Evidence for a novel biological role for the multifunctional β-1,3-glucan binding protein in shrimp

beta-1,3-Glucan binding proteins (beta GBPs) are soluble pattern recognition proteins/receptors that bind to beta-1,3-glucans from fungi cell walls. In crustaceans, beta GBPs are abundant plasmatic proteins produced by the hepatopancreas, and have been proved to play multiple biological functions. Here, we purified and characterized novel members of the beta GBP family from the hemolymph of two Brazilian shrimps, Farfantepenaeus paulensis (Fp beta GBP) and Litopenaeus schmitti (Ls beta GBP). As observed for other crustacean species, Fp beta GBP and Ls beta GBP are monomeric proteins (similar to 100 kDa) able to enhance the activation of the prophenoloxidase system, a potent antimicrobial defense conserved in arthropods. More interestingly, we provided here evidence for a novel biological activity for shrimp beta GBPs: the agglutination of fungal cells. Finally, we investigated the modulation of the beta GBP gene in F. paulensis shrimps experimentally infected with a cognate fungal pathogen, Fusarium solani. From our expression data, beta GBP gene is constitutively expressed in hepatopancreas and not modulated upon a non-lethal fungal infection. Herein, we have improved our knowledge about the beta GBP family by the characterization of a novel biological role for this multifunctional protein in shrimp. (C) 2012 Elsevier Ltd. All rights reserved.