Di-N-Acetyl Chitobiase (CTBS)

Chitobiase is a lysosomal glycosidase involved in degradation of asparagine-linked oligosaccharides on glycoproteins. There was a fused in-frame sequence that represented exons 2 and 3 from the gene for the G protein gamma-5 subunit (GNG5). Exons 2 and 3, respectively, code for the carboxyl-end of the gamma-5 protein and the 3-prime untranslated portion of its mRNA. This hybrid message had also been identified in human liver and retina by RT-PCR analysis. It was not known whether a hybrid protein was produced in vivo. Ahmad et al. (1995) demonstrated that both the CTB and the GNG5 genes map to 1p by PCR analysis of somatic cell hybrids; by fluorescence in situ hybridization using a YAC clone which contained both genes, they refined the localization to 1p22.