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Genes 29,48 and 54 of bacteriophage T4, coding for specific tube associated proteins, were cloned to the expression vector pT7-5. The molecular mass of the products of these genes was estimated to be 64,39 and 36 kDa, respectively. The examined genes are cotranscribed with genes 51,27 and 28 from the same DNA strand and a common late promoter sequence located downstream of gene 51.
Stilbene synthases (STSs) are enzymes that play a critical role in the biosynthesis of stilbene, phytoalexins in a small number of unrelated plant species, and are induced by various biotic and abiotic stressors like pathogen attack, UV-irradiation or ozone exposure. To investigate the molecular basis for ozone-induced plant stress responses, we have examined the promoter of the grapevine resveratrol synthase (Vst1). In this report we summarize the influence of ozone on gene regulation. In transgenic tobacco a chimeric gene construct, containing the Vst1 promoter combined with the β-glucuronidase (GUS) reporter gene, is rapidly induced by ozone (0.1 µl·l⁻¹, 12 h). The same construct is also strongly induced by ethylene (20 µl·l⁻¹, 12 h). Promoter deletion analysis of the 5′ flanking sequence identified a positive regulatory element between −430 bp and −280 bp. This region contains ethylene-responsive enhancer elements, as well as an elicitor-responsive sequence in inverse orientation.
Human PCAN1 (prostate cancer gene 1) is a prostate-specific gene that is highly expressed in prostate epithelial tissue, and frequently mutated in prostate tumors. To better understand the regulation of the PCAN1 gene, a 2.6-kb fragment of its 5′ flanking region was obtained by PCR. Its promoter activity was examined via the dual-luciferase reporter assay after it had been cloned into a pGL3-basic vector generating pGL3-p2.6kb and transfected into LNCaP cells. pGL3-basic and pGL3-control were respectively used as the negative and positive controls. Sequence analysis with the MatInspector database showed that some possible binding sites for the transcriptional factors, NKX3.1, P53, SP1, cEBP and the PPAR/RXR heterodimers may locate on a 2.6-kb region upstream of the PCAN1 gene. To examine the relevant regulation of PCAN1, pGL3-p2.6kb was transfected into the prostate cancer cell line LNCaP, which was treated with R1881 (10−7∼10−9 mol/l), 17β-estradiol (17β-E2, 10−7∼10−9 mol/l), all-trans-retinoic acid (all-trans-RA, 10−5∼10−7 mol/l) or 9-cis-retinoic acid (9-cis-RA, 10−5∼10−7 mol/l), and eukaryotic expression plasmids of NKX3.1, p53, Sp1, Pten, PPARγ or cEBPα were cotransfected with pGL3-p2.6kb into LNCaP cells. pRL-TK, a Renilla luciferase reporter vector, was cotransfected into all the transfection lines as an internal control. The activities of pGL3-p2.6kb (PCAN1 promoter) were analyzed via the dual-luciferase reporter assay 48 h after transfection. The results showed that 9-cis-RA enhanced the PCAN1 promoter activity in a dose-dependent manner, while R1881, 17β-E2 and all-trans-RA had no significant effect on PCAN1 promoter activities. Cotransfection with pGL3-p2.6kb and the expression plasmids of NKX3.1, p53, Sp1 or Pten respectively resulted in 1.66-, 2.48-, 2.00-and 1.72-fold 2.6 kb PCAN1 promoter activity increases relative to the controls, which were cotransfected with pcDNA3.1(+), while cotransfection of PPARγ and cEBPα yielded no significant effect on PCAN1 promoter activities. These results could be applied for further study of the function and transcription regulation of the PCAN1 gene in prostate development and carcinogenesis.
The aim of this study was to verify the hypothesis that insertion/deletion (indel) polymorphisms within the promoter and intron 1 sequences of the prion protein (PRNP) gene can affect the breeding value of Holstein-Friesian bulls. The experimental material included 261 Holstein-Friesian bulls born between 1997 – 2002. It was shown that the polymorphism in the intron 1 (12 bp indel) sequence had a more significant effect on the analyzed traits than a polymorphism in the promotor (23 bp indel) sequence. A deletion allele within intron 1 (12del) significantly increased the bulls’ breeding value for milk yield (p=0.001), protein yield (p=0.042), type and conformation (p=0.018),udder width (p=0.003), dairy character (p=0.004), and decreased days open (p=0.022). A deletion allele (23del) at the polymorphic locus of the promoter significantly decreased the bulls’ breeding value for milk yield (p=0.001), udder width (p=0.029) and dairy character (p=0.033). Analysis of both alleles showed that 23del-12del haplotype increased the bulls’ breeding value for udder traits:udder (p=0.008), fore udder (p=0.043) and udder depth (p=0.041), and decreased for fat kontent (p=0.047) and conformation traits - body depth (p<0.001), chest width (p=0.029) and rear leg set - side view (p=0.029). Also positive effect of 23del-12ins haplotype for days open (p=0.003) and days between calving and first insemination (p=0.045) was observed.
