TY - JOUR
T1 - Identification and characterization of a critical CP2-binding element in the human interleukin-4 promoter
AU - Casolaro, Vincenzo
AU - Keane-Myers, Andrea M.
AU - Swendeman, Steven L.
AU - Steindler, Corinna
AU - Zhong, Fengming
AU - Sheffery, Michael
AU - Georas, Steve N.
AU - Ono, Santa Jeremy
PY - 2000/11/24
Y1 - 2000/11/24
N2 - Expression of cytokine genes in T cells is thought to result from a complex network of antigen- and mitogen-activated transcriptional regulators. CP2, a factor homologous to Drosophila Elf-1 and previously found to be a critical regulator of several viral and cellular genes in response to developmental signals, is rapidly activated in T helper (Th) cells in response to mitogenic stimulation. Here we show that overexpression of CP2 enhances interleukin (IL)-4 promoter-driven chloramphenicol acetyltransferase expression, while repressing IL-2 promoter activity, in transiently transfected Jurkat cells. A CP2-protected element, partially overlapping the nuclear factor of activated T cell-binding P2 sequence, was required for IL-4 promoter activation in CP2-overexpressing Jurkat cells. This CP2-response element is the site of a cooperative interaction between CP2 and an inducible heteromeric co-factor(s). Mutation of conserved nucleotide contacts within the CP2-response element prevented CP2 binding and significantly reduced constitutive and induced IL-4 promoter activity. Expression of a CP2 mutant lacking the Elf-1-homology region of the DNA-binding domain inhibited IL-4 promoter activity in a dominant negative fashion in transiently transfected Jurkat cells. Moreover, overexpressed CP2 markedly enhanced, while its dominant negative mutant consistently suppressed, expression of the endogenous IL-4 gene in the murine Th2 cell line D10. Taken together, these findings point to CP2 as a critical IL-4 transactivator in Th cells.
AB - Expression of cytokine genes in T cells is thought to result from a complex network of antigen- and mitogen-activated transcriptional regulators. CP2, a factor homologous to Drosophila Elf-1 and previously found to be a critical regulator of several viral and cellular genes in response to developmental signals, is rapidly activated in T helper (Th) cells in response to mitogenic stimulation. Here we show that overexpression of CP2 enhances interleukin (IL)-4 promoter-driven chloramphenicol acetyltransferase expression, while repressing IL-2 promoter activity, in transiently transfected Jurkat cells. A CP2-protected element, partially overlapping the nuclear factor of activated T cell-binding P2 sequence, was required for IL-4 promoter activation in CP2-overexpressing Jurkat cells. This CP2-response element is the site of a cooperative interaction between CP2 and an inducible heteromeric co-factor(s). Mutation of conserved nucleotide contacts within the CP2-response element prevented CP2 binding and significantly reduced constitutive and induced IL-4 promoter activity. Expression of a CP2 mutant lacking the Elf-1-homology region of the DNA-binding domain inhibited IL-4 promoter activity in a dominant negative fashion in transiently transfected Jurkat cells. Moreover, overexpressed CP2 markedly enhanced, while its dominant negative mutant consistently suppressed, expression of the endogenous IL-4 gene in the murine Th2 cell line D10. Taken together, these findings point to CP2 as a critical IL-4 transactivator in Th cells.
UR - http://www.scopus.com/inward/record.url?scp=0034711276&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034711276&partnerID=8YFLogxK
U2 - 10.1074/jbc.M007086200
DO - 10.1074/jbc.M007086200
M3 - Article
C2 - 10973979
AN - SCOPUS:0034711276
VL - 275
SP - 36605
EP - 36611
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 47
ER -