title: Compartmental distribution of beta-hexosaminidase isoenzymes in I-cell fibroblasts.
abstract: A characteristic of the human lysosomal disorder I-cell disease is an abnormal excretion of most lysosomal hydrolases, including beta-N-acetyl-D-glucosaminidase (EC 3.2.1.30; beta-hexosaminidase) by cultured skin fibroblasts. Treatment of I-cell cultures with cycloheximide or tunicamycin demonstrated that (1) I-cell fibroblasts rapidly excrete all newly synthesized beta-hexosaminidase, (2) two qualitatively distinct pools of beta-hexosaminidase isoenzymes exist inside I-cell fibroblasts, one of which is a rapid-turnover excretory pool, and (3) the induction of an abnormal glycosylation of beta-hexosaminidase by tunicamycin in normal or I-cell fibroblast cultures does not affect subsequent excretion of the enzyme.
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism*; D002451:Cell Compartmentation; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D004588:Electrophoresis, Cellulose Acetate; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology*; D006596:Hexosaminidases / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D009081:Mucolipidoses / Q000201:enzymology*; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D007527:Isoenzymes; D014415:Tunicamycin; D003513:Cycloheximide; D006596:Hexosaminidases; D000118:Acetylglucosaminidase