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Symptom
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Enzyme
Compound
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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
DNA-protein crosslinking by cis-dichlorodiammineplatinum (II) (cis-
DDP
) was applied to study chromatin structure in situ. Histone H1 (H5) is crosslinked to DNA in significant amounts whereas core histones remain practically unattached. "Protein image hybridization" experiments show that the 5'-region of the D metanogaster hsp 70 gene is free of histone H1 in both control nuclei and nuclei isolated from heat-shocked embryos.
Biochem
Mol
Biol Int 1996 Apr
PMID:Mapping protein-DNA interactions with CIS-DDP: chromatin structure of promoter region of D. Melanogaster hsp 70 gene. 913 69
An affinity gel matrix containing an enzyme (DD-peptidase) with specific beta-lactam binding properties was characterized with respect to its binding and reactivity behavior with penicillin. The data show that immobilization of
DDP
by reaction with the enzymes susceptible amino groups resulted in changes in catalytic activity on a tripeptide substrate, penicillin binding efficiency and pH stability of drug binding. Properties unaffected by immobilization were the drug-enzyme complex stability, binding reaction mechanism, drug selectivity and method of complex desorption. The affinity of
DDP
for penicillin-G was investigated by surface plasmon resonance. These characteristics were compared with those of the soluble enzyme. Conditions for elution of the bound drug were determined and a method for immobilizing Streptomyces
DDP
by which its binding site structure is sustained was also evaluated.
J
Mol
Recognit
PMID:Effect of immobilization on the penicillin binding and reactivity properties of DD-peptidase from Streptomyces R61. 917 61
We present data demonstrating that the cytotoxic compound [Pt2Cl4(diminazene aceturate)2]Cl4.4H2O (Pt-berenil) circumvents cisplatin resistance in ovarian carcinoma cells. The analysis of the interaction of Pt-berenil with linear and supercoiled DNA indicates that this compound induces the formation of a large number of covalent interstrand cross-links on DNA and that this number is significantly higher than that produced by cis-diamminedichloroplatinum(II) (cis-
DDP
). Renaturation experiments, interstrand cross-link assays, and electron microscopy indicate that the kinetics of DNA interstrand cross-link formation caused by Pt-berenil binding is faster than that caused by cis-
DDP
at similar levels of platinum bound to DNA. Furthermore, the number of DNA interstrand cross-links in Pt-berenil-DNA complexes is influenced by supercoiling. Circular dichroism experiments show that Pt-berenil strongly inhibits the B-DNA-to-Z-DNA transition of poly(dG-m5 dC). poly(dG-m5dC) at salt concentrations (3 mM MgCl2) at which the native methylated polynucleotide readily adopts the Z-DNA conformation, which suggests that the induction of interstrand cross-links by Pt-berenil inhibits the Z-DNA transition. On the basis of these results, we propose that bis(platinum) compounds with structure similar to Pt-berenil may act as blockers of DNA conformational changes and may also display activity in cisplatin-resistant cells.
Mol
Pharmacol 1999 Apr
PMID:The formation of DNA interstrand cross-links by a novel bis-[Pt2Cl4(diminazene aceturate)2]Cl4.4H2O complex inhibits the B to Z transition. 1010 Oct 36
The alkaline comet assay is a sensitive test for the detection of a variety of DNA lesions. However, crosslinks are not readily detected under standard test conditions. Recently, modifications have been introduced measuring crosslinks by determining the reduction of induced DNA migration. We used the comet assay to comparatively investigate in V79 cells the effect of three different crosslinkers: formaldehyde (FA), which predominantly induces DNA-protein crosslinks, cisplatin (
DDP
), which mainly produces DNA-DNA-intrastrand crosslinks, and mitomycin C (MMC), which mainly leads to DNA-DNA-interstrand crosslinks. In the standard alkaline comet assay, only MMC induced a slight increase in DNA migration at high toxic concentrations. FA and
DDP
did not induce any DNA migration under the test conditions used. In the modified comet assay, all three crosslinkers led to a clear reduction of gamma-ray-induced DNA migration. This reduction was seen in the case of FA parallel to the induction of cytotoxicity and SCE, while for MMC and
DDP
induction of cytotoxicity, SCE and HPRT gene mutations occurred at much lower concentrations than the effects in the comet assay. The DNA-DNA crosslinkers caused a reduction of induced DNA migration only at cytotoxic concentrations. Our results indicate that the modified comet assay protocol is a sensitive test for the detection of DNA-protein crosslinks. However, the results for MMC and
DDP
suggest that the modified protocol is not well suited for the evaluation of DNA-DNA crosslinkers. Furthermore, the relationship between crosslinking and genotoxicity seems to be very different for the three different types of crosslinking substances.
