title: Identification of an amphioxus intelectin homolog that preferably agglutinates gram-positive over gram-negative bacteria likely due to different binding capacity to LPS and PGN.
abstract: Intelectin is a recently described galactofuranose-binding lectin that plays a role in innate immunity in vertebrates. Little is known about intelectin in invertebrates, including amphioxus, the transitional form between vertebrates and invertebrates. We cloned an amphioxus intelectin homolog, AmphiITLN-like, coding 302 amino acids with a conserved fibrinogen-related domain (FReD) in the N-terminus and an Intelectin domain in the C-terminus. In situ hybridization in adult amphioxus showed that AmphiITLN-like transcripts were highly expressed in the digestive tract and the skin. Quantitative real-time PCR revealed that AmphiITLN-like is significantly up-regulated in response to Staphylococcus aureus challenge, but only modestly to Escherichia coli. In addition, recombinant AmphiITLN-like expressed in E. coli agglutinates Gram-negative and Gram-positive bacteria to different degrees in a calcium dependent manner. Recombinant AmphiITLN-like could bind lipopolysaccharide (LPS) and peptidoglycan (PGN), the major cell wall components of Gram-negative and Gram-positive bacteria, respectively, with a higher affinity to PGN. Our work identified and characterized for the first time an amphioxus intelectin homolog, and provided insight into the evolution and function of the intelectin family.
authors.affiliation: Marine Biotechnology Research Center, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Institute of Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jingye
authors.initials: J
authors.lastname: Zhang
authors.forename: Changcun
authors.initials: C
authors.lastname: Bai
authors.forename: Changqing
authors.initials: C
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Kailin
authors.initials: K
authors.lastname: Li
authors.forename: Haiqing
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiumin
authors.initials: X
authors.lastname: Du
authors.forename: Lijun
authors.initials: L
authors.lastname: Feng
mesh_terms: D000371:Agglutination; D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D043344:Chordata / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000378:metabolism*; D037102:Lectins / Q000235:genetics* / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D008969:Molecular Sequence Data; D010457:Peptidoglycan / Q000378:metabolism*; D010802:Phylogeny; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D016415:Sequence Alignment; D013211:Staphylococcus aureus / Q000187:drug effects; D015854:Up-Regulation
chemical_list: D000900:Anti-Bacterial Agents; D037102:Lectins; D008070:Lipopolysaccharides; D010457:Peptidoglycan; D011994:Recombinant Proteins; D002118:Calcium