Podocin (NPHS2) is a component of the glomerular slit membrane with major regulatory functions in the renal permeability of proteins. A loss of podocin and a decrease in its resynthesis can influence the outcome of renal diseases with nephrotic syndrome, such as minimal change glomerulonephritis, focal segmental glomerulosclerosis (FSGS) and membranous nephropathy. The transcriptional regulation of podocin may play a major role in these processes. We defined the transcriptional regulation of the human podocin gene and the influence of single nucleotide polymorphisms (SNPs) within its promoter region in the podocytes using reporter gene constructs and gel shift analysis. In addition, we took genomic DNA from healthy Caucasian blood donors and from biopsies of kidneys with defined renal diseases and screened it for podocin promoter SNPs. Our data shows that the transcription of podocin is mainly regulated by the transcription factor Lmx1b, which binds to a FLAT-F element and displays enhancer function. With the SNP variant −116T, there was a significant reduction in luciferase activity, and nuclear protein binding was observed, while the SNP −670C/T did not display functionality. The allelic distribution of −116C/T in patients with kidney diseases leading to nephrotic syndrome was not significantly different from that in the control group. Our data indicates that among other factors, podocin is specifically regulated by the transcription factor Lmx1b and by the functional polymorphism -116C/T. However, there is no association between −116C/T and susceptibility to minimal change glomerulonephritis, focal segmental glomerulosclerosis or membranous nephropathy.
The kinetics and thermodynamics of the formation of the transcriptional open com­plex (RPo) by Escherichia coli RNA polymerase at the synthetic Pa promoter bearing consensus -10 and -35 recognition hexamers were studied in vitro. Previously, this promoter was used as a control one in studies on the effect of DNA bending by An • Tn sequences on transcription initiation and shown to be fully functional in E. coli (Łoziński et al., 1991, Nucleic Acids Res. 19, 2947; Łoziński & Wierzchowski, 1996, Acta Biochim. Polon. 43, 265). The data now obtained demonstrate that the mecha­nism of Pa-RPo formation and dissociation conforms to the three-step reaction model: bind-nucleate-melt, commonly accepted for natural promoters. Measurements of the dissociation rate constant of Pa-RPo as a function of MgCl2 concentration allowed us to determine the number of Mg2+ ions, nMg ~ 4, being bound to the RPo in the course of renaturation of the melted DNA region. This number was found constant in the tem­perature range of 25-37°C, which indicates that under these conditions the complex remaines fully open. This observation, taken together with the recent evidence from KMnO4 footprinting studies that the length of the melted region in Pa-RPo at 37°C is independent of the presence of Mg2+ ions (Łoziński & Wierzchowski, 2001, Acta Biochim. Polon. 48, 495), testifies that binding of Mg2+ to RPo does not induce its fur­ther isomerization, which has been postulated for the λPr-RPo complex (Suh et al., 1992, Biochemistry 31, 7815; 1993, Science 259, 358).
The aim of the study was to examine the allelic frequency of the -3826A>G mutation of UPC1 in patients with familiar obesity and to investigate putative association of this polymorphism with metabolic disorders. One hundred and eighteen overweight / obese patients participated in the study. The UCP1 polymorphism was determined by RFLP. Glucose, lipid, insulin and leptin levels were measured both during OGTT and OLTT. The majority of patients had a homozygous A/A genotype (51,38%), while 14,68% had a G/G genotype. We found no significant association of the G allele with either BMI or glucose tolerance. Patients with the homozygous G/G genotype had significantly higher fasting levels of TG (p<0.04) and decreased levels of HDL-cholesterol (p=0,004). They also had an increased concentration of FFA and the rise of TG levels during the OLTT compared to controls was significant (p=0,058). In addition, the carriers of the G/G genotype had the lowest insulin levels both during OGTT and OLTT. In our study we have demonstrated that the -3826A>G polymorphism of UCP1 does not play a major role in the development of obesity and/or disturbances of glucose metabolism. However, the increased levels of TG and FFA and decreased levels of HDL observed in carriers of the G allele suggest FFA-induced impairment of the HDL turnover and disturbance of the ß-cell function, both of which are risk factors for endothelial injury.
An in vitro transcription system from the trout testis nuclei was developed to study trout protamine gene expression. The protamine promoter contains, among others, two regulatory elements: 1) a cAMP-responsive element or CRE element (TGACGTCA) which is present in position 5' to TATA box, and 2) GC box (CCGCCC) which is present in position 3' to TATA box. The removal of the CRE-binding protein by titration (by the addition of appropriate oligonucleotides to the incubation mixture) resulted in a decrease in transcription of the protamine gene. These results were confirmed by experiments in which the pure CRE-binding factor (TPBP1) was used, as well as by those where a stimulatory effect of cAMP on protamine promoter transcription was observed. On the other hand, addition of oligonucleotides containing the GC-box sequence enhanced the protamine gene transcription indicating that the protein (Spl like) which binds to this sequence acts as a repressor of protamine gene expression. These results confirm the previously proposed model which suggested that the GC box played a role in negative regulation of the protamine gene expression. Involvement of some other factors in this process was also discussed.
