Xenbase Image ID: 79990

Fig. 2. Dominant-negative forms of CREB. (A) Schematic representation of the CREB constructs used for injection experiments. Full length constitutive dominant-negative CREBA133 and leucine zipper mutant CREBDA133, respectively, were fused to the ligand binding domain of the human progesterone receptor, which contains the C-terminal truncation D892-933 and is, thus, responsive only to the agonist RU486. (B) Transfection experiments showing that CREBA133PR inhibits CRE-mediated transcription in a RU486-dependent and dose-dependent manner. CAT activity is expressed as percentage of the maximal activity induced by wild-type CREB. Diagram represents the average of three independent experiments. (C) Western blot analysis to determine CREBA133PR protein levels in injected embryos. CREBA133PR mRNA was injected into every cell of 4-cell stage embryos. Embryos were grown until the stage indicated and lysed. An equivalent to two embryos was analyzed, and CREBA133PR protein was detected with anti-CREB antibodies. A strong band at the expected size of 60 kDa was observed in extracts of injected embryos, but not in uninjected control embryos. Abbreviations: bZIP, basic DNA-binding domain with leucine zipper; hPR-LBD, human progesterone receptor ligand binding domain; KID, kinase inducible domain containing serine 133 in wild-type CREB. Image published in: Lutz B et al. (1999) Copyright © 1999. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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