The ultimate goal of this project is to understand the oligomeric structure and structure-function relationships of the human hepatic asialoglycoprotein receptor (ASGP-R). This receptor serves as a convenient model to define general principles of receptor biosynthesis, subunit assembly, targeting, ligand binding, receptor-mediated endocytosis, and receptor cycling at the molecular level. In addition, because of its tissue and ligand specificity, the ASGP-R has the potential to be being the target and entry point for specific therapeutic agents directed to the liver. since genes can be specifically targeted to liver cells by coupling them to the ASGP-R ligand, this receptor also affords the potential for organ-specific gene therapy.
The aims of this proposal are threefold. First, we will determine the oligomeric structure and stoichiometry of the H1 and H2 subunits of the ASGP-R, using chemical cross-linkers and affinity isolation techniques. Second, we aim to define and analyze the domains of H1 and H2 that complement function defects in the other subunit. We will do this by constructing deletion mutants and chimeras of H1 and H2, expressing them alone or together with intact subunits in NIH 3T3 fibroblasts, and testing for receptor function. Finally, we will characterize the effects of ligand occupancy on receptor internalization and trafficking, seeking in particular to elucidate the biochemical and biophysical mechanisms by which ligand occupancy """"""""triggers"""""""" an acceleration in the internalization rate of receptor-ligand complexes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK045047-03
Application #
2144300
Study Section
Physiological Chemistry Study Section (PC)
Project Start
1993-02-01
Project End
1997-01-31
Budget Start
1995-02-01
Budget End
1996-01-31
Support Year
3
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Boston University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118