Characterization of a Novel Drosophila melanogasterGalectin

Abstract

We have cloned and characterized the first galectin to be identified in Drosophila melanogaster. The amino acid sequence of Drosophila galectin showed striking sequence similarity to invertebrate and vertebrate galectins and contained amino acids that are crucial for binding ␤-galactoside sugars. Confirming its identity as a galectin family member, the Drosophila galectin bound ␤-galactoside sugars. Structurally, the Drosophila galectin was a tandem repeat galectin containing two carbohydrate recognition domains connected by a unique peptide link. This divalent structure suggests that like mammalian galectins, Drosophila galectin may mediate cell-cell communication or facilitate cross-linking of receptors to trigger signal transduction events. The Drosophila galectin was very abundant in embryonic, larval, and adult Drosophila. During embryogenesis, Drosophila galectin had a unique and specific tissue distribution. Drosophila galectin expression was concentrated in somatic and visceral musculature and in the central nervous system. Similar to other insect lectins, Drosophila galectin may function in both embryogenesis and in host defense. Drosophila galectin was expressed by hemocytes, circulating phagocytic cells, suggesting a role for Drosophila galectin in the innate immune system.

Up-regulation of Neurohemerythrin Expression in the Central Nervous System of the Medicinal Leech, Hirudo medicinalis, following Septic Injury

“…PCRs were performed in 50-l mixtures containing 2 l of firststrand cDNA as a template in PCR buffer 1ϫ (Q-Biogene), 1 l of primer, and 1 l of oligo d(T) [12][13][14][15][16][17][18] , each dNTP at 200 M, and 1 unit of TaqDNA polymerase (PerkinElmer Life Sciences). The PCR condition involves initial heating at 94°C for 5 min followed thereafter by 30 cycles of denaturation at 94°C for 40 s, primer annealing at 50°C for 1 min, and primer extension at 72°C for 1 min.…”

“…First-strand cDNAs were prepared from these total RNAs with oligo(dT) [12][13][14][15][16][17][18] for primer. Five micrograms of RNA were first denatured 10 min at 70°C in the presence of 2 l of 100 M primer in a total volume of 26.5 l. First-strand synthesis was generated in a 40-l volume by adding 2 l of deoxynucleotide triphosphate (dNTP) at 10 mM, 1 l of RNase inhibitor, 1 l of 0.1 M DTT, 8 l of 5ϫ buffer (250 mM Tris-HCl, pH 8.3, 375 mM KCl, 15 mM MgCl 2 ), and 1.5 l of Superscript II TM (200 units/l, Invitrogen).…”

“…the fat body in insects) and in circulating fluids (blood or coelomic fluid) (6) are also found in the nervous system. Indeed, lectin family proteins (17) and the Rel family member Dif and the IB molecule Cactus, known as transcriptional regulators of several antimicrobial peptides, have been co-localized in the larval nervous systems of Drosophila mela-* This work was supported in part by the Centre National de la Recherche Scientifique, the Ministère de l'Education Nationale, de la Recherche et des Technologies, the Fond Economique du Développe-ment Européen et Régional, the Conseil Régional Nord-Pas-de-Calais, the Génopôle de Lille, the Plateau de Protéomique de l'Université des Sciences et Technologies de Lille, and the National Institutes of HealthFogarty Grant. The costs of publication of this article were defrayed in part by the payment of page charges.…”

Cholesterol-Responsive Metabolic Proteins Are Required for Larval Development in Caenorhabditis elegans

“…Lectins in other organisms such as in Drosophila have been reported to function during development (Seppo and Tiemeyer, 2000). Expression of lectins was increased by triggering innate immune system in Drosophila (Pace et al, 2002), and lectin level was also increased upon stress in human serum (Iwamoto et al, 2010). The levels of galectins may also increase in response to some stresses including CS in C. elegans.…”

Synthesis of Fluorescence-Labeled Gal.BETA.1-3Fuc and Gal.BETA.1-4Fuc as Probes for the Endogenous Glyco-Epitope Recognized by Galectins in Caenorhabditis elegans

“…4) It is known that a Galb1-4GlcNAc (N-acetyllactosamine) unit is the endogenous glyco-epitope recognized by vertebrate galectins. [5][6][7][8] Among galectins from invertebrate species including Caenorhabditis elegans, specificity for N-acetyllactosamine was reported, although the existence of the glycan containing N-acetyllactosamine units has not been confirmed in C. elegans. [9][10][11][12][13][14] This discrepancy raised a question concerning the endogenous glyco-epitope that is recognized by galectins in C. elegans.…”