Dysregulated human renin expression in transgenic mice carrying truncated genomic constructs: evidence supporting the presence of insulators at the renin locus. Am J Physiol Renal Physiol 2008 Sep;295(3):F642-53
Date
07/18/2008Pubmed ID
18632798Pubmed Central ID
PMC2536869DOI
10.1152/ajprenal.00384.2007Scopus ID
2-s2.0-54449093668 (requires institutional sign-in at Scopus site) 3 CitationsAbstract
We previously generated transgenic mice carrying a large P1 artificial chromosome (PAC160) encompassing a 160-kb segment containing the human renin gene, two upstream genes, and one downstream gene. We also previously generated mutant PAC160 constructs lacking the distal enhancer and concluded it is required to maintain baseline expression of human renin, but is not required for tissue-specific, cell-specific, and regulated expression of renin in vivo. We now report two additional transgenic lines carrying random truncations of PAC160 upstream of the renin gene. Southern and PCR mapping studies indicate that the truncation break points in the two lines are located approximately 10.4 and 2.5 kb upstream of the renin gene causing a deletion of all DNA upstream of the break. We tested the hypothesis that large-scale deletion of DNA upstream of the human renin gene including the enhancer would cause dysregulation of human renin expression. Phenotypically, these truncations cause a severe dysregulation of human renin expression, but remarkably, a preservation of the normal tissue-specific expression of the human ethanolamine kinase 2 (ETNK2) gene which lies immediately downstream of renin. Several functional binding sites for CTCF, a mammalian insulator protein, were identified in and around the renin and ETNK2 loci by gel shift and chromatin immunoprecipitation. We conclude that there are sequences in and around the renin and ETNK2 loci which act as boundaries between neighboring genes which insulate them from each other. The study illustrates the value of taking a much wider genomic perspective when studying mechanisms regulating gene expression.
Author List
Zhou X, Weatherford ET, Liu X, Born E, Keen HL, Sigmund CDAuthor
Curt Sigmund PhD Chair, Professor in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBase Sequence
Binding Sites
CCCTC-Binding Factor
Chromosomes, Artificial, P1 Bacteriophage
DNA-Binding Proteins
Enhancer Elements, Genetic
Gene Expression Regulation
Genomics
Humans
Insulator Elements
Kisspeptins
Mice
Mice, Transgenic
Molecular Sequence Data
Phosphotransferases (Alcohol Group Acceptor)
Renin
Repressor Proteins
Transgenes
Tumor Suppressor Proteins
Vesicular Transport Proteins