Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.10.1 (
ERK
)
95,504
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that is acutely induced by inflammatory stimuli, and the products of HO-1-mediated heme degradation have anti-inflammatory properties. In many different pathophysiologic states, the up-regulation of HO-1 has been shown to be beneficial in combating the detrimental consequences of increased inflammation. Ets transcription factors are known to be important mediators of inflammatory responses, and the ternary complex factor subfamily of Ets proteins has both transcriptional activation and repression activity. The present study demonstrates that of several ternary complex factor subfamily members, only
Elk
-3 represses HO-1 promoter activity in macrophages. Endotoxin administration to macrophages led to a dose-dependent decrease in endogenous
Elk
-3 mRNA levels, and this reduction in
Elk
-3 preceded the LPS-mediated up-regulation of HO-1 message. Analogous results also occurred in lung tissue of mice exposed to endotoxin. Two putative Ets binding sites (EBS1 and
EBS2
) are present in the downstream region of the murine HO-1 promoter (bp -125 and -93, respectively), and we recently showed that the
EBS2
site is essential for HO-1 induction by endotoxin. In contrast, the present study demonstrates that the repressive effect of
Elk
-3 on HO-1 promoter activity is dependent on the EBS1 site. Taken together, our data reveal that
Elk
-3 serves as an important repressor of HO-1 gene transcription and contributes to the tight control of HO-1 gene regulation in the setting of inflammatory stimuli.
...
PMID:Endotoxin-induced down-regulation of Elk-3 facilitates heme oxygenase-1 induction in macrophages. 1645