A minimal ankyrin promoter linked to a human γ-globin gene demonstrates erythroid specific copy number dependent expression with minimal position or enhancer dependence in transgenic mice
Journal of Biological Chemistry
In red blood cells ankyrin (ANK-1) provides the primary linkage between the erythrocyte membrane skeleton and the plasma membrane. We have previously demonstrated that a 271-bp 5'-flanking region of the ANK-1 gene has promoter activity in erythroid, but not non-erythroid, cell lines. To determine whether the ankyrin promoter could direct erythroid-specific expression in vivo, we analyzed transgenic mice containing the ankyrin promoter fused to the human (A)γ-globin gene. Sixteen of 17 lines expressed the transgene in erythroid cells indicating nearly position-independent expression. We also observed a significant correlation between the level of Ank/(A)γ-globin mRNA and transgene copy number. The level of Ank/(A)γ mRNA averaged 11% of mouse α-globin mRNA per gene copy at all developmental stages. The addition of the HS2 enhancer from the β-globin locus control region to the Ank/(A)γ-globin transgene resulted in Ank/(A)γ-globin mRNA expression in embryonic and fetal erythroid cells in six of eight lines but resulted in absent or dramatically reduced levels of Ank/ (A)γ-globin mRNA in adult erythroid cells in eight of eight transgenic lines. These data indicate that the minimal ankyrin promoter contains all sequences necessary and sufficient for erythroid-specific, copy number-dependent, position-independent expression of the human (A)γ-globin gene.
Sabatino, D., Wong, C., Cline, A., Pyle, L., Garrett, L., Gallagher, P., & Bodine, D. (2000). A minimal ankyrin promoter linked to a human γ-globin gene demonstrates erythroid specific copy number dependent expression with minimal position or enhancer dependence in transgenic mice. Journal of Biological Chemistry, 275 (). http://dx.doi.org/10.1074/jbc.M004043200