Molecular characterization of a bactericidal permeability-increasing protein/lipopolysaccharide-binding protein from black rockfish (Sebastes schlegelii): Deciphering its putative antibacterial role.
Bactericidal permeability-increasing protein (BPI)/lipopolysaccharide (LPS) binding proteins (LBPs) are well-known proteins that play an indispensable role in host antimicrobial defense. Herein, we report a homolog of BPI/LBP from black rockfish (Sebastes schlegelii) (designated as RfBPI/LBP) and characterize its structural and functional features at the molecular level. We identified the putative complete open reading frame (1422 bp) of RfLBP that encodes a 474 amino acid protein with a predicted molecular mass of ∼51.5 kDa. The primary protein sequence of RfBPI/LBP contains domain features of BPI/LBP family proteins and shares significant sequence consistency with its homologs. Our phylogenetic analysis clearly demonstrated the vertebrate ancestral origin of RfBPI/LBP, further reinforcing its evolutionary relationship with teleostean homologs. Recombinant RfBPI/LBP demonstrated in vitro LPS-binding activity and antibacterial activity against Escherichia coli, but not against Streptococcus iniae. Moreover, RfBPI/LBP exhibited temporal transcriptional activation against pathogens and pathogen-associated molecular patterns. Collectively, our findings suggest that RfBPI/LBP plays an essential role in host antimicrobial defense, plausibly through selective eradication of invading bacteria.
Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea.
Seongdo
S
Lee
Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea; Department of Zoology, University of Sri Jayewardenepura, Gangodawila, Nugegoda, 10250, Sri Lanka.
Don Anushka Sandaruwan
DAS
Elvitigala
Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea.
Sukkyoung
S
Lee
Genetics & Breeding Research Center, National Institute of Fisheries Science, Geoje, 53334, Republic of Korea.
Hyun Chul
HC
Kim
Graduate School of Medicine, Korea University, Ansan, Gyeonggido, 15355, Republic of Korea. Electronic address: hcpark67@korea.ac.kr.
Hae-Chul
HC
Park
Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea. Electronic address: jehee@jejunu.ac.kr.
Jehee
J
Lee
D000818:Animals; D000890:Anti-Infective Agents / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005399:Fishes / Q000276:immunology*; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000378:metabolism; D000069452:Pathogen-Associated Molecular Pattern Molecules / Q000276:immunology; D010802:Phylogeny; D011485:Protein Binding; D051192:Receptors, Pattern Recognition / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D029941:Fish Proteins; D008070:Lipopolysaccharides; D000069452:Pathogen-Associated Molecular Pattern Molecules; D051192:Receptors, Pattern Recognition; C021623:bactericidal permeability increasing protein
Antibacterial activity; Black rockfish; Immune stimulation; LBP/BPI; Transcriptional regulation