Functional characterisation and expression analysis of recombinant serum amyloid P isoform 1 (RbSAP1) from rock bream (Oplegnathus fasciatus).
Lectins are carbohydrate-binding proteins that play important roles in the recognition and elimination of pathogens via the innate immune system. Pentraxins (PTX) are humoral lectins, which are multifunctional proteins in vertebrates. Pentraxins can be divided into two groups based on their primary structure: short (C-reactive protein and serum amyloid P [SAP]) and long pentraxins (PTX3 and neuronal pentraxins). Previously, SAP was shown to have Ca(2+)-dependent binding specificity for various ligands and to be a major acute phase protein. In this study, we identified and characterised the gene encoding SAP isoform 1 in rock bream (Oplegnathus fasciatus) (RbSAP1) and analysed its expression in various tissues after a pathogen challenge. An alignment analysis conducted based on the deduced amino acid sequence of RbSAP1 (1918 bp full-length cDNA with a 699 bp open reading frame encoding 232 amino acids) and SAPs and PTXs isolated from other organisms, revealed that the pentraxin domain and cysteine residues of the deduced protein are conserved. RbSAP1, which was ubiquitously expressed in all tissues examined, was predominantly detected in head kidney, trunk kidney, peripheral blood leukocytes, and gills. RbSAP1 expression was dramatically up-regulated in the kidney and liver after infection with Edwardsiella tarda, Streptococcus iniae, or red seabream iridovirus. Purified rRbSAP1 was able to bind Gram-negative bacteria, Gram-positive bacteria, and pathogen-associated molecular patterns. Interestingly, rRbSAP1 aggregated Gram-negative bacteria in the presence of Ca(2+). The anti-pathogen activity of rRbSAP1 suggests that SAP functions in innate immunity in the rock bream.
Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea.
Kwang-Min
KM
Choi
College of Pharmacy, Duksung Women's University, 33, Samyang-ro 144-gil, Dobong Gu, Seoul 132-714, Republic of Korea.
Sang Hee
SH
Shim
Biotechnology Research Division, National Fisheries Research and Development Institute, 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 619-705, Republic of Korea.
Cheul Min
CM
An
Biotechnology Research Division, National Fisheries Research and Development Institute, 216 Gijanghaean-ro, Gijang-eup, Gijang-gun, Busan, 619-705, Republic of Korea.
Bo-Hye
BH
Nam
Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea.
Ji-Min
JM
Jeong
Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea.
Ju-Won
JW
Kim
Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea. Electronic address: vinus96@hanmail.net.
Chan-Il
CI
Park
D000595:Amino Acid Sequence; D000818:Animals; D018407:Bacterial Physiological Phenomena; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D017994:Iridovirus / Q000502:physiology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010473:Perciformes / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D000683:Serum Amyloid P-Component / Q000235:genetics* / Q000378:metabolism
D018076:DNA, Complementary; D029941:Fish Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D000683:Serum Amyloid P-Component
Innate immunity; Oplegnathus fasciatus; Pentraxin; Serum amyloid P