A CHINESE-HAMSTER OVARY CELL-LINE WITH A TEMPERATURE-CONDITIONAL DEFECT IN RECEPTOR RECYCLING IS PLEIOTROPICALLY DEFECTIVE IN LYSOSOME BIOGENESIS

We have previously described the isolation of a Chinese hamster ovary cell line, TfT1.11, that has a pleiotropic, temperature-conditional de fect in receptor recycling (Cain, C. C., Wilson, R. B., and Murphy, R. F. (1991) J. Biol. Chem. 266, 11746-11752). These cells show a rapid loss of cell surface receptors upon temperature shift due to a reducti on in the rate of receptor recycling. We show here that, in addition t o altered receptor recycling, TfT1.11 cells show three defects in lyso some biogenesis. At the nonpermissive temperature, they 1) redistribut e at least one lysosomal enzyme from lysosomes to endosomes, 2) fail t o transfer fluid-phase material from early endosomes to later compartm ents, and 3) fail to accumulate fluid-phase markers due to increased e fflux of internalized material. The results suggest that the processes of recycling from the endosome and movement of material from endosome s to lysosomes are tightly linked.