Environ
Mol
Mutagen 1999
PMID:Detection of crosslinks with the comet assay in relationship to genotoxicity and cytotoxicity. 1021 71
The peripheral myelin protein 22 (PMP22) and the epithelial membrane proteins (EMP-1, -2, and -3) comprise a subfamily of small hydrophobic membrane proteins. The putative four-transmembrane domain structure as well as the genomic structure are highly conserved among family members. PMP22 and EMPs are expressed in many tissues, and functions in cell growth, differentiation, and apoptosis have been reported. EMP-1 is highly up-regulated during squamous differentiation and in certain tumors, and a role in tumorigenesis has been proposed. PMP22 is most highly expressed in peripheral nerves, where it is localized in the compact portion of myelin. It plays a crucial role in normal physiological and pathological processes in the peripheral nervous system. Progress in molecular genetics has revealed that genetic alterations in the PMP22 gene, including duplications, deletions, and point mutations, are responsible for several forms of hereditary peripheral neuropathies, including Charcot-Marie-Tooth disease type 1A (CMT1A), Dejerine-Sottas syndrome (
DDS
), and hereditary neuropathy with liability to pressure palsies (HNPP). The natural mouse mutants Trembler and Trembler-J contain a missense mutation in different hydrophobic domains of PMP22, resulting in demyelination and Schwann cell proliferation. Transgenic mice carrying many copies of the PMP22 gene and PMP22-null mice display a variety of defects in the initial steps of myelination and/or maintenance of myelination, whereas no pathological alterations are detected in other tissues normally expressing PMP22. Further characterization of the interactions of PMP22 and EMPs with other proteins as well as their regulation will provide additional insight into their normal physiological function and their roles in disease and possibly will result in the development of therapeutic tools.
Prog Nucleic Acid Res
Mol
Biol 2000
PMID:The peripheral myelin protein 22 and epithelial membrane protein family. 1069 8
Several laboratories have attempted with little success to induce Fas-mediated apoptosis in prostate cancer (PCa) cells, using different external Fas agonists, i.e., anti-Fas antibodies and membrane-bound FasL. The present study confirms these earlier results using the anti-Fas antibody CH-11 in five human PCa cell lines (PPC-1, LNCaP, PC-3, TSU-Pr1, and DU145). However, intracellular murine FasL expression induced Fas-mediated apoptosis in all CH-11-resistant cell lines. Adenovirus (AdGFPFasL(TET)) was used to deliver a Murine FasL-GFP fusion gene into human PCa cells resulting in 70-98% apoptosis at 48 h as determined by the
MTS
assay. DU145 and PPC-1 cells treated with AdGFPFasL(TET) stained positive for the TUNEL assay, indicating that cell death was via apoptosis. Using immunofluorescent microscopy, Fas and GFPFasL colocalized to the same intracellular compartment. The anti-Fas neutralizing antibody ZB-4 was unable to block AdGFPFasL(TET)-mediated cell death, suggesting that intracellular FasL may ligate Fas within the Golgi and/or endoplasmic reticulum. This is the first evidence suggesting that these two molecules interact prior to cell surface presentation. Collectively, these findings indicate that intracellular GFPFasL expression is superior to CH-11 at inducing Fas-mediated apoptosis in human PCa cells and may allow use of AdGFPFasL(TET) for PCa gene therapy.
Mol
Ther 2000 Oct
PMID:Intracellular Fas ligand expression causes Fas-mediated apoptosis in human prostate cancer cells resistant to monoclonal antibody-induced apoptosis. 1102 Mar 50
Recent studies have shown that caspases, which are cystein proteases, elevate endonuclease activity and induce apoptosis. Caspase-1, an interleukin-1beta converting enzyme, has been reported to be related with anti-cancer drug induced apoptosis as well as with caspase-3. To elucidate the caspase-1 activity, which might be a predictor for the effect of chemotherapy, we examined the changes of caspase-1 activity induced after exposure to cisplatin (CDDP) in six gastric cancer cell lines. A high correlation between the 50% inhibitory concentration (IC50) and caspase-1 activity ratio was shown (r=0.83, p=0.041) (caspase-1 activity ratio: the caspase-1 activity of cells at 4 h after CDDP treatment/the caspase-1 activity of untreated cells). Further, we examined the correlation between caspase-1 activity and apoptosis induced by CDDP in two cell lines that have very different CDDP sensitivities; OCUM-2M and OCUM-2M/
DDP
(IC50; 0. 85+/-0.4 microg/ml and 9.0+/-1.2 microg/ml, respectively). The apoptotic index of OCUM-2M was significantly higher than that of OCUM-2M/
DDP
(19.8+/-3.8% vs. 4.5+/-1.2%, respectively; p=0.0005). In both cell lines, caspase-1 activity began to increase immediately after exposure to CDDP and peaked at approximately 4 h after cessation of exposure to CDDP, and gradually decreased thereafter. The caspase-1 activity of OCUM-2M was approximately 1.8-times higher than that of OCUM-2M/
DDP
at 4 h after exposure to CDDP. Taken together, our results indicate that evaluating the changes of caspase-1 activity after exposure to CDDP may be useful to predict apoptosis following CDDP treatment in gastric cancer cells.
