The long term objective of this research is to understand the regulation, at the genetic and molecular level, of the specific subcellular localization of Beta-glucuronidase. Glucuronidase is an unusual acid hydrolase in that it has a dual subcellular location in several mammalian tissues with up to 40% of total cellular glucuronidase present as a complex with the protein egasyn in liver microsomes. The results will contribute to knowledge about the mechanisms of biosynthesis of specific subcellular organelles such as the lysosome; an organelle thought to be involved in disease processes such as tumor cell killing and chronic inflammation, and to knowledge of disease processes involving enzyme mislocalization. The systems to be utilized include inbred mouse strains, congenic mutant and wild mice with alterations in glucuronidase subcellular distribution or in glucuronidase processing. These mutants enable studies difficult to perform by purely biochemical or molecular techniques. Also specific antibodies to glucuronidase and egasyn will be utilized to study turnover, processing and subcellular localization of the glucuronidase-egasyn complex.
The specific aims are: (1) to kinetically analyze the turnover of the glucuronidase-egasyn complex; (2) to define the structural features of glucuronidase and egasyn important in the formation and stabilization of the glucuronidase-egasyn complex; (3) to examine a novel regulation by egasyn of the post translational processing of lysosomal glucuronidase; (4) to examine the genetic regulation of the structure and stability of the glucuronidase-egasyn complex in various inbred strains, congenic mutant and wild mice; (5) to examine proteins, other than glucuronidase, complexed with egasyn. Also to determine whether these proteins are altered in the Eg(o/o) mutant both in regard to physical properties and subcellular location; (6) to identify the subcellular and suborganellar location(s) of the glucuronidase-egasyn complex.
Showing the most recent 10 out of 15 publications
