NR ATEB
AU Sander,P.; Hamann,H.; Drögemüller,C.; Kashkevich,K.; Schiebel,K.; Leeb,T.
TI Bovine prion protein gene (PRNP) promoter polymorphisms modulate PRNP expression and may be responsible for differences in bovine spongiform encephalopathy susceptibility
QU The Journal of Biological Chemistry 2005 Nov 11; 280(45): 37408-14
PT journal article
AB The susceptibility of humans to the variant Creutzfeldt-Jakob disease is greatly influenced by polymorphisms within the human prion protein gene (PRNP). Similar genetic differences exist in sheep, in which PRNP polymorphisms modify the susceptibility to scrapie. However, the known coding polymorphisms within the bovine PRNP gene have little or no effect on bovine spongiform encephalopathy (BSE) susceptibility in cattle. We have recently found a tentative association between PRNP promoter polymorphisms and BSE susceptibility in German cattle (Sander, P., Hamann, H., Pfeiffer, I., Wemheuer, W., Brenig, B., Groschup, M., Ziegler, U., Distl, O., and Leeb, T. (2004) Neurogenetics 5, 19-25). A plausible hypothesis explaining this observation could be that the bovine PRNP promoter polymorphisms cause changes in PRNP expression that might be responsible for differences in BSE incubation time and/or BSE susceptibility. To test this hypothesis, we performed a functional promoter analysis of the different bovine PRNP promoter alleles by reporter gene assays in vitro and by measuring PRNP mRNA levels in calves with different PRNP genotypes in vivo. Two variable sites, a 23-bp insertion/deletion (indel) polymorphism containing a RP58-binding site and a 12-bp indel polymorphism containing an SP1-binding site, were investigated. Band shift assays indicated differences in transcription factor binding to the different alleles at the two polymorphisms. Reporter gene assays demonstrated an interaction between the two postulated transcription factors and lower expression levels of the ins/ins allele compared with the del/del allele. The in vivo data revealed substantial individual variation of PRNP expression in different tissues. In intestinal lymph nodes, expression levels differed between the different PRNP genotypes.
IN Die Autoren hatten schon in [APVR] eine statistisch signifikante Korrelation zwischen einer 23 Nukleotide langen Deletion bzw. Insertion in der Promoter-Region und der BSE-Empfänglichkeit gefunden. Nun untersuchten sie diese und eine weitere 12 Nukleotide lange Insertion/Deletion, indem sie Promoterregionen mit den unterschiedlichen Sequenzen vor ein Luciferase-Gen setzten, dessen Expression sich in vitro durch eine Farbstoffreaktion leicht quantifizieren ließ. Außerdem verglichen sie bei Kälbern verschiedener Genotypen die mRNA-Konzentrationen. Tatsächlich fanden sie unterschiedliche Transkriptionsfaktor-Bindungen und anhand des Reportergens mit der Promoterregion mit beiden Insertionen eine geringere Expression als mit der Promoterregion mit beiden Deletionen. Natürlich fanden die Autoren zusätzlich gewebespezifische Unterschiede hinsichtlich der Expresion des Prionproteins.
MH Alleles; Animals; Cattle; Encephalopathy, Bovine Spongiform/*genetics; Gene Expression Regulation/*genetics; Genetic Predisposition to Disease/*genetics; Genotype; Polymorphism, Genetic/*genetics; Prions/*genetics; Promoter Regions (Genetics)/*genetics; Protein Binding; Research Support, Non-U.S. Gov't; Transcription Factors/metabolism; Transcription Initiation Site
AD Institute for Animal Breeding and Genetics, University of Veterinary Medicine, Bunteweg 17p, 30559 Hannover, Germany.
SP englisch
PO USA
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