Source: ImmunoDB
http://cegg.unige.ch/insecta/immunodb/

GALEs: Galactoside-Binding Lectins
Summary

Zhiyong Xi and George Dimopoulos 

Department of Molecular Microbiology and Immunology, Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, 615 N. Wolfe street, Baltimore, MD 21205-2179, USA 

Galectins are thiol-dependent, beta-galactoside-binding lectins. Evidence has shown that GALEs are implicated in innate immunity in both Dm and Ag. DmGALEs composed of 2 carbohydrate recognition domains (CRDs) connected by a peptide link (tandem repeat type) [Pace & Baum 2004]. The absence of putative transmembrane domain and a classical secretion signal peptide implies DmGALEs are secreted by a non-classical secretion pathway [Pace & Baum 2004]. In vitro experiments had demonstrated the ability of DmGALEs to bind beta-galactoside sugars [Pace et al. 2002]. It is possible that DmGALEs participate in the innate immune system of the fly by facilitating microbial recognition and/or phagocytosis. AgGALEs contained only one CRD (prototype), and was found to be up-regulated in the salivary glands and gut of Anopheles mosquitoes that were infected with malaria or bacteria [Dimopoulos et al. 1996; Dimopoulos et al. 1998; Dimopoulos et al. 2001]. It was proposed that AgGALEs might function as PRRs by binding saccharide ligands on the microbial surface to trigger a host immune response, or agglutinate and opsonize bacteria in the midgut following blood-feeding [Dimopoulos et al. 2001]. In Fig S8, three 1:1:1 orthologous trios, and one mosquito-specific 1:1 orthologous pair can be identified, as well as possible recent duplications in Aa to form GALE6A/B and GALE8A/B. A more divergent group of GALEs consists of one Dm (CG14879), one Ag (GALE10), and three Aa (GALE12/13/14) GALEs. The conserved GALEs (shared by different insects) are most likely to play roles in processes such as cell fate determination and cell proliferation.