Revealing the anti-HRP epitope in Drosophila and Caenorhabditis

Abstract

Antibodies are very often used as specific cell and/or tissue markers. An example of this is anti-horseradish peroxidase (HRP), an antibody raised against a plant glycoprotein, which was shown some twenty-five years ago to specifically stain neural tissue in an animal, Drosophila melanogaster. This peculiar finding was later expanded to other invertebrate species including Caenorhabditis elegans, which were also shown to bear anti-HRP epitopes. Initial experiments indicated that the epitopes recognised by anti-HRP in invertebrates are of carbohydrate nature. Indeed, more recent experiments have characterised relevant core alpha1-3-fucosylated N-glycan structures that act as epitopes in various model and parasitic organisms. Moreover, a number of enzymes required for the synthesis of such structures have been identified. Over the years, medically-relevant roles of these structures have become apparent as regards allergenicity and immunoregulation. Although major advances have been made in understanding of the underlying mechanisms and structures related to the anti-HRP epitope, the in vivo role of the relevant epitopes in neural and other tissues is yet to be resolved. Current understanding of the anti-HRP epitopes synthesis and their relevance is discussed and elaborated.

Entomotoxic and nematotoxic lectins and protease inhibitors from fungal fruiting bodies

“…In the case of CCL2, however, a single, non-canonical binding site binds with high affinity to Gal-β1,4-(Fuc-α1,3)GlcNAc and to GlcNAc-β1, 4-(Fuc-α1,3)GlcNAc (Schubert et al 2012). The latter epitope is called the anti-HRP epitope, since it is found in the core of plant N-glycans, e.g., on the horseradish peroxidase and glycoproteins of many invertebrates, and is a known allergen (Paschinger et al 2009). …”

“…This toxicity is mediated by binding to the anti-HRP epitope in the core of nematode N-glycans (Schubert et al 2012). The absence of entomotoxicity may be due to spatial restriction of the anti-HRP epitope to the nervous system in insects (Paschinger et al 2009). The mechanism of toxicity of these (and other) hololectins is not clear.…”

N-glycosylation requirements in neuromuscular synaptogenesis

“…In the central brain mushroom body learning/memory center, Mgat1 nulls show fused lobes similar to fused lobes (fdl) mutants in β-Nacetylglucosaminidase, which removes the MGAT1-added GlcNAc (Léonard et al, 2006;Sarkar et al, 2006). MGAT1 is also required for α3 fucose addition, a neuron-specific modification routinely labeled with anti-horseradish peroxidase (HRP) (Desai et al, 1994;Paschinger et al, 2009). Overexpression of the fucose transferase generating HRP glycans increases peripheral sensory neuron clustering, ventral nerve cord growth and glial migration (Rendić et al, 2010).…”

The Drosophila Neurally Altered Carbohydrate Mutant Has a Defective Golgi GDP-fucose Transporter

“…nac mutants have reduced levels of a neural carbohydrate epitope that is produced by ␣1,3-linkage of a fucose residue to the N-glycan core (16 -18). Due to its identification as a dominant epitope in the plant glycoprotein horseradish peroxidase, this core ␣1,3-fucosylated N-glycan is also known as the horseradish peroxidase (HRP) epitope (19,20).…”