title: Identification of C-type lectin-domain proteins (CTLDPs) in silkworm Bombyx mori.
abstract: C-type lectins (CTLs) represent a large family of proteins that can bind carbohydrate moieties normally in a calcium-dependent manner. CTLs play important roles in mediating cell adhesion and the recognition of pathogens in the immune system. In the present study, we have identified 23 CTL genes in domestic silkworm Bombyx mori. CTL-domain proteins (CTLDPs) are classified into three groups based on the number of carbohydrate-recognition domains (CRDs) and the domain architectures. These include twelve CTL-S (Single-CRD), six immulectins (Dual-CRD) and five CTL-X (CRD with other domains). We studied their phylogenetic features, analyzed the conserved residues, predicted tertiary structures, and examined the tissue expression profile and immune inducibility. Through bioinformatics analysis, we have putatively identified ten secretory and two cytoplasmic CTL-S; four secretory and two cytoplasmic immulectins; one secretory, one cytoplasmic and three transmembrane forms of CTL-X. Most B. mori CTLDPs form monophyletic groups with orthologs from Lepidoptera, Diptera, Coleoptera and Hymenoptera species. Immulectins of B. mori and Manduca sexta evolved from common ancestor genes perhaps due to gene duplication events of CTL-S ancestor genes. Homology modeling revealed that the overall structures of B. mori CTL domains are analogous to those of humans with a variable loop region. We examined the expression profile of CTLDP genes in naïve and immune-stimulated tissues. The expression and induction of CTLDP genes were related to the tissues and microorganisms. Together, our gene identification, sequence comparison, phylogenetic analysis, homology modeling and expression analysis laid a good foundation for the further studies of B. mori CTLDPs and comparative genomics.
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Xiang-Jun
authors.initials: XJ
authors.lastname: Rao
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Toufeeq
authors.initials: T
authors.lastname: Shahzad
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Su
authors.initials: S
authors.lastname: Liu
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wu
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Yan-Ting
authors.initials: YT
authors.lastname: He
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Wei-Jia
authors.initials: WJ
authors.lastname: Sun
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Xiang-Yun
authors.initials: XY
authors.lastname: Fan
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Yun-Fan
authors.initials: YF
authors.lastname: Yang
authors.affiliation: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, PR China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Shi
authors.affiliation: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, USA. Electronic address: Yux@umkc.edu.
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D012831:Bombyx; D005786:Gene Expression Regulation; D006801:Humans; D007109:Immunity; D019476:Insect Proteins / Q000235:genetics*; D037181:Lectins, C-Type / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D051192:Receptors, Pattern Recognition / Q000235:genetics*; D040681:Structural Homology, Protein
chemical_list: D019476:Insect Proteins; D037181:Lectins, C-Type; D051192:Receptors, Pattern Recognition
keywords: C-type lectin; Carbohydrate recognition domain; Insect immunity