Gene/Protein
Disease
Symptom
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Enzyme
Compound
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)
The development of IDDM results from the destruction of pancreatic beta cells. Genetic factors, various immune system alterations, and environmental factors have been studied as the possible causes of IDDM. The concordance rate for developing IDDM between monozygotic twins approaches 50%, suggesting that genetic factors are necessary, but nongenetic factors such as various immune system alterations and environmental factors also influence the clinical expression of genetic susceptibility. Environmental factors (e.g., viruses, chemicals, and diet) affecting the induction of diabetes may act as primary injurious agents which damage pancreatic beta cells or as triggering agents of autoimmunity. Certain viruses including EMC-D and Mengo virus 2T can directly infect pancreatic beta cells and replicate in the cells. The replication of viruses in the beta cells results in the destruction of the cells within 3 days, and the infected mice develop a diabeteslike syndrome in 3-4 days without the involvement of autoimmunity. In contrast, rubella virus appears to be somewhat weakly associated with autoimmune IDDM in hamsters. In addition, endogenous retrovirus expressed in pancreatic beta cells is clearly associated with the development of insulitis and diabetes in
NOD
mice. In man, there appears to be no correlation between the detection of islet cell autoantibodies and anti-Coxsackie B viral antibodies in newly diagnosed IDDM. In contrast, persistent infection of CMV and rubella virus appears to be associated with the presence of autoantibodies in newly diagnosed IDDM patients. It is particularly noteworthy that human CMV can induce islet cell autoantibodies that react specifically with a 38 kDa islet cell protein which may represent islet cell-specific antigens in a proportion of CMV-associated IDDM cases. These observations suggest that the association of diabetes with Coxsackie B viruses might be due to cytolytic infection of the beta cells with no link to autoimmunity, while both rubella virus and CMV are probably associated with autoimmune IDDM. A number of structurally diverse chemicals including alloxan, streptozotocin, chlorozotocin, Vacor, and cyproheptadine are diabetogenic mainly in rodents and sometimes in man. Possible mechanisms for beta cell destruction by these chemicals include (a) generation of oxygen free radicals and alteration of endogenous scavengers of these reactive species; (b) breakage of DNA and a consequent increase in the activity of poly-ADP-ribose synthetase, an enzyme depleting nicotinamide adenine dinucleotide in beta cells; and (c) inhibition of active calcium transport and calmodulin-activated
protein kinase
activity. (ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:The role of viruses and environmental factors in the induction of diabetes. 207 86
It is well accepted that the Bcr-Abl oncoprotein encoded by the Philadelphia chromosome is responsible for causing chronic myelogenous leukemia (CML). We have previously demonstrated that expression of Bcr interferes with the oncogenic effects of Bcr-Abl. To examine the effects of increased Bcr expression on Bcr-Abl oncogenic effects in a more physiological system, we tested the leukemogenic potential of a clone of K562 cells (K6 K562) containing an inducible BCR gene in
NOD
/scid mice. In this clone, the BCR gene was placed under the control of a tetracycline (Tet) repression system with a cytomegalovirus (CMV) promoter. Induction of exogenous Bcr protein by removal of Tet from the culture medium caused a dramatic increase in Bcr
serine kinase
activity, yielding predominantly phosphoserine Bcr, despite the presence of Bcr-Abl in the kinase reaction mixture. Prior to induction, the endogenous Bcr was predominantly in the phosphotyrosine form because of phosphorylation by Bcr-Abl, which we previously have shown suppresses Bcr serine/threonine kinase activity. Injection of K6 K562 cells into
NOD
/scid mice under conditions where BCR expression was suppressed resulted in death or terminal illness in 100% of the mice within 35 days after injection. These mice had a severe wasting syndrome characterized by atrophy of bone marrow hematopoiesis, and/or neoplasia of liver, bone marrow and spleen. Neoplastic spleens from these mice usually contained b3a2 Bcr-Abl transcripts. In contrast, induction of BCR expression at the time of injection allowed 80% survival; these healthy mice had no detectable microscopic lesions in blood forming organs. This difference in survival was significant with P<0.0001. Of interest, mice that were fed Tet for 19 days to initiate the disease syndrome and then released from the BCR transcriptional block had a significantly better survival pattern than mice exposed to Tet throughout the entire period. Moreover, 30% of these mice (three mice) survived through day 50. We conclude from these findings that BCR gene expression strongly inhibits the oncogenic effects of Bcr-Abl in
NOD
/scid mice, yielding healthy mice in most cases.
...
PMID:BCR gene expression blocks Bcr-Abl induced pathogenicity in a mouse model. 1131 35
Ulcerative colitis and Crohn's disease are the two entities of chronic inflammatory bowel diseases (IBD). One of the main pathogenic mechanisms is probably a dysregulated immune response triggered by products of the enteric bacterial flora. The goal of this study was to evaluate the effects of the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 on inflammatory responses using the DSS-induced experimental colitis model in mice reflecting human IBD. We found that SB203580 improved the clinical score, ameliorates the histological alterations, and reduces the mRNA levels of proinflammatory cytokines. In addition to p38 kinase activity, the "classical" and the "alternative" NF-kappaB pathways were also strongly activated during colitis induction. All three pathways were drastically down-regulated by SB203580 treatment. An analysis of the molecular basis of NF-kappaB activation revealed that Rip-like interacting caspase-like apoptosis-regulatory
protein kinase
(RICK), a key component of a pathway leading to NF-kappaB induction, is also strongly inhibited by SB203580. Since RICK is an effector kinase of NOD2, an intracellular receptor of bacterial peptidoglycan, these results support the notion that
NOD
signaling could play a pivotal role in the IBD pathogenesis. Thus, RICK could represent a novel target for future therapies in human IBD.
...
PMID:Inhibition of p38 MAP kinase- and RICK/NF-kappaB-signaling suppresses inflammatory bowel disease. 1528 40
Nuclear factor-kappaB (NF-kappaB) is the main target of anti-inflammatory therapies in human chronic inflammatory bowel diseases (IBD), Crohn disease, and ulcerative colitis. This study investigates the molecular anti-inflammatory mechanisms of SB203580, an inhibitor of the mitogen-activated protein kinase p38. The murine trinitrobenzene sulfonic acid (TNBS)-induced colitis was used as an established model of human Crohn disease. Here we show that SB203580 improved the clinical condition, reduced intestinal inflammation, and suppressed mRNA levels of pro-inflammatory cytokines elevated upon induction of colitis. Besides p38 kinase activity, the "classical" IkappaB-dependent NF-kappaB pathway was strongly up-regulated during colitis induction, whereas the "alternative" was not. SB203580 treatment resulted in a drastic down-regulation of p38 and NF-kappaB activity. The molecular analysis of NF-kappaB activation revealed that Rip-like interacting caspase-like apoptosis-regulatory
protein kinase
(RICK), a key component of a pathway leading to NF-kappaB induction, is also strongly inhibited by SB203580. In contrast, SB203580 had no effect on the colitis-induced activation of other potential NF-kappaB-activating kinases such as protein kinase C (PKC), mixed lineage kinase 3, and the oncogene product Cot/TPL2. Thus, the inhibitory effect of SB203580 on NF-kappaB activation is to a large extent mediated by RICK inhibition. RICK is the effector kinase of the intracellular receptor of bacterial peptidoglycan
NOD
. Because bacterial products are suggested to be the key pathogenic agents triggering IBD, inhibition of the
NOD
/RICK pathway may serve as a novel target of future therapies in human IBD.
...
PMID:Inhibition of RICK/nuclear factor-kappaB and p38 signaling attenuates the inflammatory response in a murine model of Crohn disease. 1569 43
The CATERPILLER (CLR, also
NOD
and NLR) proteins share structural similarities with the nucleotide binding domain (NBD)-leucine-rich repeat (LRR) superfamily of plant disease-resistance (R) proteins and are emerging as important immune regulators in animals. CLR proteins contain NBD-LRR motifs and are linked to a limited number of distinct N-terminal domains including transactivation, CARD (caspase activation and recruitment), and pyrin domains (PyD). The CLR gene, Monarch-1/Pypaf7, is expressed by resting primary myeloid/monocytic cells, and its expression in these cells is reduced by Toll-like receptor (TLR) agonists tumor necrosis factor (TNF) alpha and Mycobacterium tuberculosis. Monarch-1 reduces NFkappaB activation by TLR-signaling molecules MyD88, IRAK-1 (type I interleukin-1 receptor-associated
protein kinase
), and TRAF6 (TNF receptor (TNFR)-associated factor) as well as TNFR signaling molecules TRAF2 and RIP1 but not the downstream NFkappaB subunit p65. This indicates that Monarch-1 is a negative regulator of both TLR and TNFR pathways. Reducing Monarch-1 expression with small interference RNA in myeloid/monocytic cells caused a dramatic increase in NFkappaB activation and cytokine expression in response to TLR2/TLR4 agonists, TNFalpha, or M. tuberculosis infection, suggesting that Monarch-1 is a negative regulator of inflammation. Because Monarch-1 is the first CLR protein that interferes with both TLR2 and TLR4 activation, the mechanism of this interference is significant. We find that Monarch-1 associates with IRAK-1 but not MyD88, resulting in the blockage of IRAK-1 hyperphosphorylation. Mutants containing the NBD-LRR or PyD-NBD also blocked IRAK-1 activation. This is the first example of a CLR protein that antagonizes inflammatory responses initiated by TLR agonists via interference with IRAK-1 activation.
...
PMID:The CATERPILLER protein monarch-1 is an antagonist of toll-like receptor-, tumor necrosis factor alpha-, and Mycobacterium tuberculosis-induced pro-inflammatory signals. 1620 35
Micro-RNAs (miRNAs) are one class of small non-coding RNAs that have important regulatory roles in higher plants. Much less is known about their prevalence and function in lower land plants. Previously we cloned 100 non-structural small RNAs from the moss Physcomitrella patens but could annotate only 11 as miRNAs. To identify additional moss miRNAs among cloned small RNAs we have analyzed their genomic sequences for a characteristic miRNA precursor-like structure. This analysis revealed 19 new moss miRNAs that are predicted to be encoded by 22 putative foldbacks. Northern blot analysis confirmed the expression of 14 new miRNA representatives. Half of these were gametophore specific, the rest were detected at low levels in the protonema. We predicted 12 genes as targets of nine new miRNAs. Three of these show homology to transcription factors and the others appear to play roles in diverse physiological processes including light and cytokine signaling, which have not to date been shown to be regulated by a miRNA in flowering plants. Four target genes, which show homology to
ATN1
-like
protein kinase
, NAC transcription factors and a cytokinin receptor, have been validated by miRNA-mediated mRNA cleavage. In addition, our analysis revealed that seven small RNAs represent miRNA* and three represent intermediates of pre-miRNA processing, providing evidence for specific DICER-like cleavage steps during miRNA biogenesis in moss. Our findings suggest that miRNAs are common in mosses and set the stage for the elucidation of their varied biological functions.
...
PMID:Novel micro-RNAs and intermediates of micro-RNA biogenesis from moss. 1682 79
The rhizobial-derived signaling molecule Nod factor is essential for the establishment of the Medicago truncatula/Sinorhizobium meliloti symbiosis. Nod factor perception and signal transduction in the plant involve calcium spiking and lead to the induction of nodulation gene expression. It has previously been shown that the heterotrimeric G-protein agonist mastoparan can activate nodulation gene expression in a manner analogous to Nod factor activation of these genes and this requires DOESN'T MAKE INFECTIONS3 (DMI3), a calcium- and calmodulin-dependent
protein kinase
(CCaMK) that is required for Nod factor signaling. Here we show that mastoparan activates oscillations in cytosolic calcium similar but not identical to Nod factor-induced calcium spiking. Mastoparan-induced calcium changes occur throughout the cell, whereas Nod factor-induced changes are restricted to the region associated with the nucleus. Mastoparan-induced calcium spiking occurs in plants mutated in the receptor-like kinases
NOD
FACTOR PERCEPTION and DMI2 and in the putative cation channel DMI1, which are all required for Nod factor induction of calcium spiking, indicating either that mastoparan functions downstream of these components or that it uses an alternative mechanism to Nod factor for activation of calcium spiking. However, both mastoparan and Nod factor-induced calcium spiking are inhibited by cyclopiazonic acid and n-butanol, suggesting some common mechanisms underpinning these two calcium agonists. The fact that mastoparan and Nod factor both activate calcium spiking and can induce nodulation gene expression in a DMI3-dependent manner strongly implicates CCaMK in the perception and transduction of the calcium signal.
...
PMID:Mastoparan activates calcium spiking analogous to Nod factor-induced responses in Medicago truncatula root hair cells. 1732 38
Many extracellular stimuli regulate growth, survival, and differentiation responses through activation of the dual specificity mitogen activated
protein kinase
(MAPK) kinase three (MKK3) and its downstream effector p38 MAPK. Using CD34+ hematopoietic progenitor cells, here we describe a novel role for MKK3-p38MAPK in the regulation of myelopoiesis. Inhibition of p38MAPK utilizing the pharmacological inhibitor SB203580, enhanced neutrophil development ex vivo, but conversely reduced eosinophil differentiation. In contrast, constitutive activation of MKK3 dramatically inhibited neutrophil differentiation. Transplantation of beta2-microglobulin(-/-) nonobese diabetic/severe combined immune deficient (
NOD
/SCID) mice with CD34+ cells ectopically expressing constitutively active MKK3 resulted in reduced neutrophil differentiation in vivo, whereas eosinophil development was enhanced. Inhibitory phosphorylation of CCAAT/enhancer binding protein alpha (C/EBPalpha) on serine 21 was induced upon activation of p38MAPK. Moreover, ectopic expression of a non-phosphorylatable C/EBPalpha mutant was sufficient to abrogate MKK3-induced inhibition of neutrophil development. Furthermore, treatment of CD34+ progenitors from patients with severe congenital neutropenia with SB203580 restored neutrophil development. These results establish a novel role for MKK3-p38MAPK in the regulation of lineage choices during myelopoiesis through modulation of C/EBPalpha activity. This signaling module may thus provide an important therapeutic target in the treatment of bone marrow failure.
...
PMID:p38 MAP kinase inhibits neutrophil development through phosphorylation of C/EBPalpha on serine 21. 1954 70
An elevated level of nucleophosmin (NPM) is often found in actively proliferative cells including human tumors. To identify the regulatory role for NPM phosphorylation in proliferation and cell cycle control, a series of mutants targeting the consensus
cyclin-dependent kinase
(
CDK
) phosphorylation sites was created to mimic or abrogate either single-site or multi-site phosphorylation. Simultaneous inactivation of two
CDK
phosphorylation sites at Ser10 and Ser70 (NPM-AA) induced G(2)/M cell cycle arrest, phosphorylation of Cdk1 at Tyr15 (Cdc2(Tyr15)) and increased cytoplasmic accumulation of Cdc25C. Strikingly, stress-induced Cdk1(Tyr15) and Cdc25C sequestration was suppressed by expression of a phosphomimetic NPM mutant created on the same
CDK
sites (S10E/S70E, NPM-EE). Further analysis revealed that phosphorylation of NPM at both Ser10 and Ser70 was required for proper interaction between Cdk1 and Cdc25C. Moreover, NPM-EE directly bound to Cdc25C and prevented phosphorylation of Cdc25C at Ser216 during mitosis. Finally, NPM-EE overrided stress-induced G(2)/M arrest and increased leukemia blasts in a
NOD
/SCID xenograft model. Thus, these findings reveal a novel function of NPM on regulation of cell cycle progression, in which phosphorylation of NPM controls cell cycle progression at G(2)/M transition through modulation of Cdk1 and Cdc25C activities.
...
PMID:NPM phosphorylation stimulates Cdk1, overrides G2/M checkpoint and increases leukemic blasts in mice. 1993 6
Insulin-like growth factor binding protein 7 (IGFBP7) has been shown to be a tumor suppressor in a variety of cancers. We previously have shown that IGFBP7 expression is inversely correlated with disease progression and poor outcome in breast cancer. Overexpression of IGFBP7 in MDA-MB-468, a triple-negative breast cancer (TNBC) cell line, resulted in inhibition of growth and migration. Xenografted tumors bearing ectopic IGFBP7 expression were significantly growth-impaired compared to IGFBP7-negative controls, which suggested that IGFBP7 treatment could inhibit breast cancer cell growth. To confirm this notion, 14 human patient primary breast tumors were analyzed by qRTPCR for IGFBP7 expression. The TNBC tumors expressed the lowest levels of IGFBP7 expression, which also correlated with higher tumorigenicity in mice. Furthermore, when breast cancer cell lines were treated with IGFBP7, only the TNBC cell lines were growth inhibited. Treatment of
NOD
/SCID mice harboring xenografts of TNBC cells with IGFBP7 systemically every 3-4 days inhibited tumorigenesis, with associated anti-angiogenic effects, together with increased apoptosis. Upon examining the mechanism of IGFBP7-mediated growth inhibition in TNBC cells, we found that cells not only were arrested in G1 phase of the cell cycle but also underwent senescence as a result of treatment with IGFBP7. Interestingly, IGFBP7 treatment was also associated with strong activation of the stress-associated p38 MAPK pathway, together with upregulation of p53 and the cyclin-dependent
protein kinase
(CDK) inhibitor, p21(cip1). Prolonged treatment of cells with IGFBP7 resulted in increased cell death, marked by an increase in apoptotic cells and associated cleaved PARP. This is the first study showing that exogenous IGFBP7 inhibits TNBC cell growth both in vitro and in vivo. Taken together, these results suggest IGFBP7 treatment might have therapeutic potential for TNBC.
...
PMID:IGFBP7 reduces breast tumor growth by induction of senescence and apoptosis pathways. 2199 38
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