Gene/Protein
Disease
Symptom
Drug
Enzyme
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Pivot Concepts:
Gene/Protein
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Target Concepts:
Gene/Protein
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Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Regulation, recognition and cell signaling involve the coordinated actions of many players. To achieve this coordination, each participant must have a valid identification (ID) that is easily recognized by the others. For proteins, these IDs are often within intrinsically disordered (also ID) regions. The functions of a set of well-characterized ID regions from a diversity of proteins are presented herein to support this view. These examples include both more recently described signaling proteins, such as p53, alpha-synuclein, HMGA, the Rieske protein, estrogen receptor alpha, chaperones, GCN4, Arf, Hdm2, FlgM, measles virus nucleoprotein, RNase E,
glycogen synthase kinase
3beta, p21(Waf1/Cip1/Sdi1), caldesmon, calmodulin,
BRCA1
and several other intriguing proteins, as well as historical prototypes for signaling, regulation, control and molecular recognition, such as the lac repressor, the voltage gated potassium channel, RNA polymerase and the S15 peptide associating with the RNA polymerase S-protein. The frequent occurrence and the common use of ID regions in important protein functions raise the possibility that the relationship between amino acid sequence, disordered ensemble and function might be the dominant paradigm for the molecular recognition that serves as the basis for signaling and regulation by protein molecules.
...
PMID:Showing your ID: intrinsic disorder as an ID for recognition, regulation and cell signaling. 1609 5
Fanconi anemia (FA), a rare inherited disorder, exhibits a complex phenotype including progressive bone marrow failure, congenital malformations and increased risk of cancers, mainly acute myeloid leukaemia. At the cellular level, FA is characterized by hypersensitivity to DNA cross-linking agents and by high frequencies of induced chromosomal aberrations, a property used for diagnosis. FA results from mutations in one of the eleven FANC (FANCA to FANCJ) genes. Nine of them have been identified. In addition, FANCD1 gene has been shown to be identical to BRCA2, one of the two breast cancer susceptibility genes. Seven of the FANC proteins form a complex, which exists in four different forms depending of its subcellular localisation. Four FANC proteins (D1(BRCA2), D2, I and J) are not associated to the complex. The presence of the nuclear form of the FA core complex is necessary for the mono-ubiquitinylation of FANCD2 protein, a modification required for its re-localization to nuclear foci, likely to be sites of DNA repair. A clue towards understanding the molecular function of the FANC genes comes from the recently identified connection of FANC to the
BRCA1
, ATM, NBS1 and ATR genes. Two of the FANC proteins (A and D2) directly interact with
BRCA1
, which in turn interacts with the MRE11/RAD50/NBS1 complex, which is one of the key components in the mechanisms involved in the cellular response to DNA double strand breaks (DSB). Moreover, ATM, a
protein kinase
that plays a central role in the network of DSB signalling, phosphorylates in vitro and in vivo FANCD2 in response to ionising radiations. Moreover, the NBS1 protein and the monoubiquitinated form of FANCD2 seem to act together in response to DNA crosslinking agents. Taken together with the previously reported impaired DSB and DNA interstrand crosslinks repair in FA cells, the connection of FANC genes to the ATM, ATR, NBS1 and
BRCA1
links the FANC genes function to the finely orchestrated network involved in the sensing, signalling and repair of DNA replication-blocking lesions.
...
