Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools
The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of microsomal membranes, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses, which may be interpreted as indicating the presence of a radiation-sensitive inhibitor. These results suggest that the adipocyte glucose transporter occurs as a monomer in the plasma membrane while existing in the intracellular reserve pool either as a homodimer or as a stoichiometric complex with a protein of an approximately equal size.
- Research Organization:
- State Univ. of New York, Buffalo
- OSTI ID:
- 6323128
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 262:17
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of insulin and glucocorticoids on glucose transporters in rat adipocytes
The regulation of glucose transport in the heart of control and diabetic rats: With special emphasis on the glucose transporter
Related Subjects
FAT CELLS
BIOLOGICAL RADIATION EFFECTS
RADIOSENSITIVITY
GLUCOSE
MEMBRANE TRANSPORT
PROTEINS
BIOCHEMICAL REACTION KINETICS
RECEPTORS
ADIPOSE TISSUE
CELL MEMBRANES
DOSE-RESPONSE RELATIONSHIPS
INSULIN
MICROSOMES
RATS
ALDEHYDES
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BIOLOGICAL EFFECTS
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CONNECTIVE TISSUE
CONNECTIVE TISSUE CELLS
HEXOSES
HORMONES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANOIDS
PEPTIDE HORMONES
RADIATION EFFECTS
REACTION KINETICS
RODENTS
SACCHARIDES
SOMATIC CELLS
TISSUES
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture