Disease relevance of GNBP1

• The sensing of Gram-positive bacteria is mediated by the pattern recognition receptors PGRP-SA and GNBP1 that cooperate to detect the presence of infections in the host [1].
• In vivo RNA interference analysis reveals an unexpected role for GNBP1 in the defense against Gram-positive bacterial infection in Drosophila adults [2].
• These results suggest that DGNBP-1 functions as a pattern recognition receptor for LPS from Gram-negative bacteria and beta-1, 3-glucan from fungi and plays an important role in non-self recognition and the subsequent immune signal transmission for the induction of antimicrobial peptide genes in the Drosophila innate immune system [3].

High impact information on GNBP1

• These data indicate that PGRP-SD can function as a receptor for Gram-positive bacteria and shows partial redundancy with the PGRP-SA-GNBP1 complex [4].
• Northern blot analysis showed that GNBP was constitutively expressed in fat body, as well as in cuticular epithelial cells of naive silkworms [5].
• Comparison of the deduced amino acid sequence with known sequences revealed that GNBP contained a region displaying significant homology to the putative catalytic region of a group of bacterial beta-1,3 glucanases and beta-1,3-1,4 glucanases [5].
• The cDNA encoding this Gram(-) bacteria-binding protein (GNBP) was isolated from an immunized silkworm fat body cDNA library and sequenced [5].
• An mRNA that hybridized with GNBP cDNA was also found in the l(2)mbn immunocompetent Drosophila cell line [5].

Biological context of GNBP1

• In drosophila, detection of Gram-positive bacteria is mediated by cooperation between the peptidoglycan-recognition protein-SA (PGRP-SA) and Gram-negative binding protein 1 (GNBP1) proteins [4].
• We suggest a model whereby GNBP1 is involved in the hydrolysis of Gram-positive peptidoglycan producing new glycan reducing ends, which are subsequently detected by PGRP-SA [6].

Anatomical context of GNBP1

• High hydrostatic pressure (HHP)-mediated solubilization and refolding of five inclusion bodies (IBs) produced from bacteria, three gram-negative binding proteins (GNBP1, GNBP2, and GNBP3) from Drosophila, and two phosphatases from human were investigated in combination of a redox-shuffling agent (2 mM DTT and 6 mM GSSG) and various additives [7].

Associations of GNBP1 with chemical compounds

• DGNBP-1 has a high affinity to microbial immune elicitors such as lipopolysaccharide (LPS) and beta-1,3-glucan whereas no binding affinity is detected with peptidoglycan, beta-1,4-glucan, or chitin [3].

Other interactions of GNBP1

• Our results demonstrate that GNBP1 and PGRP-SA can jointly activate the Toll pathway [8].
• Sensing of Gram-positive bacteria in Drosophila: GNBP1 is needed to process and present peptidoglycan to PGRP-SA [9].
• Here, we report the identification of five novel SPs that function in an extracellular pathway linking the recognition proteins GNBP1 and PGRP-SA to Spz [10].

Analytical, diagnostic and therapeutic context of GNBP1

• Western blot, flow cytometric, and confocal laser microscopic analyses demonstrate that DGNBP-1 exists in both a soluble and a glycosylphosphatidylinositol-anchored membrane form in culture medium supernatant and on Drosophila immunocompetent cells, respectively [3].
• Purification and molecular cloning of an inducible gram-negative bacteria-binding protein from the silkworm, Bombyx mori [5].

References