with persistent myocyte cycling. Likewise, the combined deletion of Rb plus p130 up-regulated myocardial expression of Myc,
E2F-1
, and G1
cyclin-dependent kinase
activities, synergistically. Thus, Rb and p130 have overlapping functional roles in vivo to suppress cell cycle activators, including Myc, and maintain quiescence in postnatal cardiac muscle.
...
PMID:Overlapping roles of pocket proteins in the myocardium are unmasked by germ line deletion of p130 plus heart-specific deletion of Rb. 1574 40
Overexpression of the transcription factor
E2F-1
induces apoptosis in a variety of carcinoma cells and inactivates murine double minute protein 2, a factor associated with poor prognosis in soft tissue sarcomas. We have shown previously that the double-stranded RNA-activated
protein kinase
PKR plays an important role in mediating this apoptotic response in carcinoma cells to
E2F-1
. We sought to evaluate the potential of
E2F-1
gene therapy in soft tissue sarcomas and to study the involvement of PKR in the response to
E2F-1
overexpression in mesenchymal cells. A replication-deficient adenovirus carrying the
E2F-1
gene (Ad5E2F) was used to induce
E2F-1
overexpression in the p53 mutated leiomyosarcoma cell line, SKLMS-1. Western blot analysis confirmed
E2F-1
overexpression and up-regulation of the antiapoptotic factor Bcl-2 48 hours following infection with Ad5E2F. Apoptosis in Ad5E2F-treated cells was confirmed by fluorescence-activated cell sorting analysis and by poly(ADP-ribose) polymerase cleavage and DNA fragmentation assays. Vector-dependent up-regulation of PKR correlated with the amount of Ad5E2F-induced apoptosis. In vivo treatment of SKLMS-1 tumor-bearing BALB/c mice with intratumoral injections of Ad5E2F at a dose of 2 x 10(10) viral particles resulted in significant inhibition in tumor growth compared with control-treated animals (P < 0.016). Complete disappearance of all tumors was seen in two of seven mice in the Ad5E2F-treated animals. Immunohistochemical analysis of tumor specimens showed overexpression of
E2F-1
and up-regulation of PKR in Ad5E2F-treated tumors. These findings show that adenovirus-mediated overexpression of
E2F-1
results in up-regulation of PKR and significant growth suppression of leiomyosarcomas in vivo. Taken together, these data suggest that
E2F-1
gene therapy and PKR modulation might be a promising treatment strategy for these tumors that are highly resistant to conventional therapies.
...
PMID:Gene therapy with E2F-1 up-regulates the protein kinase PKR and inhibits growth of leiomyosarcoma in vivo. 1627 92
The pRb (retinoblastoma protein) tumour suppressor protein has a crucial role in regulating the G1- to S-phase transition, and its phosphorylation by cyclin-dependent kinases is an established and important mechanism in controlling pRb activity. In addition, the targeted acetylation of lysine (K) residues 873/874 in the carboxy-terminal region of pRb located within a
cyclin-dependent kinase
-docking site hinders pRb phosphorylation and thereby retains pRb in an active state of growth suppression. Here, we report that the acetylation of pRb K873/874 occurs in response to DNA damage and that acetylation regulates the interaction between the C-terminal
E2F-1
-specific domain of pRb and
E2F-1
. These results define a new role for pRb acetylation in the DNA damage signalling pathway, and suggest that the interaction between pRb and
E2F-1
is controlled by DNA-damage-dependent acetylation of pRb.
...
