scholarly journals Induction of N-acetylglucosamine-catabolic pathway in spheroplasts of Candida albicans

1979 ◽  
Vol 178 (2) ◽  
pp. 427-431 ◽  
Author(s):  
B Singh ◽  
A Datta
Keyword(s):  
Protein Synthesis ◽  
Candida Albicans ◽  
Enzyme Activities ◽  
Transcriptional Level ◽  
Uptake System ◽  
Catabolic Pathway ◽  
High Affinity ◽  
Catabolic Enzymes ◽  
Rna And Protein Synthesis ◽  
New Protein

Synthesis of N-acetylglucosamine-catabolic enzymes, namely permease (high-affinity uptake system), kinase and deaminase was studied in the spheroplasts of the yeast Candida albicans. The presence of N-acetylglucosamine as inducer is essential for the induced synthesis of these enzymes in the spheroplasts, which were active for at least 8–9 h. However, some of the newly synthesized kinase and deaminase leaked out from the spheroplasts into the medium during induction. Experiments with inhibitors of RNA and protein synthesis indicate that the appearance of new enzyme activities is dependent on concomitant new protein synthesis and the inducer operates at a transcriptional level. However, inhibitors of DNA synthesis, e.g. mitomycin-C and hydroxyurea, had no effect on the synthesis of these enzymes.

scholarly journals Induction of N-acetylglucosamine kinase in yeast

1974 ◽  
Vol 141 (2) ◽  
pp. 593-595 ◽  
Author(s):  
A. Bhattacharya ◽  
M. Puri ◽  
A. Datta
Keyword(s):  
Protein Synthesis ◽  
Enzyme Activity ◽  
Candida Albicans ◽  
Enzyme Synthesis ◽  
Transcriptional Level ◽  
Protein Synthesis Inhibitors ◽  
Rna And Protein Synthesis ◽  
New Protein

The presence of N-acetylglucosamine is essential for the induced synthesis of N-acetylglucosamine kinase in Candida albicans. The enzyme synthesis stops and its concentration in the cells declines rapidly as soon as N-acetylglucosamine is removed from the medium. Experiments with RNA- and protein-synthesis inhibitors indicate that the appearance of new enzyme activity is dependent on concomitant new protein synthesis and the inducer operates at a transcriptional level.

Mechanism of dexamethasone-mediated interleukin-8 gene suppression in cultured airway epithelial cells

2001 ◽  
Vol 280 (1) ◽  
pp. L107-L115 ◽  
Author(s):  
Mary Mann-Jong Chang ◽  
Maya Juarez ◽  
Dallas M. Hyde ◽  
Reen Wu
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Epithelial Cells ◽  
Actinomycin D ◽  
Airway Epithelial Cells ◽  
Interleukin 8 ◽  
Transcriptional Level ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
New Protein

The effects of dexamethasone, a glucocorticoid analog, on interleukin 8 (IL-8) gene expression were studied in cultures of primary human tracheobronchial epithelial cells and an immortalized human bronchial epithelial cell line, HBE1 cells. Dexamethasone inhibited IL-8 mRNA and protein expression in a concentration- and time-dependent manner. The inhibition did not occur at the transcriptional level since both nuclear run-on activity and IL-8 promoter-reporter gene expression assay revealed no significant effect. Instead, there was a change in IL-8 mRNA stability in dexamethasone-treated cultures. Under actinomycin D treatment, IL-8 mRNA was quite stable in dexamethasone-depleted cultures, while in dexamethasone-pretreated cultures, IL-8 message was rapidly degraded within the first hour, then leveled off. When dexamethasone and actinomycin D were added simultaneously to dexamethasone-depleted cultures, IL-8 mRNA remained rather stable. When cycloheximide was used to inhibit new protein synthesis, dexamethasone-dependent inhibition was not observed. These results suggest that a posttranscriptional mechanism, which requires dexamethasone-dependent new protein synthesis, is involved in the regulation of IL-8 mRNA by dexamethasone in airway epithelial cells.

