Distinct regulatory regions from the prolactin-like protein C variant promoter direct trophoblast giant cell versus spongiotrophoblast cell-specific expression.
PRL-like protein C variant (PLP-Cv) is a newly identified member of the PRL family. PLP-Cv is specifically expressed in the chorioallantoic placenta by two distinct cell populations: trophoblast giant cells and spongiotrophoblast cells. To gain some insight regarding the control of PLP-Cv gene expression and the regulatory factors controlling trophoblast giant cell and spongiotrophoblast cell lineages, we have initiated a structural and functional analysis of the PLP-Cv promoter. The activities of a series of PLP-Cv promoter constructs, ranging in size from 4.5 kb to 50 bp, ligated to a luciferase reporter have been assessed in the Rcho-1 trophoblast cell line (restricted to trophoblast giant cell differentiation) and in a primary spongiotrophoblast cell culture system after transient transfection. PLP-Cv promoter constructs containing 4.5 kb to 149 bp of 5'-flanking DNA possessed full activity in the trophoblast giant cell model. A region located between -149 and -124 bp upstream of the PLP-Cv transcription start site was found to be essential for activation of the PLP-Cv promoter. Spongiotrophoblast cells required additional PLP-Cv 5'-flanking DNA for full activity. A region located between -2518 and -2242 bp upstream of the PLP-Cv transcription start site significantly enhanced PLP-Cv promoter in spongiotrophoblast cells. In conclusion, mechanisms underlying the activation of the PLP-Cv promoter are different in trophoblast giant cells vs. spongiotrophoblast cells.
Dai
G
G
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City 66160, USA. gdai@kumc.edu
Wolfe
M W
MW
Soares
M J
MJ
D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000502:physiology*; D014644:Genetic Variation / Q000502:physiology*; D015726:Giant Cells / Q000502:physiology*; D006736:Horses / Q000097:blood; D008969:Molecular Sequence Data; D011257:Pregnancy Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013379:Substrate Specificity; D014327:Trophoblasts / Q000502:physiology*
D011257:Pregnancy Proteins; C502145:Prl8a3 protein, rat