/sup 3/H)forskolin. Direct photoaffinity labeling of the erythrocyte D-glucose transporter
Irradiation of erythrocyte ghosts in the presence of (/sup 3/H)forskolin resulted in a concentration-dependent, covalent incorporation of radiolabel into several of the major membrane protein bands. Most of the incorporation occurred in four regions of the gel. Peak 1 (216 kDa) was a sharp peak near the top of the gel in the region corresponding to spectrin. Peak 2 appeared to be associated with band 3 (89 kDa), while a third peak occurred around the position of band 4.2 (76 kDa). The fourth region of labeling was a broad area between 43-75 kDa which corresponds to the region of the glucose transporter. Forskolin labeling of this region was inhibited by cytochalasin B and D-glucose, but not L-glucose. Extraction of extrinsic membrane proteins resulted in a loss of radiolabeled protein from the 216- and 76-kDa regions. Treatment of membranes labeled with either cytochalasin B or forskolin with endo-beta-galactosidase resulted in identical shifts of the 43 to 75-kDa peaks to 42 kDa. Similarly, trypsinization of membranes photolabeled with either cytochalasin B or forskolin resulted in the generation of a 17-kDa radiolabeled fragment in both cases. Photoincorporation of (/sup 3/H)cytochalasin B into the glucose transporter was blocked in a concentration-dependent manner by unlabeled forskolin.
- Research Organization:
- Southern Illinois Univ. School of Medicine, Carbondale
- OSTI ID:
- 6498762
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 13
- Country of Publication:
- United States
- Language:
- English
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GLUCOSE
MEMBRANE TRANSPORT
PROTEINS
LABELLING
CELL MEMBRANES
DOSE-RESPONSE RELATIONSHIPS
ERYTHROCYTES
IRRADIATION
MOLECULAR WEIGHT
PHOTOCHEMISTRY
TRITIUM COMPOUNDS
ALDEHYDES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
CELL CONSTITUENTS
CHEMISTRY
HEXOSES
LABELLED COMPOUNDS
MATERIALS
MEMBRANES
MONOSACCHARIDES
ORGANIC COMPOUNDS
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560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture