In vitro and in vivo effects of a multimerized alphas 1-casein enhancer on whey acidic protein gene promoter activity.
Experimental data obtained in previous works have led to postulate that enhancers increase the frequency of action of a linked promoter in a given cell and may have some insulating effects. The multimerized rabbit alpha s1-casein gene enhancer, the 6i multimer, was added upstream of the rabbit whey acidic protein gene (WAP) promoter (-6,300; +28 bp) fused to the firefly luciferase (luc) gene (6i WAP-luc construct). The 6i multimer increased reporter gene expression in mouse mammary HC11 cells. In transgenic mice, a very weak but significant increase was also observed. More noticeable, no silent lines were found when the 6i multimer was associated to the WAP-luc construct. This reflects the fact that the 6i multimer tends to prevent the silencing of the WAP-luc construct. After addition of the 5'HS4 insulator region from the chicken beta-globin locus upstream of the 6i multimer, similar luciferase levels were measured in 6i WAP-luc and 5'HS4 WAP-luc transgenic mice. Our present data and previous ones, which show that the 6i multimer has no insulating activity on a TK gene promoter construct indicate that the insulating activity of the 6i multimer is construct-dependent and not amplified by the 5'HS4 insulator.
Pantano
Thais
T
BioProtein Technologies, Paris, France.
Rival-Gervier
Sylvie
S
Prince
Sonia
S
Menck-Le Bourhis
Celeste
C
Maeder
Caroline
C
Viglietta
Céline
C
Houdebine
Louis-Marie
LM
Jolivet
Geneviève
G
D000818:Animals; D002364:Caseins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D046911:Macromolecular Substances; D051379:Mice; D008822:Mice, Transgenic; D008894:Milk Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D000067816:Whey Proteins
D002364:Caseins; D046911:Macromolecular Substances; D008894:Milk Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D000067816:Whey Proteins; D008156:Luciferases