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21.
Curcumin is a natural polyphenolic compound having an antiproliferative property, which recent evidence suggests is due to its ability to induce apoptosis. However, the molecular mechanisms through which curcumin induces apoptosis are not fully understood. Here, we report that the curcumin-induced apoptosis is mediated through the impairment of the ubiquitin-proteasome system. Exposure of curcumin to the mouse neuro 2a cells causes a dose-dependent decrease in proteasome activity and an increase in ubiquitinated proteins. Curcumin exposure also decreases the turnover of the destabilized enhanced green fluorescence protein, a model substrate for proteasome and cellular p53 protein. Like other proteasome inhibitors, curcumin targets proliferative cells more efficiently than differentiated cells and induces apoptosis via mitochondrial pathways. Addition of curcumin to neuro 2a cells induces a rapid decrease in mitochondrial membrane potential and the release of cytochrome c into cytosol, followed by activation of caspase-9 and caspase-3. 相似文献
22.
Characterization and expression of the mouse Hsc70 gene 总被引:2,自引:0,他引:2
A genomic clone encoding the mouse Hsc70 gene has been isolated and characterized by DNA sequence analysis. The gene is approximately 3. 9 kb in length and contains eight introns, the fifth, sixth and eighth of which encode the three U14 snoRNAs. The gene has been located on Chr 9 in the order Fli1-Itm1-Olfr7-Hsc70(Rnu14)-Cbl by genetic analysis. Expression of Hsc70 is universal in all tissues of the mouse, but is slightly elevated in liver, skeletal muscle and kidney tissue, while being depressed in testes. In cultured mouse NIH 3T3 cells or human HeLa cells, Hsc70 mRNA levels are low under normal conditions, but can be induced 8-fold higher in both lines by treatment with the amino acid analog azetidine. A similar induction is seen in cells treated with the proteosome inhibitor MG132 suggesting that elevated Hsc70 expression may be coupled to protein degradation. Surprisingly, expression of the human Hsc70 gene is also regulated by cell-cycle position being 8-10-fold higher in late G1/S-phase cells as opposed to the levels in early G1-phase cells. 相似文献
23.
The status of women, which is relative and multidimensional, has an important bearing on any long-term reduction in fertility. In Indian society, where cohabitation and childbearing are socially sanctioned only after marriage, the length of the first-birth interval affects the completed family size by influencing the spacing and childbearing pattern of a family. This study examines the influence of certain aspects of the status of married women--education, employment, role in family decision making, and age at marriage--along with three socioeconomic variables--per capita income of the family, social position of the household, and the caste system--on the duration of the first-birth interval in an urban Hindu society of the north-east Indian state of Assam. The data were analysed by applying life table and hazard regression techniques. The results indicate that a female's age at marriage, education, current age, role in decision making, and the per capita income of the household are the main covariates that strongly influence the length of the first-birth interval of Hindu females of urban Assam. Of all the covariates studied, a female's education appears to be a key mediating factor, through its influence on her probability of employment outside the home and thereby an earned income and on her role in family decision making. Unlike other Indian communities, the effect of the caste system does not have a significant effect on first-birth timing in this urban Hindu society. 相似文献
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Goswami S Chatterjee S Bhattacharyya SN Basu S Adhya S 《Nucleic acids research》2003,31(19):5552-5559
Import of nucleus-encoded tRNAs into the mitochondria of the kinetoplastid protozoon Leishmania involves recognition of specific import signals by the membrane-bound import machinery. Multiple signals on different tRNA domains may be present, and further, importable RNAs interact positively (Type I) or negatively (Type II) with one another at the inner membrane in vitro. By co-transfection assays, it is shown here that tRNATyr (Type I) transiently stimulates the rate of entry of tRNAIle (Type II) into Leishmania mitochondria in transfected cells, and conversely, is inhibited by tRNAIle. Truncation and mutagenesis experiments led to the co-localization of the effector and import activities of tRNATyr to the D domain, and those of tRNAIle to the variable region–T domain (V-T region), indicating that both activities originate from a single RNA–receptor interaction. A third tRNA, human tRNALys, is imported into Leishmania mitochondria in vitro as well as in vivo. This tRNA has Type I and Type II motifs in the D domain and the V-T region, respectively, and shows both Type I and Type II effector activities. Such dual-type tRNAs may interact simultaneously with the Type I and Type II binding sites of the inner membrane import machinery. 相似文献
27.