PMID:[Fanconi anemia: genes and function(s) revisited]. 1611 58
The A-kinase anchor protein 13 (AKAP13, alias BRX and lbc) tethers
cAMP-dependent protein kinase
to its subcellular environment and catalyses Rho GTPases activity as a guanine nucleotide exchange factor. The crucial role of members of the Rho family of GTPases in carcinogenesis is well established and targeting Rho proteins with antineoplastic compounds has become a major effort in the fight against cancer. Thus, genetic alterations within the candidate cancer susceptibility gene AKAP13 would be expected to provoke a constitutive Rho signalling, thereby facilitating the development of cancer. Here, we analysed the potential impact of four polymorphic non-conservative amino acid exchanges (Arg494Trp, Lys526Gln, Asn1086Asp and Gly2461Ser) in AKAP13 on familial breast cancer. We performed a case-control study using genomic DNA of
BRCA1
/2 mutation-negative German female index patients from 601 unrelated families, among a subset of 356 high-risk families, and 1053 German female unrelated controls. The newfound Lys526Gln polymorphism revealed a significant association with familial breast cancer (OR = 1.58, 95% CI = 1.07-2.35) and an even stronger association with high-risk familial breast cancer (OR = 1.85, 95% CI = 1.19-2.88). Haplotype analyses were in line with genotype results displaying a similar significance as analyses of individual polymorphisms. Due to the pivotal role of AKAP13 in the Rho GTPases signalling network, this variant might affect the susceptibility to other cancers as well.
...
PMID:Association of genetic variants in the Rho guanine nucleotide exchange factor AKAP13 with familial breast cancer. 1623 58
RTT107 (ESC4, YHR154W) encodes a
BRCA1
C-terminal-domain protein that is important for recovery from DNA damage during S phase. Rtt107 is a substrate of the checkpoint
protein kinase
Mec1, although the mechanism by which Rtt107 is targeted by Mec1 after checkpoint activation is currently unclear. Slx4, a component of the Slx1-Slx4 structure-specific nuclease, formed a complex with Rtt107. Deletion of SLX4 conferred many of the same DNA-repair defects observed in rtt107delta, including DNA damage sensitivity, prolonged DNA damage checkpoint activation, and increased spontaneous DNA damage. These phenotypes were not shared by the Slx4 binding partner Slx1, suggesting that the functions of the Slx4 and Slx1 proteins in the DNA damage response were not identical. Of particular interest, Slx4, but not Slx1, was required for phosphorylation of Rtt107 by Mec1 in vivo, indicating that Slx4 was a mediator of DNA damage-dependent phosphorylation of the checkpoint effector Rtt107. We propose that Slx4 has roles in the DNA damage response that are distinct from the function of Slx1-Slx4 in maintaining rDNA structure and that Slx4-dependent phosphorylation of Rtt107 by Mec1 is critical for replication restart after alkylation damage.
...
PMID:Slx4 regulates DNA damage checkpoint-dependent phosphorylation of the BRCT domain protein Rtt107/Esc4. 1626 68
BRCA1
germline mutations predispose women to early onset, familial breast and ovarian cancer.
BRCA1
has been recently implicated in the cellular response to agents that disrupt the mitotic spindle. In this report, we studied
BRCA1
contribution to paclitaxel response in MCF-7 breast cancer cells. We show that MCF-7 cells transfected with
BRCA1
siRNA display a significant increase in resistance to paclitaxel compared with the control cells. We next demonstrate that downregulation of
BRCA1
reduces the mitotic index and triggers premature cyclin B1 degradation and decrease in Cdk1 activity following paclitaxel treatment, suggesting that
BRCA1
downregulation results in precocious inactivation of the spindle checkpoint. These findings were confirmed by showing that
BRCA1
downregulation induces premature sister-chromatids separation in MCF-7 cells following spindle damage. Furthermore, we show that
BRCA1
up-regulates the expression of the
protein kinase
BubR1, essential component of the functional spindle checkpoint, whose downregulation is known to result in paclitaxel resistance in MCF-7 cells. Altogether, our findings support the notion that downregulation of
BRCA1
expression mediates paclitaxel resistance through premature inactivation of spindle checkpoint in MCF-7 breast cancer cells. They link
BRCA1
to the mitotic checkpoint that plays an essential role in the maintenance of chromosomal stability.
...