PMID:DNA-damage-responsive acetylation of pRb regulates binding to E2F-1. 1637 12
Preclinical studies were performed of a novel selective imidazopyridine
cyclin-dependent kinase
(cdk) inhibitor, AZ703. In vitro kinase assays showed that IC50 values for AZ703 against purified cyclin E/cdk2 and cyclin B/cdk1 were 34 and 29 nmol/L, respectively. In contrast, the IC50 against cdk4 was 10 micromol/L. AZ703 also inhibited cdk7 and cdk9 with IC50 values of 2.1 micromol/L and 521 nmol/L, respectively. Treatment of U2OS, NCI-H1299, and A549 cells for 24 hours resulted in growth arrest involving multiple cell cycle phases. At low drug concentrations (< 2 micromol/L), G2 arrest predominated, whereas at higher concentrations (> or = 2 micromol/L), S-G2 arrest was observed. When cells were synchronized in G1 by starvation and released into AZ703, a block in G1 occurred that was not evident in exponentially growing cells. Cell cycle arrest was associated with reduced phosphorylation of the retinoblastoma protein and p27(Kip1) at cdk2 phospho-sites. Following longer exposures, apoptosis was evident. Cells were further sensitized to AZ703 following recruitment to S phase by synchronization. Consistent with the inhibition of cdks during S and G2 that modulate the activity and stability of
E2F-1
, AZ703 treatment induced
E2F-1
expression. In U2OS and NCI-H1299 cells engineered to inducibly express the dominant-negative mutant
E2F-1
(1-374), expression of the mutant decreased AZ703-mediated apoptosis, indicating dependence on
E2F-1
transcriptional targets. AZ703-induced apoptosis in NCI-H1299 cells was enhanced by small interfering RNA-mediated depletion of cdk9, which caused reduced levels of Mcl-1 and XIAP, suggesting that cdk2, cdk1, and cdk9 represent a rational subset of family members for drug targeting.
...
PMID:AZ703, an imidazo[1,2-a]pyridine inhibitor of cyclin-dependent kinases 1 and 2, induces E2F-1-dependent apoptosis enhanced by depletion of cyclin-dependent kinase 9. 1639 59
Brd2 is a novel
protein kinase
and plays a role in cell cycle-responsive transcription. Recent studies show that Brd2 contributes to
E2F-1
regulated cell cycle progression. In this process, Brd2 exhibits scaffold or transcriptional adapter functions and mediates recruitment of both
E2F-1
transcription factors and chromatin-remodelling activity to the
E2F-1
-resposive promoter. In the present study, we show that Brd2 is also a TBP-associated protein and a 26 amino acids peptide in the first bromodomain of Brd2 is essential for Brd2-TBP interaction. We found that serum stimulation of serum starved NIH/3T3 cells efficiently induces the formation of the Brd2-
E2F-1
-TBP complex in vivo. In this process, Brd2 plays a pivotal role in the recruitment of TBP into a
E2F-1
transcriptional complex, as tested in overexpression assay and at the endogenous level. Furthermore, the 26 amino acid peptide that mediates Brd2-TBP interaction is proved to be critical for Brd2-dependent transactivation on
E2F-1
-responsive promoters, and moreover, Brd2 and
E2F-1
may cooperatively participate in various serum-induced transactivation processes in Luciferase-reporter assays. Thus taken together, because Brd2 may recruit a HAT in its transactivational complex and
E2F-1
has been found to stimulate transcription by recruiting acetyltransferase and cofactors GCN5, we predict that Brd2 and
E2F-1
may act in a cooperative way to introduce an optimal environment for TBP binding to the TATA-element of gene promoters.
...
PMID:Brd2 is a TBP-associated protein and recruits TBP into E2F-1 transcriptional complex in response to serum stimulation. 1711 Nov 93
Over the last few decades, understanding of the mechanisms involved in the process of neuronal cell death has grown. Recent findings have established that DNA damage, and specifically ataxia telangiectasia mutated protein (ATM), is key to the cascade of regulation of neuronal apoptosis. Another characteristic common to all neurodegenerative diseases is oxidative stress. Likewise, a common feature in the brain of patients with neurodegenerative diseases such as Alzheimer's and Parkinson's diseases and other neurological disorders is the expression of proteins involved in cell-cycle control. In the process of re-entry in the cell cycle, an additional component, transcription factor
E2F-1
, also involved in the regulation of apoptosis, is expressed. Finally, in this complex puzzle, mitochondrial activation with the release of proteins and the activation of cystein proteases, specifically caspase-3, is prominent in the last step of neuronal apoptosis. This review focuses on the role of ATM activation and its re-entry into the cell cycle in neurons as a potential target for the prevention of neuronal apoptosis. We suggest the mechanisms by which ATM and
E2F-1
orchestrate the apoptotic process. Among them, p53 could be a common point on this apoptotic route. Finally, we put forward drugs that are now being studied experimentally, such as p53 inhibitors, ATM inhibitors and
cyclin-dependent kinase
(CDKs) inhibitors, for the treatment of neurodegenerative diseases.
...
