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We have examined the behavior of the phosphorothioate antisense Rel A (NF-kappaB p65) oligodeoxynucleotide (oligo) and related molecules. Because of the presence of a G-tetrad near its 5'terminus, this molecule is capable of forming tetraplexes and other higher order structures in a temperature and time dependent manner. The G-tetrad in the phosphodiester congener is protected from methylation by dimethylsulfate when the oligomer is 3'-phosphorylated. However, this protection is completely lost when it is 5'phosphorylated, indicating that the formation of at least some higher order structures has been blocked. In addition, we also prevented tetraplex formation by substitution of 7-deazaguanosine (7-DG) for guanosine at several positions within and outside of the tetrad. This substitution retains Watson-Crick base pair hybridization but prevents Hoogsteen base-pair interactions. When murine K-Balb cells were treated with 20microM antisense RelA oligo, complete blockade of nuclear translocation of RelA was observed. However, this effect was virtually entirely abrogated in most cases by 7-DG substitution within the tetrad, but retained when the substitution was made 3' to the tetrad. The AS RelA-induced downregulation of Sp-1 activity behaved similarly after 7-DG substitution. Thus, the parent phosphorothioate AS RelA molecule cannot be a Watson-Crick antisense agent. However, these conclusions cannot be extrapolated to other G-tetrad containing oligomers and each must be evaluated individually.  相似文献   

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Yeast cells mutated in YRB2, which encodes a nuclear protein with similarity to other Ran-binding proteins, fail to export nuclear export signal (NES)-containing proteins including HIV Rev out of the nucleus. Unlike Xpo1p/Crm1p/exportin, an NES receptor, Yrb2p does not shuttle between the nucleus and the cytoplasm but instead remains inside the nucleus. However, by both biochemical and genetic criteria, Yrb2p interacts with Xpo1p and not with other members of the importin/karyopherin beta superfamily. Moreover, the Yrb2p region containing nucleoporin-like FG repeats is important for NES-mediated protein export. Taken together, these data suggest that Yrb2p acts inside the nucleus to mediate the action of Xpo1p in at least one of several nuclear export pathways.  相似文献   

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The ability of the shoot apical meristem to multiply and distribute its meristematic potential through the formation of axillary meristems is essential for the diversity of forms and growth habits of higher plants. In the lateral suppressor mutant of tomato the initiation of axillary meristems is prevented, thus offering the unique opportunity to study the molecular mechanisms underlying this important function of the shoot apical meristem. We report here the isolation of the Lateral suppressor gene by positional cloning and show that the mutant phenotype is caused by a complete loss of function of a new member of the VHIID family of plant regulatory proteins.  相似文献   

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The relationships between angiotensin-converting enzyme (ACE) gene insertion (I) / deletion (D) polymorphism and left ventricular hypertrophy induced by hypertension or idiopathic hypertrophic cardiomyopathy have been studied. However, little is known about the association between this polymorphism and left ventricular hypertrophy induced by volume overload. The relationship between left ventricular hypertrophy and the ACE gene I/D polymorphism was examined in 80 maintenance hemodialysis patients (mean age: 60.1+/-1.4 years). Multivariate regression analysis showed that the left ventricular mass index calculated by M-mode echocardiography was associated with serum creatinine (p = 0.040), male gender (p = 0.027), antihypertensive drug treatment (p = 0.026), weight gain between hemodialysis (p = 0.018) and mean blood pressure after hemodialysis (p=0.010), but not with ACE I/D genotype (p = 0.69). These findings suggest that although hemodialysis patients seem to be under volume overload, ACE genotype may not be involved in their left ventricular hypertrophy. Hypertension and other factors related to renal failure are involved in the left ventricular hypertrophy in chronic hemodialysis patients.  相似文献   

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SOX genes share a high sequence identity with the HMG box present in the testis determining gene SRY. We have identified a HMG box-like sequence motif on six contiguous cosmids, which cross-hybridize to a SOX9 cDNA probe. A data base search revealed a high similarity of the deduced amino acid sequence to the human SOX12 and the murine Sox16 HMG domains. The cosmids were assigned to chromosome 17p13 by FISH analysis.  相似文献   

