Identification and expression analysis of a novel R-type lectin from the coleopteran beetle, Tenebrio molitor

Abstract We have identified novel ricin-type (R-type) lectin by sequencing of random clones from cDNA library of the coleopteran beetle, Tenebrio molitor . The cDNA sequence is comprised of 495 bp encoding a protein of 164 amino acid residues and shows 49% identity with galectin of Tribolium castaneum . Bioinformatics analysis shows that the amino acid residues from 35 to 162 belong to ricin-type beta-trefoil structure. The transcript was significantly upregulated after early hours of injection with peptidoglycans derived from Gram (+) and Gram (−) bacteria, beta-1, 3 glucan from fungi and an intracellular pathogen, Listeria monocytogenes suggesting putative function in innate immunity.