PMID:BRCA1 downregulation leads to premature inactivation of spindle checkpoint and confers paclitaxel resistance. 1663 80
Centrosome stability is required for successful mitosis in mammalian cells. Amplification of the centrosome leads to chromosomal missegregation and generation of aneuploidy, which are closely associated with cell transformation and tumorigenesis (Doxsey, S. J. (2001) Nat. Cell Biol. 3, E105-E108; Hinchcliffe, E. H., and Sluder, G. (2001) Genes Dev. 15, 1167-1181; Pihan, G. A., Purohit, A., Wallace, J., Malhotra, R., Liotta, L., and Doxsey, S. J. (2001) Cancer Res. 61, 2212-2219). However, there are currently limited insights into mechanism(s) for this critical biological event. Here we show that Gadd45a, a DNA damage-inducible protein that is regulated by tumor suppressors p53 and
BRCA1
, participates in the maintenance of centrosome stability. Mouse embryonic fibroblasts derived from gadd45a knock-out mice exhibit centrosome amplification (designated as increased centrosome numbers). Introduction of exogenous Gadd45a into mouse embryonic fibroblasts isolated from gadd45a-null mice substantially restored the normal centrosome profile. In contrast to p21(waf1/cip1), which ensures coordinated initiation of centrosome, Gadd45a had no significant effect on centrosome duplication in S phase. Interestingly Gadd45a was found to physically associate with Aurora-A
protein kinase
, whose deregulated expression results in centrosome abnormality. Furthermore Gadd45a was demonstrated to strongly inhibit Aurora-A kinase activity and to antagonize Aurora-A-induced centrosome amplification. These findings identify a novel mechanism for Gadd45a in the maintenance of centrosome stability and broaden understandings of p53- and
BRCA1
-regulated signaling pathways in maintaining genomic fidelity.
...
PMID:Gadd45a interacts with aurora-A and inhibits its kinase activity. 1677 93
Many of the insights that we have gained into the mechanisms involved in cellular DNA damage response pathways have come from studies of human cancer susceptibility syndromes that are altered in DNA damage responses. ATM, the gene mutated in the disorder, ataxia-telangiectasia, is a
protein kinase
that is a central mediator of responses to DNA double-strand breaks in cells. Recent studies have elucidated the mechanism by which DNA damage activates the ATM kinase and initiates these critical cellular signaling pathways. The SMC1 protein appears to be a particularly important target of the ATM kinase, playing critical roles in controlling DNA replication forks and DNA repair after the damage. A major role for the NBS1 and
BRCA1
proteins appears to be in the recruitment of an activated ATM kinase molecule to the sites of DNA breaks so that ATM can phosphorylate SMC1. Generation of mice and cells that are unable to phosphorylate SMC1 demonstrated the importance of SMC1 phosphorylation in the DNA-damage-induced S-phase checkpoint, in determining rates of repair of chromosomal breaks, and in determining cell survival after DNA damage. Focusing on ATM and SMC1, the molecular controls of these pathways is discussed.
...
PMID:The ATM-dependent DNA damage signaling pathway. 1686 43
Abnormal regulation of progression from G(1) to S phase of the cell cycle by altered activity of cyclin-dependent kinases (CDKs) is a hallmark of cancer. However, inhibition of CDKs, particularly CDK2, has not shown selective activity against most cancer cells because the kinase seems to be redundant in control of cell cycle progression. Here, we show a novel role in the DNA damage response and application of
CDK
inhibitors in checkpoint-deficient cells. CDK2(-/-) mouse fibroblasts and small interfering RNA--mediated or small-molecule--mediated CDK2 inhibition in MCF7 or U2OS cells lead to delayed damage signaling through Chk1, p53, and Rad51. This coincided with reduced DNA repair using the single-cell comet assay and defects observed in both homologous recombination and nonhomologous end-joining in cell-based assays. Furthermore, tumor cells lacking cancer predisposition genes
BRCA1
or ATM are 2- to 4-fold more sensitive to
CDK
inhibitors. These data suggest that inhibitors of CDK2 can be applied to selectively enhance responses of cancer cells to DNA-damaging agents, such as cytotoxic chemotherapy and radiotherapy. Moreover, inhibitors of CDKs may be useful therapeutics in cancers with defects in DNA repair, such as mutations in the familial breast cancer gene
BRCA1
.