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Silver-stainable proteins (SSPs) are aspartic acid-rich nuclear proteins which are silver stained under very specific conditions. Using a degenerate oligodeoxyncleotide probe which codes for acidic amino acid residues, a cDNA for a new SSP, referred to as SSP29, has been isolated. The cDNA-derived amino acid sequence shows SSP29 has a molecular mass of 29 kDa, leucine-rich repeats (LRR) near the NH2-terminal region and acidic clusters at the COOH-terminal portion, indicating that SSP29 is also a member of the LRR subfamily of acidic proteins which have been shown to be involved in antigen-mediated cellular responses, leukemogenesis and differentiation. SSP29 can be stained by Ag-NOR staining. SSP29 is expressed in all human tissues and cell lines tested, localized to nucleoplasm and translocated partially to the nucleoli after heat shock. Its interaction with RNA polymerase I suggests that SSP29 may participate in signal transduction that directs nucleolar activities by regulating ribosomal RNA biosynthesis.  相似文献   

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The combination of H2O2 and vanadate generates aqueous peroxovanadium (pV) species, which are effective cell-permeable oxidants, and potent inhibitors of protein-tyrosine phosphatases. As a result, treatment of intact cells with pV compounds significantly enhances protein Tyr phosphorylation. Here we demonstrate that treatment of intact rat hepatoma Fao cells with pV markedly enhances Tyr phosphorylation of a 75-kDa protein, termed pp75. Amino-terminal sequencing of pp75 revealed that this protein is a member of the 70-75-kDa heat shock protein family, which includes PBP-74, glucose-related protein (GRP)-75, and mortalin. Tyr phosphorylation of pp75 is selective, because other proteins that belong to the heat shock protein 70 family, such as GRP-72, Bip (GRP-78), and HSC-70 fail to undergo Tyr phosphorylation when cells are treated with pV. Our findings suggest that heat shock proteins such as pp75 may undergo tyrosine phosphorylation when intact cells are subjected to oxidative stress induced by pV compounds.  相似文献   

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By using a model system for cell transformation mediated by the cooperation of the activated H-ras oncogene and the inactivated p53 tumor suppressor gene, rCop-1 was identified by mRNA differential display as a gene whose expression became lost after cell transformation. Homology analysis indicates that rCop-1 belongs to an emerging cysteine-rich growth regulator family called CCN, which includes connective-tissue growth factor, CYR61, CEF10 (v-src inducible), and the product of the nov proto-oncogene. Unlike the other members of the CCN gene family, rCop-1 is not an immediate-early gene, it lacks the conserved C-terminal domain which was shown to confer both growth-stimulating and heparin-binding activities, and its expression is lost in cells transformed by a variety of mechanisms. Ectopic expression of rCop-1 by retroviral gene transfers led to cell death in a transformation-specific manner. These results suggest that rCop-1 represents a new class of CCN family proteins that have functions opposing those of the previously identified members.  相似文献   

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Many of the current tuberculosis control programmes in the Russian Federation are based on costly strategies which are underfunded and use long, individualized treatment regimens. This article compares, using a cost-effectiveness analysis, the new WHO strategy implemented in the Ivanovo Oblast (case-finding among symptomatic patients (SCF) and shorter regimens) and the old strategy (active screening of the asymptomatic population (ACF) and longer regimens). The cost per case cured was calculated at different levels of cure rate (45-95%) using three scenarios to describe the new WHO strategy (use of WHO-recommended regimens and three options at increasing rates of admission) and a fourth scenario to describe the old strategy (all patients admitted for the whole treatment and longer regimens). The cost per case detected was determined by calculating the following: yield of the new and old strategy (number of examinations necessary to diagnose one case); cost of the diagnostic process; multiplying yield per cost according to the three scenarios describing the new WHO strategy and a fourth scenario describing the old strategy. In the Ivanovo Oblast the cost per case cured, at 85% cure rate level, ranged from US$ 1197 (new strategy, scenario 1 without food) to US$ 6293 (old strategy, scenario 4) the cost per case detected ranged from US$ 1581 (new strategy, scenario 1) to US$ 4000 (old strategy, scenario 4). Significant savings can result from shifting towards the new WHO strategy. Decision-makers and health administrators should be responsible for re-investing the financial and human resources mobilized by the adoption of cost-effective strategies within the TB control programme.  相似文献   

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