The effects of cow’s genotype at αS1- and αS2-casein gene 5’-noncoding regions (promoters) were determined on selected milk production traits of the 135 Polish Black-and-White (Polish Friesian) cows as related to the animal’s age, lactation parity and stage, and somatic cell count. Cows of the AA genotype of αS1-casein gene yielded more milk daily than AG heterozygotes. Also, the daily yield of solids-non-fat, protein and lactose was higher in AA genotype cows. Milk of the cows with genotype CC of αS2-casein contained more lactose but less protein than that of the CT heterozygotes. The daily protein yield was slightly (but significantly) higher in the cows of the CT αS2-casein genotype. In summary, the results showed that genetic variants of αS1- and αS2-casein 5’-noncoding regions had only a slight effect on milk production traits of the Polish Black-and-White cows. Nevertheless,the AA genotype of αS1-casein seemed favourable for higher milk yield, as well as for lactose and protein content.
Selected cDNA clones of Arabidopsis thaliana, isolated previously by suppression subtractive hybridisation, were used to differentiate between abiotic stress factors. Changes in expression patterns of 79 genes were examined by array analysis in Arabidopsis thaliana after fumigation with ozone and after short- or long-term mercuric-ion exposure. Substantial changes in the abundance of 42 transcripts were recorded in response to the treatments, and 6 transcript clusters were observed. The abundance of 37 mRNAs was increased more then 1.5-fold, whereas that of 5 mRNAs was reduced. The abundances of 5, 6 and 9 mRNAs were specifically in creased by short-term mercury application, ozone fumigation, and long-term mercuric-ion exposure, respectively. The transcription of the other 5 transcripts was induced by both ozone and short-term mercuric-ion treatment. The abundance of 10 different mRNAs was in creased by the different mercuric-ion applications. Two transcripts were induced by ozone fumigation, as well as long-term, mercury treatment. Finally, 5 transcripts were repressed by ozone exposure, and 3 out of them by short-term mercuric-ion treatment. These results show that the array technique can be used to analyse the expression pattern in Arabidopsis thaliana under ozone and mercuric-ion stress. Searches against the Arabidopsis database furthermore provide a classification of most genes. In addition possible cis-acting regulatory elements were identified by an in silico approach using the MIPS Arabidopsis thaliana database.
Recent studies showed, that ozone-induced gene expression occurs via at least two different signalling mechanisms that are ethylene-dependent (fi-1,3-glucanases) and ethylene-independent independent (stilbene synthase). To identify transacting factors involved in ozone-induced gene expression we analyzed a 150 bp PCR fragment of an ozone-responsive promoter segment of the grape vine resveratrol synthase gene (Vst1) in combination of a cDNA library prepared from ozone-treated tobacco plants, using the yeast one-hybrid screening system. Two cDNA clones that encode WRKY binding proteins were isolated by this screening technique. The open reading frame of NtWRKY10 and NtWRKYll showed an identity of 93.5 % and the deduced amino acid sequence an identity of 89.3 %. According to the WRKY domain classification in Arabidopsis, both proteins belong to subgroup II. Comparison with known tobacco WRKY proteins indicate that WRKY10 and WRKY11 belong to a new class of tobacco WRKY transcription factors. Electrophoretic mobility shift assays (EMSA) of yeast extracts, containing the WRKY fusion protein showed a weak binding to the radioaclively labelled 150 bp ozone-responsive Vst1 fragment. These results are consistent with an involvement of WRKY proteins in ozone-induced phytoalexin gene expression.
Ca2+ /CAMP response element binding protein (CREB) is an important factor linking the opioid-regulated secondary messenger systems to alterations in gene expression. Opioids regulate CREB level, its phosphorylation and binding to its corresponding response element in the promoters of several genes implicated in drug addiction. CREB mediates the action of opioids on the expression of several genes in brain regions responsible for drug-seeking behavior and manifestation of signs of dependence. Moreover, alterations in CREB level can affect the rewarding properties of morphine and regulate the self-administration of cocaine. At the cellular level CREB acts as convergence point for different cellular pathways. Opioids affect two different intracellular mediator systems: inhibitory - connected with cAMP, and stimulatory - involving calcium and the PKC pathway. Both can affect CREB but in different phases of opiate action. The presence of this biphasic mechanism can explain the phenomenon of the induction of some CRE-controlled genes after both acute and chronic morphine administration. Cellular studies also highlight the relevance of other ATF/CREB family members which can affect Ca /cAMP response element (CRE) controlled transcription as well as other transcription factors which make the opioid induction longer lasting.
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