Abstract

The aim of this project is to define at the molecular level the mechanism by which trophic glycoprotein hormones (thyrotropin) elicit biological effects in their target (thyroid) cells with cholera toxin as a model system. The proposed research will focus on the study of: (i) the nature and structure of the binding sites on the B protomer of cholera toxin for its receptor the monosialoganglioside GM1; (ii) conformational changes imposed on cholera toxin and thyrotropin upon receptor interaction and (iii) mechanism of insertion and translocation into the plasma membrane. Mutual perturbations of ligand (cholera toxin, thyrotropin) and plasma membrane will be studied by spectroscopic techniques such as steady state and time resolved fluorescence spectroscopy. The potential involvement of membrane bound enzymes, NAD glycohydrolase and ADP ribosyltransferase with catalytic activities analogous to the A protomer of cholera toxin, in the intermediate phase of transmembrane signalling will be studied in the thyroid. Thyroid plasma membranes will be derived from bovine thyroid, functional (FRTL) and non functional (FRT) rat thyroid cells in culture.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases (NIADDK)
Type
Research Project (R01)
Project #
5R01AM032136-03
Application #
3152431
Study Section
Endocrinology Study Section (END)
Project Start
1983-07-01
Project End
1986-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
3
Fiscal Year
1985
Total Cost
Indirect Cost

  Institution

Name
Antwerp State University Centre
Department
Type
DUNS #
City
Antwerp
State
Country
Belgium
Zip Code

  Publications

De Wolf, M J; Van Dessel, G A; Lagrou, A R et al. (1987) pH-induced transitions in cholera toxin conformation: a fluorescence study. Biochemistry 26:3799-806
van Dessel, G; de Wolf, M; Lagrou, A et al. (1986) On the binding of dolichol by bovine liver supernatant. Biochim Biophys Acta 878:338-45
van Dessel, G; de Wolf, M; Lagrou, A et al. (1986) On the binding of dolichol by human serum. Biochim Biophys Acta 878:346-52
De Wolf, M J; Van Dessel, G A; Lagrou, A R et al. (1985) Topography, purification and characterization of thyroidal NAD+ glycohydrolase. Biochem J 226:415-27
De Wolf, M; Van Dessel, G; Lagrou, A et al. (1985) Structural features of the binding site of cholera toxin inferred from fluorescence measurements. Biochim Biophys Acta 832:165-74
Depauw, H; de Wolf, M; van Dessel, G et al. (1985) Fluidity characteristics of bovine thyroid plasma membranes. Biochim Biophys Acta 814:57-67