Int J
Mol
Med 2000 Nov
PMID:Caspase-1 activity as a possible predictor of apoptosis induced by cisplatin in gastric cancer cells. 1102 23
Membrane-impermeant quaternary amine local anesthetics QX314 and QX222 can access their binding site on the cytoplasmic side of the selectivity filter from the outside in native cardiac Na(+) channels. Mutation of domain IV S6 Ile-1760 of rat brain IIA Na(+) channel or the equivalent (Ile-1575) in the adult rat skeletal muscle isoform (mu 1) creates an artificial access path for QX. We examined the characteristics of mutation of mu 1-I1575 and the resulting QX path. In addition to allowing external QX222 access, I1575A accelerated decay of Na(+) current and shifted steady-state availability by -27 mV. I1575A had negligible effects on inorganic or organic cation selectivity and block by tetrodotoxin (TTX), saxitoxin (STX), or mu-conotoxin (mu-CTX). It exposed a site within the protein that binds membrane-permeant methanethiosulfonate ethylammonium (MTSEA), but not membrane-impermeant methanethiosulfonate ethyltrimethylammonium (MTSET) and methanethiosulfonate ethylsulfonate (MTSES). MTSEA binding abolished the QX path created by this mutation, without effects on toxin binding. The mu-CTX derivative R13N, which partially occluded the pore, had no effect on QX access. I1575A exposed two Cys residues because a disulfide bond was formed under oxidative conditions, but the exposed Cys residues are not those in domain IV S6, adjacent to Ile-1575. The Cys mutant I1575C was insensitive to external Cd(2+) and
MTS
compounds (MTSEA, MTSET, MTSES), and substitution of Ile with a negatively charged residue (I1575E) did not affect toxin binding. Ile-1575 seems to be buried in the protein, and its mutation disrupts the protein structure to create the QX path without disturbing the outer vestibule and its selectivity function.
Mol
Pharmacol 2001 Apr
PMID:Structural and gating changes of the sodium channel induced by mutation of a residue in the upper third of IVS6, creating an external access path for local anesthetics. 1125 11
Cisplatin [cis-
DDP
, cis-diamminedichloroplatinum(II)] is a potent anticancer drug that has been used successfully to treat tumors of the head, neck, lungs, and genitourinary tract. The biological activity of cisplatin was discovered serendipitously more than 30 years ago, and since that time research efforts have focused on elucidating its mechanism of action. The present review provides a historical perspective of our attempts to understand this complex phenomenon and the results of recent work that guides our current activities in this field. Continued efforts to understand the mechanism of genotoxicity of cisplatin are expected to lead to the discovery of new drugs and combinations for the improvement of cancer chemotherapy.
Prog Nucleic Acid Res
Mol
Biol 2001
PMID:Cisplatin: from DNA damage to cancer chemotherapy. 1152 87
Mohr-Tranebjaerg syndrome
(
MTS
/DFN-1) or deafness/dystonia syndrome results from a mutation in deafness/dystonia protein 1/translocase of mitochondrial inner membrane 8a (DDP1/TIMM8a). DDP1/TIMM8a is similar to a family of yeast proteins in the mitochondrial intermembrane space which mediate the import and insertion of inner membrane proteins. We now show that TIMM8a assembles in a 70 kDa complex in the intermembrane space with TIMM13. DDP1/TIMM8a is not detectable in fibroblasts derived from a patient with a missense mutation in the DDP1/TIMM8a gene; the point mutation results in cysteine-66 being changed to tryptophan-66 in the conserved 'twin CX(3)C' motif. The corresponding mutation in yeast translocase of inner membrane 8p (Tim8p) yields an unstable protein that does not assemble with yeast Tim13p. DDP1/TIMM8a, when expressed with TIMM13 in yeast mitochondria lacking the Tim8p-Tim13p complex, restores Tim23p import, and TIMM8a and TIMM13 can be cross-linked to the hTim23 import intermediate in rat and yeast mitochondria. In a similar manner to Tim8p, TIMM8a seemingly mediates the import of hTim23. Deafness/dystonia syndrome thus may be caused by decreased levels of Tim23 in the mitochondrial inner membrane in affected tissues.
Hum
Mol
Genet 2002 Mar 01
PMID:Human deafness dystonia syndrome is caused by a defect in assembly of the DDP1/TIMM8a-TIMM13 complex. 1187 42
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