Avtor/Urednik     Debeljak, Maruša
Naslov     Uravnavanje izražanja gena za kapa kazein ( kapa-CN) pri govedu
Prevedeni naslov     Regulation of the bovine kappa casein (kappa-CN) gene expression
Tip     monografija
Kraj izdaje     Ljubljana
Založnik     Medicinska fakulteta
Leto izdaje     2002
Obseg     str. 144
Jezik     slo
Abstrakt     The structure of the bovine kappa-casein gene and its genetic variation within the coding region have been previously described. However, little is known about the molecular mechanisms involved in the regulation of expression of this gene. Expression of most milk protein genes is regulated by pituitary hormone prolactin. The prolactin signal is processed through the StatS pathway to the nucleus. Transcription from the bovine kappa-casein gene promoter is induced by lactogenic hormones (prolactin, hydrocortisone and insulin) in the bovine mammary epithelial cell line, BME-UV 1/2. In order to test the promoter activity we transfected BME-UV 1/2 cell line with the luciferase reporter gene construct containing short (925 bp) and long (2064 bp) version of the kappa-casein promoter. In the luciferase assay very low expression level was found after transfection with the short promoter variant, the longer promoter fragment also induced weak but specific expression suggesting that 2064 bp of the bovine kappa-casein promoter are sufficient for induction of expression under in vitro conditions. The analysis of known promoter region revealed several potential binding sites for transcription factors, which are involved in regulation of lactoprotein genes (Stat5, GRE, C/EBP, YY1 in NF 1). Due to important role of the Stat5 in regulation of lactoprotein gene expression we focused on the functionality of the Stat5 binding sites in the bovine kappa-casein promoter. Using electro mobility shift and Dnase I protection assay we were able to identify four binding sites for Stat5 factor in the bovine kappa-casein promoter (-1226/-1218, -1130/-1122, -1028/-1020 and -441/-434). Our results suggest that important regulator of the bovine kappa-casein gene expression lies in the region between -2064 and -925 and forms an enhancer element. (Abstract truncated at 2000 characters).
Deskriptorji     CASEINS