Glycosyltransferases as Immunoglobulin Receptors
{'Code': '08070600', 'Directorate': {'LongName': 'Direct For Biological Sciences'}, 'Division': {'LongName': 'Div Of Molecular and Cellular Bioscience'}}
{'SignBlockName': 'Maryanna P. Henkart'}
Recent data from this laboratory suggests that an IgA receptor,                 secretory component (SC) is a galactosyltransferase (GT).  In the               presence of UDPgalactose, the enzyme transfers galactose to IgA.                In the absence of the sugar donor, however, the enzyme merely                   binds to the IgA.  The goal of this research is to determine                    whether secretory component is a galactosyltrasnferase by cloning               and sequencing the gene that encodes the IgA-specific galactosyl-               transferase.  To isolate the gene, antibodies will be used to                   identify bacteria transfected with GT cDNA.  In addition, a                     novel, functional screen will be employed.  This screen is based                on four, linked enzymes that produce insoluble formazan                         precipitates over cells that catalyze the transfer of galactose                 to a particular acceptor--in this case, IgA.  A functional screen               is critical because immunological probes might not discriminate                 among structurally related transferases, or transferase fragments               with shared epitopes and similar molecular weights.                                                                                                             Recent, preliminary biochemical, immunological, and functional                  evidence suggests that a natually occurring, antibody binding                   protein, secretory component (which is, itself, a primitive                     member of the immunoglobulin superfamily of proteins) may be an                 enzyme that not only recognizes and binds to the antibody (IgA)                 with which it associates, but also attaches sugar molecules to                  the IgA.  If the critical test proposed here demonstrates clearly               that secretory component is, indeed, a sugar transfering enzyme,                this would be the first clear case in which an extracellular                    receptor recognizes its ligand and modifies it chemically by the                addition of sugars.  The demonstration of this process would                    imply a new mechanism by which receptor-ligand interactions are                 established and modified and would have important implications                  for our understanding of how signals are transmitted between                    cells.
{'FirstName': 'Stephen', 'LastName': 'Roth', 'EmailAddress': None, 'StartDate': '07/15/1989', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of Pennsylvania', 'CityName': 'Philadelphia', 'ZipCode': '191046205', 'PhoneNumber': '2158987293', 'StreetAddress': 'Research Services', 'CountryName': 'United States', 'StateName': 'Pennsylvania', 'StateCode': 'PA'}
{'Code': '1136', 'Text': 'SIGNAL TRANSDCTN/CELL REGULATN'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8817883.xml'}