High impact information on Hexo1

• Glycan profiles change during normal development consistent with increasing alpha-mannosidase II and core fucosyl-transferase enzyme activities, and with decreasing activity of the Fused lobes processing hexosaminidase [1].
• Therefore, we conclude that the fdl gene encodes a novel hexosaminidase responsible for the occurrence of paucimannosidic N-glycans in Drosophila [2].
• Most processed, e.g. fucosylated, N-glycans on insect glycoproteins terminate in mannose, yet the relevant modifying enzymes require the prior action of N-acetylglucosaminyltransferase I. This led to the hypothesis that a hexosaminidase acts during the course of N-glycan maturation [2].
• When expressed in Pichia pastoris, the enzyme exhibited a substrate specificity similar to that previously described for a hexosaminidase activity from Sf-9 cells, i.e. it hydrolyzed exclusively the GlcNAc residue attached to the alpha1,3-linked mannose of the core pentasaccharide of N-glycans [2].
• HEX 1 and HEX 2 are similar to mammalian isoenzyme A and isoenzyme B, respectively.These findings represent the first report on the characterization of sperm proteins that are potentially involved in interactions with the egg in Insects [3].

Anatomical context of Hexo1

• Although none of the genes was testis-specific, fdl was highly and preferentially expressed in the testis, whereas Hexo1 and Hexo2 showed broader tissue expression [4].

Analytical, diagnostic and therapeutic context of Hexo1

• SDS-PAGE showed that HEX 1 and HEX 2 are dimers formed by subunits with different molecular sizes, whereas alpha-mannosidase consists of three subunits with different molecular weights [3].

References