Transcriptional Regulation of γ- and ε-Globin Genes
by Basic Krüppel-like Factor

( Beijing Institute
of Radiation Medicine, Beijing 100850, China; 1Department of Hematology,
First Hospital of Peking University, Beijing 100034, China )

Abstract
To study the transcription regulatory function of basic Krüppel-like
factor（BKLF）on γ- and ε-globin genes, recombinant expression vectors containing
the full-length human BKLF gene, and a deletion mutant that lost N-terminal
40 amino acids, were constructed and used, respectively, to transiently transfect
COS7 cells in order to assay their reporter activities. Results showed that
hBKLF was able to repress the activity of γ- and ε-globin gene promoters,
while the antisense nucleic acid specific for hBKLF activated the transcription
of these promoters. Deleting 40 amino acids from N-terminus did not influence
the transcriptional repression of hBKLF. The stimulatory function of FKLF
on γ- and ε-globin gene promoters was also significantly reduced by hBKLF.
In addition, BKLF bound the CACCC element in the SHP1 (SH2 containing protein
tyrosine phosphatase 1) gene promoter. These results suggest that γ- and ε-globin
genes may be transcriptional targets of BKLF, providing evidence for further
studies on the role of BKLF in participating the transcriptional regulation
of haemocyte specific genes.