...
PMID:Cyclin-dependent kinase 2 functions in normal DNA repair and is a therapeutic target in BRCA1-deficient cancers. 1691 1
Overexpression of
cAMP-dependent protein kinase A
(
PKA
) is a hallmark of the great majority of human cancers including breast cancer.
A-kinase
anchoring proteins (AKAPs) coordinate the specificity of
PKA
signalling by localizing the kinase to its subcellular sites. We tested the hypothesis whether the functional amino acid exchange Ile646Val, located in the kinase-binding domain of AKAP10, is a low-penetrance familial breast cancer risk factor. Ile646Val alters the binding of AKAP10 to
PKA
and is associated with morbidity. The analysis of 787
BRCA1
/2 mutation-negative familial breast cancer patients and 993 controls revealed an association of the AKAP10 Ile646Val polymorphism with increased familial breast cancer risk [odds ratio (OR)=1.25, 95% confidence interval (CI) 1.03-1.51, P=0.024]. Our previous study has shown that AKAP13 Lys526Gln is associated with familial breast cancer (OR=1.58). Here, we discovered that carriers of both variants, AKAP10 Ile646Val and AKAP13 Lys526Gln, are at a further enhanced breast cancer risk (OR=2.41, 95% CI 1.30-4.46, P=0.005).
PKA
is a major target of therapeutic anticancer strategies. Phosphorylation of the estrogen receptor (ER) alpha by
PKA
induces resistance against the anti-estrogen tamoxifen. Our results indicate for the first time the importance of AKAP10 Ile646Val for familial breast cancer susceptibility. Due to the impact of Ile646Val on the subcellular localization of
PKA
, it will be interesting to investigate whether this polymorphism influences the effectiveness of
PKA
and tamoxifen based therapeutic anticancer concepts.
...
PMID:The functional genetic variant Ile646Val located in the kinase binding domain of the A-kinase anchoring protein 10 is associated with familial breast cancer. 1695 8
Increased copy number involving chromosome 3q26 is a frequent and early event in cancers of the ovary, lung, head and neck, cervix, and
BRCA1
positive and basal breast cancers. The p110alpha catalytic subunit of phosphoinositide-3-kinase (PI3KCA) and
protein kinase
Ciota (PKCiota) have previously been shown as functionally deregulated by 3q copy number increase. High-resolution array comparative genomic hybridization of 235 high-grade serous epithelial ovarian cancers using contiguous bacterial artificial chromosomes across 3q26 delineated an approximately 2 Mb-wide region at 3q26.2 encompassing PDCD10 to MYNN (chr3:168722613-170908630). Ecotropic viral integration site-1 (EVI1) and myelodysplastic syndrome 1 (MDS1) are located at the center of this region, and their DNA copy number increases are associated with at least 5-fold increased RNA transcript levels in 83% and 98% of advanced ovarian cancers, respectively. Moreover, MDS1/EVI1 and EVI1 protein levels are increased in ovarian cancers and cancer cell lines. EVI1 and MDS1/EVI1 gene products increased cell proliferation, migration, and decreased transforming growth factor-beta-mediated plasminogen activator inhibitor-1 promoter activity in ovarian epithelial cells. Intriguingly, the increases in EVI1 DNA copy number and MDS1/EVI1 transcripts are associated with improved patient outcomes, whereas EVI1 transcript levels are associated with a poor patient survival. Thus, the favorable patient prognosis associated with increased DNA copy number seems to be as a result of high-level expression of the fusion transcript MDS1/EVI1. Collectively, these studies suggest that MDS1/EVI1 and EVI1, previously implicated in acute myelogenous leukemia, contribute to the pathophysiology of epithelial ovarian cancer.
...
PMID:Amplification of MDS1/EVI1 and EVI1, located in the 3q26.2 amplicon, is associated with favorable patient prognosis in ovarian cancer. 1740 14
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