Stable variant of LM fibroblast defective in fluid-phase but competent in receptor-mediated endocytosis
✍ Scribed by Hugues J.-P. Ryser; Wande Li; Richard Mandel; Wei-Chiang Shen
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 844 KB
- Volume
- 137
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
✦ Synopsis
The F-40 cell line, a stable variant of LM fibroblasts selected for its resistance to polyethylene glycol (PEG)-induced fusion (Roos and Davidson: Somatic Cell and Molecular Genetics 6:381-391, 1980), has a decreased capacity to internalize fluid-phase markers and nonspecifically surface-bound macromolecules. It is not defective in exocytosis since, after a short sucrose pulse, it release5 the same fraction of ingested sucrose into the medium as does the parental line. F40 cells have a normal capacity to carry out receptor-mediated endocytosis, as tested with "51-alpha-2 macroglobulin (alpha-2 MG) and '251-transferrin (Tf), and to recycle Tf receptor to the cell surface. These data demonstrate that receptor-mediated and non-receptor mediated endocytosis are distinct processes that can be altered independently. Of the many membrane fusions occurring in the course of endocytosis, the only one that appears associated with the defect in cell fusion characteristic of F40 cells is the formation of primary endocytotic vesicles engaged in non-receptor-mediated internalizations.