|
Originally published In Press as doi:10.1074/jbc.M306641200 on August 29, 2003
J. Biol. Chem., Vol. 278, Issue 49, 49428-49437, December 5, 2003
Transcriptional Regulation of Limulus Factor C
REPRESSION OF AN NF B MOTIF MODULATES ITS RESPONSIVENESS TO BACTERIAL LIPOPOLYSACCHARIDE*
Lihui Wang ,
Bow Ho , and
Jeak Ling Ding ¶
From the
Departments of Biological Sciences and Microbiology, National University of Singapore, 14 Science Drive 4, Singapore 117543
Serine proteases play fundamental roles in invertebrate development, hemostasis, and innate immunity. This is exemplified by the limulus Factor C, which is a serine protease that binds a pathogen-associated molecule, lipopolysaccharide (LPS) to trigger a blood coagulation cascade. As a central molecule in the limulus innate immunity and hemostasis, Factor C gene expression has been detected in two major immune defense tissues, the amebocytes and hepatopancreas. Infection of the limulus with live Gram-negative bacteria induces a 23-fold increase in mRNA transcripts in both tissues. However, in vitro studies in Drosophila cell lines using Factor C promoter-reporter chimera DNA constructs, and site-directed mutagenesis of the promoter demonstrated that a proximal B binding site, aided by an adjacent dorsal-like binding motif responds dramatically to LPS and dorsal transcription factor overexpression. Electrophoretic mobility shift assay further confirmed a strong interaction of the limulus B motif with Rel proteins. However, deletion constructs of the Factor C promoter harboring different numbers of dorsal-like binding sites upstream of the B motif as well as the electrophoretic mobility shift assay of these motifs with Rel proteins strongly suggest that the up-regulation of Factor C gene expression is attenuated during microbial challenge. The repression of the dramatic activation of this pathogen-responsive gene by LPS is probably effected via competition between the dorsal-like motifs over the proximal LPS-responsive B unit, or through inhibition from the upstream repressive element(s), which accounts for the gene expression pattern observed in vivo. Our findings demonstrate that blood coagulation and innate immune response are integrated at the transcriptional level in this ancient organism, and that this LPS-responsive serine protease is controlled by an evolutionarily conserved NF B pathway.
Received for publication, June 23, 2003
, and in revised form, August 22, 2003.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBankTM/EBI Data Bank with accession number(s) AF517565 and S77063.
* This work was supported by the Agency for Science Technology and Research, A*STAR, Grant LS/99/004 (to J. L. D. and B. H.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
¶ To whom correspondence should be addressed: Dept. of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543. Tel.: 65-68742776; Fax: 65-67792486; E-mail: dbsdjl{at}nus.edu.sg.

CiteULike Complore Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
Z. H. Fan, X. W. Wang, J. Lu, B. Ho, and J. L. Ding
Elucidating the Function of an Ancient NF-{kappa}B p100 Homologue, CrRelish, in Antibacterial Defense
Infect. Immun.,
February 1, 2008;
76(2):
664 - 670.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. W. Wang, N. S. Tan, B. Ho, and J. L. Ding
Evidence for the ancient origin of the NF-{kappa}B/I{kappa}B cascade: Its archaic role in pathogen infection and immunity.
PNAS,
March 14, 2006;
103(11):
4204 - 4209.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. S. T. Ong, Lihui Wang, Yong Zhu, B. Ho, and Jeak Ling Ding
The response of ferritin to LPS and acute phase of Pseudomonas infection
Innate Immunity,
October 1, 2005;
11(5):
267 - 280.
[Abstract]
[PDF]
|
 |
|
Copyright © 2003 by the American Society for Biochemistry and Molecular Biology.
|
Advertisement
Advertisement
|