Potential autoregulation of transcription factor PU.1 by an upstream regulatory element.
Regulation of the hematopoietic transcription factor PU.1 (Spi-1) plays a critical role in the development of white cells, and abnormal expression of PU.1 can lead to leukemia. We previously reported that the PU.1 promoter cannot induce expression of a reporter gene in vivo, and cell-type-specific expression of PU.1 in stable lines was conferred by a 3.4-kb DNA fragment including a DNase I hypersensitive site located 14 kb upstream of the transcription start site. Here we demonstrate that this kb -14 site confers lineage-specific reporter gene expression in vivo. This kb -14 upstream regulatory element contains two 300-bp regions which are highly conserved in five mammalian species. In Friend virus-induced erythroleukemia, the spleen focus-forming virus integrates into the PU.1 locus between these two conserved regions. DNA binding experiments demonstrated that PU.1 itself and Elf-1 bind to a highly conserved site within the proximal homologous region in vivo. A mutation of this site abolishing binding of PU.1 and Elf-1 led to a marked decrease in the ability of this upstream element to direct activity of reporter gene in myelomonocytic cell lines. These data suggest that a potential positive autoregulatory loop mediated through an upstream regulatory element is essential for proper PU.1 gene expression.
Okuno
Yutaka
Y
Harvard Institutes of Medicine, Room 954, 77 Ave. Louis Pasteur, Boston, MA 02115, USA.
Huang
Gang
G
Rosenbauer
Frank
F
Evans
Erica K
EK
Radomska
Hanna S
HS
Iwasaki
Hiromi
H
Akashi
Koichi
K
Moreau-Gachelin
Francoise
F
Li
Youlin
Y
Zhang
Pu
P
Göttgens
Berthold
B
Tenen
Daniel G
DG
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D019070:Cell Lineage; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D022423:Myeloid Cells / Q000378:metabolism; D009928:Organ Specificity; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics*; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism*; D000099232:Proto-Oncogene Protein Spi-1
D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1