Reduced pinosome formation in a cell-fusion-impaired mutant of mouse lymphocytic cell line L5178Y.
Accumulation and release of a fluid-phase marker ([14C]-sucrose) were studied in a subline of the mouse lymphocytic cell line L5178Y and in a polyethylene glycol-resistant, intercellular-fusion-impaired mutant of this line. The mutant was found to accumulate [14C]-sucrose at a significantly slower rate than the parent. Analysis of release of preloaded label shows that the reduced rate of accumulation is due to a correspondingly low level of internalization, i.e., pinosome formation, rather than to a reduction in delivery of label to lysosomes. Cell-to-cell fusion and pinosome formation both involve a fusion event initiated at the extracellular surface of the plasma membrane, and we propose that the coordinate reduction in both processes suggests that they are mechanistically related.
D000818:Animals; D001692:Biological Transport; D002451:Cell Compartmentation; D002459:Cell Fusion; D002460:Cell Line; D007940:Leukemia L5178 / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D007942:Leukemia, Experimental / Q000503:physiopathology*; D008247:Lysosomes / Q000502:physiology; D051379:Mice; D009154:Mutation; D010873:Pinocytosis; D013395:Sucrose / Q000378:metabolism
D013395:Sucrose