Consensus AP-1 and CRE motifs upstream from the human cytotoxic serine
protease B (CSP-B/CGL-1) gene synergize to activate transcription
RD Hanson, JL Grisolano and TJ Ley
Division of Hematology/Oncology, Jewish Hospital, Washington University
Medical Center, St Louis, MO 63110.
The human CGL-1/cytotoxic serine protease B gene (CSP-B; also known as
granzyme B) is transcriptionally activated during cytotoxic T- lymphocyte
maturation. Activation can be mimicked in the PEER T-cell leukemia cell
line by treatment with 12-O-tetradecanoylphorbol-13- acetate (TPA) and
N6-2'-O-dibutyryladenosine 3',5'-cyclic monophosphate (bt2cAMP). In this
report, we show that a consensus AP-1 element and a consensus cAMP response
element (CRE) located 5' to the CSP-B transcriptional start site are both
required for transcriptional activation of the CPS-B promoter in TPA +
bt2cAMP-stimulated PEER cells. A 94-bp fragment containing both elements
activates a heterologous promoter in an orientation-independent fashion.
Several single nucleotide substitutions in the AP-1 site abolish activity
of the 94-bp fragment. Several point mutations in the consensus CRE
substantially reduce promoter activity, but one CRE mutation increases
activity fourfold. Replacement of the CRE with a second copy of the AP- 1
site results in a level of transcriptional activity comparable with that of
the wild-type sequence, but replacement of the AP-1 site with a CRE
abolishes activity. Neither the AP-1 site nor the CRE can be effectively
replaced with an SP-1 site. Deletions between the AP-1 site and the CRE
retain full activity only if helical spacing is preserved, suggesting that
synergism between these two elements is either the result of cooperative
binding of factors to the DNA or of cooperative binding of DNA-bound
factors to another protein.
Volume 82,
Issue 9,
pp. 2749-2757,
11/01/1993
Copyright © 1993 by The American Society of Hematology
