Structural features, evolutionary relationships, and transcriptional regulation of C-type lectin-domain proteins in Manduca sexta. (July 2015)

• Record Type: Journal Article
• Authors: Rao, Xiang-Jun; Cao, Xiaolong; He, Yan; Hu, Yingxia; Zhang, Xiufeng; Chen, Yun-Ru; Blissard, Gary; Kanost, Michael R.; Yu, Xiao-Qiang; Jiang, Haobo
• Is Part Of: Insect biochemistry and molecular biology. Volume 62(2015:Jul.)
• Page Start: 75
• Page End: 85
• Publication Date: 2015-07
• Subjects: Insect immunity -- Pattern recognition -- Carbohydrate recognition domain -- Expression profiling -- Comparative genomics; CTL C-type lectin -- CRD carbohydrate recognition domain -- CTLDP CTL-domain protein -- IML immulectin -- LC low complexity -- proPO prophenoloxidase -- MBL rat mannose binding lectin -- FPKM fragments per kilobase of exon per million fragments mapped -- C control -- I induced -- F fat body -- H hemocytes -- TM transmembrane -- SR scavenger receptor; Insect biochemistry -- Periodicals; Insects -- Physiology -- Periodicals; Insects -- Molecular aspects -- Periodicals; Biochemistry -- Periodicals; Insectes -- Biochimie -- Périodiques; Insectes -- Composition -- Périodiques; Insectes -- Physiologie -- Périodiques; Insectes -- Aspect moléculaire -- Périodiques; Biochimie -- Périodiques; Biochemistry; Insect biochemistry; Insects -- Molecular aspects; Insects -- Physiology; Periodicals; 572.8157
• DOI: 10.1016/j.ibmb.2014.12.006
• Languages: English
• ISSNs: 0965-1748

Abstract

Abstract: C-type lectins (CTLs) are a large family of Ca 2+ -dependent carbohydrate-binding proteins recognizing various glycoconjugates and functioning primarily in immunity and cell adhesion. We have identified 34 CTLDP (for CTL-domain protein) genes in the Manduca sexta genome, which encode proteins with one to three CTL domains. CTL-S1 through S9 (S for simple) have one or three CTL domains; immulectin-1 through 19 have two CTL domains; CTL-X1 through X6 (X for complex) have one or two CTL domains along with other structural modules. Nine simple CTLs and seventeen immulectins have a signal peptide and are likely extracellular. Five complex CTLs have both an N-terminal signal peptide and a C-terminal transmembrane region, indicating that they are membrane anchored. Immulectins exist broadly in Lepidoptera and lineage-specific gene duplications have generated three clusters of fourteen genes in the M. sexta genome, thirteen of which have similar expression patterns. In contrast to the family expansion, CTL-S1∼S6, S8, and X1∼X6 have 1:1 orthologs in at least four lepidopteran/dipteran/coleopteran species, suggestive of conserved functions in a wide range of holometabolous insects. Structural modeling suggests the key residues for Ca 2+ -dependent or independent binding of certain carbohydrates by CTL domains. Promoter analysis identified putative κB motifs in eighteen of the CTL genes, which did not have a strong correlation with immune inducibility in the mRNA or protein levels. Together, the gene identification, sequence comparisons, structure modeling, phylogenetic analysis, and expression profiling establish a solid foundation for future studies of M. sexta CTL-domain proteins. Graphical abstract: Highlights: Identified 9 simple and 6 complex CTL-domain proteins and 19 immulectins. Analyzed their structural features, evolution dynamics, and expression profiles. Modeled 56 CTL domains to predict their carbohydrate binding capability and specificity.