title: Functional characterization of avidins in amphioxus Branchiostoma japonicum: Evidence for a dual role in biotin-binding and immune response.
abstract: Avidin is well known for its high affinity to biotin and has been found in many egg-laying vertebrate species. However, little is known about avidin in invertebrate species to date. Here we clearly showed the presence of two avidin genes, Bjavidin1 and Bjavidin2, in the amphioxus Branchiostoma japonicum, the first ones in non-vertebrate animals. We also showed that the expression of both Bjavidin1 and Bjavidin2 were inducible by progesterone, LTA and LPS. Moreover, we demonstrated for the first time that in addition to biotin-binding, the recombinant proteins rBjAVIDIN1 and rBjAVIDIN2 were not only able to interact with Gram-positive and negative bacteria as well as their conserved surface components LTA and LPS but also to enhance phagocytosis of bacteria by macrophages, suggesting that BjAVIDIN1 and BjAVIDIN2 both function as pattern recognition receptors and opsonins. It is thus clear that avidin may play a dual role in biotin-binding and immune response.
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Jiajing
authors.initials: J
authors.lastname: Xin
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Guangdong
authors.initials: G
authors.lastname: Ji
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China. Electronic address: gaozhan@ouc.edu.cn.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Department of Marine Biology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China. Electronic address: sczhang@ouc.edu.cn.
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001360:Avidin / Q000276:immunology*; D001710:Biotin / Q000378:metabolism; D002478:Cells, Cultured; D007113:Immunity, Innate; D064175:Lancelets / Q000276:immunology*; D037102:Lectins / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D009895:Opsonin Proteins / Q000096:biosynthesis; D010587:Phagocytosis; D010802:Phylogeny; D011374:Progesterone / Q000276:immunology; D011485:Protein Binding; D051192:Receptors, Pattern Recognition / Q000276:immunology*
chemical_list: D037102:Lectins; D008070:Lipopolysaccharides; D009895:Opsonin Proteins; D051192:Receptors, Pattern Recognition; C027112:fucose-binding lectin; D001360:Avidin; D011374:Progesterone; D001710:Biotin
keywords: Amphioxus; Avidin; Biotin-binding; Branchiostoma; Immune response