Dual hereditary jaundice, a combination of Dubin-Johnson and Gilbert's syndromes, is a rare clinical entity resulting from the compound defects of bilirubin conjugation and transport. We aimed to study the hereditary jaundice in 56 members from seven seemingly unrelated Roma families, to find the causal genetic defect and to estimate its origin in Roma population. On the basis of biochemical results of total and conjugated serum bilirubin and clinical observations, ABCC2 gene, TATA box and phenobarbital enhancer (PBREM) of UGT1A1 gene were analyzed by sequencing, RFLP and fragment analysis. We found a novel variant c.1013_1014delTG in the eighth exon of ABCC2 gene in 17 individuals in homozygous state. Dual defect NG_011798.1:c.[1013_1014delTG]; NG_002601.2:g.[175492_175493insTA] in homozygous state was found in four subjects. Biochemical analyses of porphyrins and coproporphyrin isomers in urine performed by HPLC showed inverted ratio of excreted coproporphyrin, with the predominance of coproporphyrin I (up to 100%), typical for patients with Dubin-Johnson syndrome. Pursuant cultural and social specifics of the population led us to suspect a founder effect; therefore, we performed a haplotype study using genotyping data from Affymetrix Genome-Wide Human SNP Array 6.0. As a result, we detected a common 86 kbp haplotype encompassing promoter and part of the ABCC2 coding region among all families, and estimated the age of the ancestral variant to 178-185 years. In this study, we found a novel deletion in ABCC2 gene, described genetic and biochemical features of dual hereditary jaundice and confirmed the existence of founder effect and common haplotype among seven Roma families.
- MeSH
- bilirubin metabolismus MeSH
- delece genu * MeSH
- efekt zakladatele * MeSH
- Gilbertova nemoc diagnóza genetika MeSH
- glukuronosyltransferasa genetika MeSH
- haplotypy MeSH
- homozygot MeSH
- jednonukleotidový polymorfismus MeSH
- koproporfyriny moč MeSH
- lidé MeSH
- polymorfismus délky restrikčních fragmentů MeSH
- proteiny spojené s mnohočetnou rezistencí k lékům genetika MeSH
- TATA box MeSH
- žloutenka chronická idiopatická diagnóza genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Acetyl-CoA:α-glucosaminide N-acetyltransferase (N-acetyltransferase) is a lysosomal membrane enzyme that catalyzes a key step in the lysosomal degradation of heparan sulfate. Its deficiency causes Sanfilippo syndrome type IIIC (Mucopolysaccharidosis type IIIC, MPS IIIC). Here we characterize the promoter region of HGSNAT, the gene encoding N-acetyltransferase, which is located in the pericentromeric region of chromosome 8. We show that HGSNAT transcription is driven by a TATA-less promoter whose key elements are contained within the 1054bp region upstream of exon 1. About 400 bases of the region's 3'-prime end overlap with an unmethylated CpG island. Reduced reporter activities from promoter serial deletion constructs suggested strong regulatory elements at positions -101 to -20bp and -1073 to -716bp of the downstream initiation codon (DS-ATG). Targeted mutagenesis of the first Specificity protein 1-A (Sp1-A) of the six in silico-predicted Sp1 sites in the region flanking the major transcription start sites (TSSs, +50/-101) led to a 55% decrease of reporter activity, while inactivation of each of Sp1-B and Sp1-C resulted in its almost two-fold increase. The binding of Sp1 to the region was confirmed by chromatin immunoprecipitation (ChIP). Overall, this confirms that Sp1 is important for regulation of the HGSNAT promoter. Promoter fragments in antisense orientation (constructs pGL4 -20/-1305 and pGL4 +50/-1305) led to reporter activities of about 50% of the pGL4 -1305/-20 activity, implying divergent initiation of transcription at the promoter. We identified two main TSSs at positions +1 and -15 from DS-ATG using Rapid amplification of cDNA ends (5'RACE). Transcripts initiating at the TSSs thus contain only DS-ATG. Five patients from our MPS IIIC cohort (n=23) carried the rs4523300 promoter variant and one the rs149596192 promoter variant. Both variants lowered the expression of the reporter down to 68% and 59%, respectively. However, white blood cell (WBC) N-acetyltransferase activities in individuals carrying the variants did not significantly differ from homozygotes for the wild-type alleles, suggesting only a partial impact of transcriptional regulation on N-acetyltransferase activities in vivo.
- MeSH
- acetyltransferasy genetika MeSH
- buňky Hep G2 MeSH
- jednonukleotidový polymorfismus * MeSH
- lidé MeSH
- mukopolysacharidóza III genetika MeSH
- počátek transkripce * MeSH
- studie případů a kontrol MeSH
- TATA box * MeSH
- transkripční faktor Sp1 metabolismus MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Normal human B lymphocytes are sensitive to the growth-inhibitory action of TGF-beta1 whereas malignant B lymphoma cells are mostly resistant to TGF-beta1 effects. We have shown in our previous work that, TGF-beta1 treatment resulted in significant growth inhibition of the DoHH2 cell line. In the present study we showed that TGF-beta1-induced growth arrest was associated with notable downregulation of the myc-binding protein-1 (MBP-1). Moreover, our results indicated that c-Myc overexpression in TGF-beta1-arrested malignant B cells is mediated by binding of MBP-1, as a transcription repressor, to the (+118/+153) element of the promoter region of the myc gene.
- MeSH
- 2D gelová elektroforéza metody využití MeSH
- financování organizované využití MeSH
- folikulární lymfom genetika imunologie MeSH
- polymerázová řetězová reakce metody využití MeSH
- promotorové oblasti (genetika) MeSH
- protoonkogenní proteiny c-myc genetika imunologie MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody využití MeSH
- TATA box genetika imunologie MeSH
- transformující růstový faktor beta1 genetika imunologie MeSH
- western blotting metody využití MeSH
- MeSH
- diagnostické techniky molekulární metody MeSH
- dítě MeSH
- Gilbertova nemoc diagnóza genetika MeSH
- glukuronosyltransferasa fyziologie genetika MeSH
- hyperbilirubinemie diagnóza etiologie MeSH
- lidé MeSH
- mutace MeSH
- polymorfismus genetický MeSH
- TATA box genetika MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- přehledy MeSH
