The evolutionary conservation of the NF-kappaB transcription factors, from Drosophila to humans, underscores its pivotal role in immune response. Unexpectedly, the canonical NF-kappaB signaling pathway is not functional in the immune system of Caenorhabditis elegans. Therefore, the ancient origin of the NF-kappaB signaling pathway is still unknown. Here, we report the discovery and characterization of a primitive and functional NF-kappaB/IkappaB pathway in the immune defense of a "living fossil," the horseshoe crab, Carcinoscorpius rotundicauda. The ancient NF-kappaB/IkappaB homologues, CrNFkappaB, CrRelish, and CrIkappaB, share numerous signature motifs with their vertebrate orthologues. CrNFkappaB recognizes both horseshoe crab and mammalian kappaB response elements. CrIkappaB interacts with CrNFkappaB and inhibits its nuclear translocation and DNA-binding activity. The activation of the CrNFkappaB is autoregulated by a feedback mechanism mediated by CrIkappaB, the natural inhibitor of CrNFkappaB. We further show that Gram-negative bacteria infection causes rapid degradation of CrIkappaB and nuclear translocation of CrNFkappaB. Infection also leads to an increase in the kappaB-binding activity and up-regulation of immune-related gene expression, like inducible nitric oxide synthase and Factor C, an LPS-activated serine protease. Altogether, our study shows that, although absent in C. elegans, the NF-kappaB/IkappaB signaling cascade remains well conserved from horseshoe crab to humans, playing an archaic but fundamental role in regulating the expression of critical immune defense molecules.
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http://dx.doi.org/10.1073/pnas.0507044103 | DOI Listing |
J Zoo Wildl Med
December 2024
National Aquarium, Baltimore, MD 21202, USA.
Serial health assessment of a managed population of American horseshoe crabs (HSC; ) was performed. Twenty HSC were examined once a month for 7 mon; this included a physical exam with a standardized scoring sheet, HR, morphometrics, and hemolymph evaluation with hemocyte count, copper concentration, and biochemistry panel. The HSC in this population had varying levels of external lesions at enrollment.
View Article and Find Full Text PDFAquat Toxicol
December 2024
South China Sea Fisheries Research Institute, Chinese Academy of Fisheries Sciences, Guangzhou 510300, China; Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs of China, Guangzhou 510300, China; Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou 510300, China; Sanya Tropical Fisheries Research Institute, Sanya, Hainan 572019, China. Electronic address:
Mercury (Hg) contamination is a major environmental concern that continuously impacts marine organisms, including the mangrove horseshoe crab (Carcinoscorpius rotundicauda). As a vulnerable species, C. rotundicauda holds significant ecological and evolutionary value, making it particularly susceptible to Hg pollution and deserving of focused conservation efforts.
View Article and Find Full Text PDFTalanta
December 2024
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, Yunnan, PR China. Electronic address:
Endotoxins are found in the outer membrane of all gram-negative bacteria and are a primary cause of endotoxemia, organ failure, and significant harm to human health. Limulus reagent as traditional detection method has certain limitations for the rapid and accurate detection of endotoxin due to the high costs associated with the horseshoe crab used in the sensing process. Herein, a fluorometric and colorimetric dual-mode biosensor was prepared for the rapid and sensitive detection of endotoxin.
View Article and Find Full Text PDFArch Microbiol
November 2024
Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, 65000, Thailand.
Fish Shellfish Immunol
January 2025
Key Lab of Freshwater Animal Breeding, Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address:
Antibacterial peptide (AMP) is a crucial component of the innate immune system in most organism, play an important role in host defense processes. Many of these peptides have broad antimicrobial activity against Gram-negative, -positive bacteria and fungi. In the present study, a novel AMP named CpAMP was identified using transcriptome analysis in Chinese horseshoe crab.
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