The Candida albicans CTR1 gene encodes a functional copper transporter

Microbiology ◽  
2003 ◽  
Vol 149 (6) ◽  
pp. 1461-1474 ◽  
Author(s):  
Marcus E. Marvin ◽  
Peter H. Williams ◽  
Annette M. Cashmore
Keyword(s):  
Candida Albicans ◽  
Amino Acid ◽  
Protein Product ◽  
Uptake System ◽  
Copper Binding ◽  
Null Mutant ◽  
Copper Uptake ◽  
Similar System ◽  
Copper Transporter ◽  
High Affinity

Copper and iron uptake in Saccharomyces cerevisiae are linked through a high-affinity ferric/cupric-reductive uptake system. Evidence suggests that a similar system operates in Candida albicans. The authors have identified a C. albicans gene that is able to rescue a S. cerevisiae ctr1/ctr3-null mutant defective in high-affinity copper uptake. The 756 bp ORF, designated CaCTR1, encodes a 251 amino acid protein with a molecular mass of 27·8 kDa. Comparisons between the deduced amino acid sequence of the C. albicans Ctr1p and S. cerevisiae Ctr1p indicated that they share 39·6 % similarity and 33·0 % identity over their entire length. Within the predicted protein product of CaCTR1 there are putative transmembrane regions and sequences that resemble copper-binding motifs. The promoter region of CaCTR1 contains four sequences with significant identity to S. cerevisiae copper response elements. CaCTR1 is transcriptionally regulated in S. cerevisiae in response to copper availability by the copper-sensing transactivator Mac1p. Transcription of CaCTR1 in C. albicans is also regulated in a copper-responsive manner. This raises the possibility that CaCTR1 may be regulated in C. albicans by a Mac1p-like transactivator. A C. albicans ctr1-null mutant displays phenotypes consistent with the lack of copper uptake including growth defects in low-copper and low-iron conditions, a respiratory deficiency and sensitivity to oxidative stress. Furthermore, changes in morphology were observed in the C. albicans ctr1-null mutant. It is proposed that CaCTR1 facilitates transport of copper into the cell.

FEMALE ENDOCRINE CONTROL MECHANISMS DURING THE NEONATAL PERIOD

1972 ◽  
Vol 70 (2) ◽  
pp. 396-408 ◽  
Author(s):  
K.-D. Schulz ◽  
H. Haarmann ◽  
A. Harland
Keyword(s):  
Protein Synthesis ◽  
Reproductive System ◽  
Rna Synthesis ◽  
Neonatal Period ◽  
High Dose ◽  
Female Reproductive System ◽  
Endocrine Control ◽  
Hypothalamic Region ◽  
Rna And Protein Synthesis ◽  
Physiological Dose

ABSTRACT The present investigation deals with the oestrogen-sensitivity of the female reproductive system during the neonatal period. Newborn female guinea pigs were used as test animals. At different times after a single subcutaneous injection of a physiological dose of 0.1 μg or an unphysiologically high dose of 10 μg 17β-oestradiol/100 g body weight, the RNA- and protein-synthesis was examined in the hypothalamic region, pituitary, cerebral cortex, liver, adrenal gland, ovary and uterus. With a physiological dose an increase in organ weight, protein content, RNA-and protein-synthesis was found only in the uterus. These alterations turned out to be dose-dependent. In addition to the findings in the uterus an inhibition of the aminoacid incorporation rate occurred in the liver following the injection of the high oestradiol dose. As early as 1 hour after the administration of 0.1 μg 17β-oestradiol an almost 100% increase in uterine protein synthesis was detectable. This result demonstrates a high oestrogen-sensitivity of this organ during the neonatal period. All the other organs of the female reproductive system such as the hypothalamus, pituitary and ovary did not show any oestrogen response. Therefore the functional immaturity of the uterus during post partem life is not the result of a deficient hormone sensitivity but is correlated with the absence of a sufficient hormonal stimulus at this time. The investigation on the effects of actinomycin resulted in different reactions in the uterus and liver. In contrast to the liver a paradoxical actinomycin effect was found in the uterus after treatment with actinomycin alone. This effect is characterized by a small inhibition of RNA-synthesis and a 50% increase in protein synthesis. The treatment of the newborn test animals with actinomycin and 17β-oestradiol together abolished the oestrogen-induced stimulation of the uterine RNA-and protein-synthesis. Consequently, the effect of oestrogens during the neonatal period is also connected with the formation of new proteins via an increased DNA-directed RNA-synthesis.

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