scholarly journals INFLUENCE OF YEAST EXTRACT ON GENE EXPRESSION OF CRWRKY1 AS A REGULATORY GENE IN ALKALOIDS PATHWAY IN CATHARANTHUS ROSEUS (L.) G. DON

2018 ◽  
Vol 26 (2) ◽  
pp. 647-654
Author(s):  
Mona Moghazee ◽  
Fatma Badway ◽  
Rania Younis ◽  
S. Hassanein
1988 ◽  
Vol 8 (8) ◽  
pp. 3439-3447 ◽  
Author(s):  
W Bajwa ◽  
T E Torchia ◽  
J E Hopper

GAL3 gene expression is required for rapid GAL4-mediated galactose induction of the galactose-melibiose regulon genes in Saccharomyces cerevisiae. Here we show by Northern (RNA) blot analysis that GAL3 gene expression is itself galactose inducible. Like the GAL1, GAL7, GAL10, and MEL1 genes, the GAL3 gene is severely glucose repressed. Like the MEL1 gene, but in contrast to the GAL1, GAL7, and GAL10 genes, GAL3 is expressed at readily detectable basal levels in cells grown in noninducing, nonrepressing media. We determined the sequence of the S. cerevisiae GAL3 gene and its 5'-noncoding region. Within the 5'-noncoding region of the GAL3 gene, we found two sequences similar to the UASGal elements of the other galactose-melibiose regulon genes. Deletion analysis indicated that only the most ATG proximal of these sequences is required for GAL3 expression. The coding region of GAL3 consists of a 1,275-base-pair open reading frame in the direction of transcription. A comparison of the deduced 425-amino-acid sequence with the protein data bank revealed three regions of striking similarity between the GAL3 protein and the GAL1-specified galactokinase of Saccharomyces carlsbergensis. One of these regions also showed striking similarity to sequences within the galactokinase protein of Escherichia coli. On the basis of these protein sequence similarities, we propose that the GAL3 protein binds a molecule identical to or structurally related to one of the substrates or products of the galactokinase-catalyzed reaction.


Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3368-3375 ◽  
Author(s):  
XingJia Wang ◽  
Matthew T. Dyson ◽  
Youngah Jo ◽  
Douglas M. Stocco

Abstract To study the mechanism for the regulatory effect of arachidonic acid (AA) on steroidogenesis, the role of cyclooxygenase (COX) in steroid production and steroidogenic acute regulatory (StAR) gene expression was investigated. Although stimulation with 0.05 mm dibutyryl cAMP (Bt2cAMP) did not increase StAR protein or progesterone in MA-10 mouse Leydig cells, the addition of 1 μm of the COX inhibitor indomethacin increased StAR protein expression and progesterone production by 5.7-fold and 34.3-fold, respectively. In the presence of indomethacin, the level of Bt2cAMP required for maximal steroidogenesis was reduced from 1.0 mm to 0.25 mm. Similar results were obtained in studies on StAR promoter activity and in Northern blot analyses of StAR mRNA expression, suggesting that inhibition of COX activity enhanced StAR gene transcription. COX2 (an inducible isoform of COX) was constitutively detected in MA-10 cells. Although SC560, a selective COX1 inhibitor, did not affect steroidogenesis, the COX2 inhibitor NS398 significantly enhanced Bt2cAMP-stimulated StAR protein expression and steroid production. Overexpression of the COX2 gene in COS-1 cells significantly inhibited StAR promoter activity. The results of the present study suggest that inhibition of COX2 activity increases the sensitivity of steroidogenesis to cAMP stimulation in MA-10 Leydig cells.


Aging ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 7397-7415
Author(s):  
Zegui Tu ◽  
Xiancheng Chen ◽  
Tian Tian ◽  
Guo Chen ◽  
Meijuan Huang

2012 ◽  
Vol 142 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Pedro Manoel M. Moraes-Vieira ◽  
Maisa C.S. Takenaka ◽  
Hernandez M. Silva ◽  
Sandra Maria Monteiro ◽  
Fabiana Agena ◽  
...  

Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3267-3273 ◽  
Author(s):  
Akhilesh K. Pandey ◽  
Xiangling Yin ◽  
Randolph B. Schiffer ◽  
James C. Hutson ◽  
Douglas M. Stocco ◽  
...  

Recent studies suggested an involvement of thromboxane A2 in cyclooxygenase-2-dependent inhibition of steroidogenic acute regulatory (StAR) gene expression. The present study further investigated the role of thromboxane A2 receptor in StAR gene expression and steroidogenesis in testicular Leydig cells. The thromboxane A2 receptor was detected in several Leydig cell lines. Blocking thromboxane A2 binding to the receptor using specific antagonist SQ29548 or BM567 resulted in dose-dependent increases in StAR protein and steroid production in MA-10 mouse Leydig cells. The results were confirmed with Leydig cells isolated from rats. StAR promoter activity and StAR mRNA level in the cells were also increased after the treatments, suggesting an involvement of the thromboxane A2 receptor in StAR gene transcription. Furthermore study indicated that blocking the thromboxane A2 receptor reduced dosage sensitive sex reversal-adrenal hypoplasia congenita critical region on the X chromosome, gene 1 protein, a transcriptional repressor of StAR gene expression. Specific binding of the antagonists to the receptors on cellular membrane was demonstrated by binding assays using 3H-SQ29548 and binding competition between 3H-SQ29548 and BM567. Whereas SQ29548 enhanced cAMP-induced StAR gene expression, in the absence of cAMP, it was unable to increase StAR protein and steroidogenesis. However, when the receptor was blocked by the antagonist, subthreshold levels of cAMP were able to induce maximal levels of StAR protein expression, suggesting that blocking the thromboxane A2 receptor increase sensitivity of MA-10 cells to cAMP stimulation. Taken together, the results from the present and previous studies suggest an autocrine loop, involving cyclooxygenase-2, thromboxane A synthase, and thromboxane A2 and its receptor, in cyclooxygenase-2-dependent inhibition of StAR gene expression.


2003 ◽  
Vol 185 (18) ◽  
pp. 5611-5626 ◽  
Author(s):  
Eric Soupene ◽  
Wally C. van Heeswijk ◽  
Jacqueline Plumbridge ◽  
Valley Stewart ◽  
Daniel Bertenthal ◽  
...  

ABSTRACT Escherichia coli strain MG1655 was chosen for sequencing because the few mutations it carries (ilvG rfb-50 rph-1) were considered innocuous. However, it has a number of growth defects. Internal pyrimidine starvation due to polarity of the rph-1 allele on pyrE was problematic in continuous culture. Moreover, the isolate of MG1655 obtained from the E. coli Genetic Stock Center also carries a large deletion around the fnr (fumarate-nitrate respiration) regulatory gene. Although studies on DNA microarrays revealed apparent cross-regulation of gene expression between galactose and lactose metabolism in the Stock Center isolate of MG1655, this was due to the occurrence of mutations that increased lacY expression and suppressed slow growth on galactose. The explanation for apparent cross-regulation between galactose and N-acetylglucosamine metabolism was similar. By contrast, cross-regulation between lactose and maltose metabolism appeared to be due to generation of internal maltosaccharides in lactose-grown cells and may be physiologically significant. Lactose is of restricted distribution: it is normally found together with maltosaccharides, which are starch degradation products, in the mammalian intestine. Strains designated MG1655 and obtained from other sources differed from the Stock Center isolate and each other in several respects. We confirmed that use of other E. coli strains with MG1655-based DNA microarrays works well, and hence these arrays can be used to study any strain of interest. The responses to nitrogen limitation of two urinary tract isolates and an intestinal commensal strain isolated recently from humans were remarkably similar to those of MG1655.


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