Transcription factor Sp1 has been implicated in the expression of many genes. Moreover, it has been suggested that Sp1 is linked to the maintenance of methylation-free CpG islands, the cell cycle, and the formation of active chromatin structures. We have inactivated the mouse Sp1 gene. Sp1-/- embryos are retarded in development, show a broad range of abnormalities, and die around day 11 of gestation. In Sp1-/- embryos, the expression of many putative target genes, including cell cycle-regulated genes, is not affected, CpG islands remain methylation free, and active chromatin is formed at the globin loci. However, the expression of the methyl-CpG-binding protein MeCP2 is greatly reduced in Sp1-/- embryos. MeCP2 is thought to be required for the maintenance of differentiated cells. We suggest that Sp1 is an important regulator of this process.

0 (DNA Primers), 0 (Transcription Factor, Sp1), Animals, Base Sequence, Cell Differentiation/genetics/physiology, Cell Division/genetics/physiology, Chimera, CpG Islands, DNA Methylation, DNA Primers/genetics, Embryo and Fetal Development/genetics/*physiology, Female, Gene Targeting, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Pregnancy, Support, Non-U.S. Gov't, Transcription Factor, Sp1/genetics/*physiology,
Erasmus MC: University Medical Center Rotterdam

Marin, M, Karis, A, Visser, P, Grosveld, F.G, & Philipsen, J.N.J. (1997). Transcription factor Sp1 is essential for early embryonic development but dispensable for cell growth and differentiation. Cell, 89(4), 619–628. doi:10.1016/S0092-8674(00)80243-3