Goswami A Mirfakhrae KD Totleben MJ Swaminathan S Patel RN 《Journal of industrial microbiology & biotechnology》2001,26(5):259-262
Microbial reduction of α-chloroketone to α-chlorohydrin was studied as one of the approaches for construction of the chiral
center of the corresponding epoxide. About 100 microorganisms covering many species of Candida, Pichia, Hansenula, Geotrichum, Rhodococcus and Aureobasidium were screened to reduce the α-chloroketone stereospecifically. Many strains provided the R-α-chlorohydrin with 100% enantiomeric excess (ee), e.g., Candida sonorensis SC 16117, Geotrichum candidum SC 5469, Rhodotorula glutinis SC 16293, Sphingomonas paucimobilis SC 16113, Pichia silvicola SC 16159 and Rhodococcus equi SC 15835. Few microorganisms showed preferential formation of S-α-chlorohydrin after reduction. Among them, Pichia pinus SC 13864 and two Pichia methanolica strains SC 16116 and SC 13860 were the best, providing the S-α-chlorohydrin with ee of 88%, 79% and 78%, respectively. The enantiospecificity of the reduction by these Pichia species can be modified by changing the pH or prior heat treatment of the cells and S-α-chlorohydrin with ≥95% ee was obtained by appropriate modification of reaction conditions. Journal of Industrial Microbiology & Biotechnology (2001) 26, 259–262.
Received 23 June 2000/ Accepted in revised form 06 November 2000 相似文献
28.
Goswami PP Girish KS Chaudhuri P Tiwari V Akare SJ Harbola PC 《Indian journal of experimental biology》2002,40(1):109-110
A gene encoding beta toxin was amplified by polymerase chain reaction from C. perfringens type C isolate and cloned in pUC 19 vector. The nucleotide sequence was identical with C. perfringens type B beta toxin gene sequence. The Southern hybridization using labelled beta toxin gene probe revealed the presence of positive signals only in beta producing C. perfingens. 相似文献
29.
Baulmann DC Ohlmann A Flügel-Koch C Goswami S Cvekl A Tamm ER 《Mechanisms of development》2002,118(1-2):3-17
The development of the chamber angle was studied in the eyes of heterozygous Pax6(lacZ/+) mutant mice (Nature 387 (1997) 406). Mutations in PAX6 cause aniridia, a condition that is frequently associated with glaucoma, a blinding disease that may be associated with chamber angle defects. Mesenchymal cells were seen in the chamber angle at P1-P5. In wild-type mice, these cells differentiated into typical trabecular meshwork (TM) cells next to Schlemm's canal. In Pax6(lacZ/+) mice, TM cells remained undifferentiated and Schlemm's canal was absent. From P1 to P4, staining for beta-galactosidase and immunoreactivity for Pax6 were observed in chamber angle mesenchyme, but were absent later. Cultured murine TM cells expressed Pax6. The defects in chamber angle and TM differentiation were associated with a wide spectrum of other anterior eye defects, which included various degrees of iris hypoplasia and corneal haze, isolated iridocorneal adhesions and atypical coloboma, and a vascularized cornea in all adult animals. A third of the animals showed Peters' anomaly including corneal opacity and iridocorneal adhesions. The separation of the lens from the cornea was incomplete, and epithelial layers of lens and cornea were continuous. Pax6 activity is directly required for differentiation of the chamber angle. Variations in phenotype of Pax6(lacZ/+) mice appear not to involve direct dominant-negative or dose-dependent effects. 相似文献