A 5
Regulatory Sequence Containing Two Ets Motifs Controls
the Expression of the Wiskott-Aldrich Syndrome Protein (WASP) Gene
in Human Hematopoietic Cells
A. Petrella,
I. Doti,
V. Agosti,
P. Carandente Giarrusso,
D. Vitale,
H.M. Bond,
C. Cuomo,
P. Tassone,
B. Franco,
A. Ballabio,
S. Venuta, and
G. Morrone
From the Department of Experimental and Clinical Medicine, Faculty of
Medicine, Catanzaro, Italy; CEINGE Advanced Biotechnology, Naples,
Italy; the Department of Biochemistry and Medical Biotechnology,
University Federico II, Naples, Italy; the Istituto Nazionale Tumori
Fondazione Pascale, Naples, Italy; and the Telethon Institute for
Genetics and Medicine, Milan, Italy.
The recently-identified Wiskott-Aldrich syndrome protein gene (WASP)
is responsible for the Wiskott-Aldrich X-linked immunodeficiency as
well as for isolated X-linked thrombocytopenia (XLT). To characterize the regulatory sequences of the WASP gene, we have isolated, sequenced and functionally analyzed a 1.6-Kb DNA fragment upstream of the WASP
coding sequence. Transfection experiments showed that this fragment is
capable of directing efficient expression of the reporter chloramphenicol acetyltransferase (CAT) gene in all human
hematopoietic cell lines tested. Progressive 5
deletions showed
that the minimal sequence required for hematopoietic-specific
expression consists of 137 bp upstream of the transcription start site.
This contains potential binding sites for several hematopoietic
transcription factors and, in particular, two Ets-1 consensus that
proved able to specifically bind to proteins present in nuclear
extracts of Jurkat cells. Overexpression of Ets-1 in HeLa resulted in
transactivation of the CAT reporter gene under the control of WASP
regulatory sequences. Disruption of the Ets-binding sequences by
side-directed mutagenesis abolished CAT expression in Jurkat cells,
indicating that transcription factors of the Ets family play a key role
in the control of WASP transcription.
Blood, Vol. 91 No. 12 (June 15), 1998:
pp. 4554-4560
© 1998 by The American Society of Hematology.
