Regulation of Glucose Transport in Quiescent, Lactating, and Neoplastic Mammary Epithelia
Abstract
We studied developmental changes in glucose transporter targeting in mammary gland, sought novel proteins affecting Glut1 targeting, and studied glucose transport in breast cancer cells. Most significant conclusions are: 1. In normal CIT3 mammary epithelial cells, GLUT1 colocalizes with Golgi markers b-COP and a-mannosidase but not with the trans-Golgi marker Bodipy TR-ceramide. 2. There are no higher molecular weight isoforms of GLUT1. 3. Glycosylation plays no role in GLUT 1 targeting to Golgi. 4. There is no evidence that lactogenic hormones stimulate expression of a novel glucose transporter. 5. Changes in Golgi markers with forced weaning suggest that changes in GLUT1 targeting during that time may reflect a dynamic reorganization process affecting all Golgi constituents. 6. GLUTl-EBFP fusion protein offers the opportunity to study transporter targeting in living cells. 7. Golgi GLUT1 purified under non-denaturing conditions has an apparent molecular weight of 130 kD, suggesting that it may be associated with a protein of 70-90 kD. 8. MDA23 1 cells exhibit very high rates of glucose transport but do not appear to utilize GLUT1 for this purpose, suggesting expression of a novel transporter or "oncotransporter."; these cells sequester GLUT1 in an atypical- appearing intracellular compartment whether or not prolactin and hydrocortisone are present.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1998
- Accession Number
- ADB253628
Entities
People
- F. S. Cole
Organizations
- Washington University in St. Louis