PMID:Inhibition of ataxia telangiectasia-p53-E2F-1 pathway in neurons as a target for the prevention of neuronal apoptosis. 1797 59
The survival rate of children with advanced neuroblastoma (NB) is dismal despite intensive multimodal therapy. The limited efficacy and the frequent and serious side effects of currently used therapeutic regimens necessitate the development of new, less toxic treatment strategies. This study shows that the histone deacetylase inhibitor Helminthosporium carbonum (HC)-toxin suppresses the malignant phenotype of both established NB cell lines and primary NB cells with and without amplified MYCN at dosages lower than 20 nM. HC-toxin induces cell cycle arrest and apoptosis as well as neuronal differentiation and diminishes both colony formation and invasive growth. These cellular changes are accompanied by the transcriptional repression of cell cycle regulators of the retinoblastoma (RB) tumor suppressor network found at high levels in NBs with poor prognosis, like
E2F-1
and its targets Skp2, N-myc, Mad2 and survivin. The levels of the hypophosphorylated active form of RB, and of
cyclin-dependent kinase
inhibitors including p15(INK4b), p16(INK4a), p21(cip1/waf-1) and p27(kip1) are increased. In conclusion, nanomolar doses of the HDACI HC-toxin cause a shift to a differentiated and benign phenotype of NB cells that is associated with an activation of the RB tumor suppressor network.
...
PMID:Histone deacetylase inhibitor Helminthosporium carbonum (HC)-toxin suppresses the malignant phenotype of neuroblastoma cells. 1807 52
This study was conducted to further elucidate the possible mechanisms by which esculetin, a coumarin compound, exerts its anti-proliferative action on cultured human monocytic leukemia U937 cells. The inhibitory effects of esculetin on cell viability were found to be associated with a G1 arrest in cell cycle progression that was concomitant with an inhibition of cyclin E and an induction of
cyclin-dependent kinase
(Cdk) inhibitor p21/WAF1/CIP1 in a p53-independent manner. Cells that were treated with esculetin showed increased binding of p21 with Cdk2 and Cdk4 that was paralleled by a marked decrease in the Cdk2 and Cdk4 kinase activities with no change in their expression. We also observed that down-regulation of the phosphorylation of retinoblastoma protein (pRB) by this compound was associated with enhanced binding of pRB and the transcription factor
E2F-1
. Further investigation showed that inhibition of the extracellular-regulated kinase (ERK) signaling pathway reduced the induction of p21 and the inhibition of pRB phosphorylation and cyclin E expression by esculetin, which in turn overcame the G1 arrest and growth inhibition that was induced by esculetin. These data demonstrate that the ERK pathway participates in p21 induction and subsequently leads to a decrease in the kinase activity of Cdks and inhibition of pRB phosphorylation in esculetin-mediated G1 arrest of U937 cells.
...
PMID:Involvement of extracellular signal-related kinase signaling in esculetin induced G1 arrest of human leukemia U937 cells. 1822 60
Overexpression of the transcription factor
E2F-1
induces apoptosis in tumor cells. This apoptotic effect is partly mediated through the induction of the double-stranded RNA-activated
protein kinase
(PKR). Here, we investigate if agents that upregulate PKR could enhance the apoptotic effect of
E2F-1
overexpression in liver tumors. In human hepatocellular carcinoma (HCC) cells (Hep3B, HepG2, Huh7), adenovirus-mediated overexpression of
E2F-1
(AdCMV-E2F) transcriptionally increased PKR mRNA. The subsequent increase of total and phosphorylated PKR protein was followed by induction of apoptosis. When AdCMV-E2F was combined with the PKR modifier interferon alpha (IFNalpha), PKR was additionally upregulated and both PKR activation and apoptosis were increased. Subcutaneous xenograft tumors were selectively targeted using an adenoviral vector expressing
E2F-1
under the control of the human telomerase reverse transcriptase (hTERT) promoter (AdhTERT-E2F). Weekly systemic administration of AdhTERT-E2F inhibited tumor growth. The tumor suppressive effect of AdhTERT-E2F therapy was further enhanced in combination with IFNalpha.Our results demonstrate that PKR activating agents enhance the anti-tumor effect of
E2F-1
overexpression in HCC in-vitro and in-vivo. Hence, modulation of PKR is a potential strategy to increase the efficacy of PKR-dependent anti-tumor therapies.
...
PMID:Dual induction of PKR with E2F-1 and IFN-alpha to enhance gene therapy against hepatocellular carcinoma. 1853 17
<< Previous
1
2
3
4
5
6
7
Next >>