Differential expression of AP-2gamma and AP-2alpha during human trophoblast differentiation

Life Sci. 2001 Sep 21;69(18):2157-65. doi: 10.1016/s0024-3205(01)01299-1.

Abstract

Previous studies from our laboratory demonstrated that AP-2alpha induces the expression of the hPL and hCG genes in cultured trophoblast cells. In the current study, we have shown by transient transfection studies that AP-2gamma, which is the product of a separate gene from AP-2alpha, also stimulates hPL and hCGbeta promoter activities. However, AP-2gamma mRNA levels during in vitro differentiation of human cytotrophoblast cells were strikingly different than those of AP-2alpha mRNA levels, with AP-2alpha increasing and AP-2gamma markedly decreasing during the differentiation process. The amount of AP-2gamma protein binding to AP-2 elements on the hPL promoter, as determined by supershift assays, also markedly decreased during the differentiation process. These findings strongly suggest that AP-2gamma action in cytotrophoblast cells is repressed by a co-factor(s) that inhibits AP-2gamma action or is prevented by the absence of a co-factor(s) that is essential for AP-2gamma action.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Differentiation
  • Cells, Cultured
  • DNA-Binding Proteins / biosynthesis*
  • Female
  • Gene Expression Regulation, Developmental
  • Humans
  • Pregnancy
  • Transcription Factor AP-2
  • Transcription Factors / biosynthesis*
  • Trophoblasts / cytology
  • Trophoblasts / metabolism*

Substances

  • DNA-Binding Proteins
  • TFAP2A protein, human
  • TFAP2C protein, human
  • Transcription Factor AP-2
  • Transcription Factors