Impaired lysosomes in a temperature-sensitive mutant of Chinese hamster ovary cells.

Abstract

Abstract. We describe here the properties of a mutant of Chinese hamster ovary cells that expresses a conditional-lethal mutation affecting dense lysosomes. This mutant, termed V.24

Retention of secretory proteins in an intermediate compartment and disappearance of the Golgi complex in an END4 mutant of Chinese hamster ovary cells

“…Previous studies indicated that the properties of mutant V.24.1 are consistent with the presence of a single and revertible genetic lesion that creates a temperature-sensitive protein (8). We recently reported that secretion in V.24.1 cells was blocked at a step before the medial Golgi (39,56).…”

“…Progress in understanding secretion would also be advanced by isolating and analyzing secretion-defective mutants in animal cells. We previously isolated and studied a temperature-sensitive, conditionallethal mutant of CHO cells, termed V.24.1, that defined the End4 complementation group (7) and which had aberrant lysosomes at the restrictive temperature (8). Subsequent studies demonstrated that V.24.1 cells were defective in secretion (39,56).…”

Role of vacuolar acidification in protein sorting and zymogen activation: a genetic analysis of the yeast vacuolar proton-translocating ATPase.

“…Secondary antibody (alkaline phosphatase-conjugated goat anti-rabbit or goat anti-mouse antibody) was used and visualized by addition of 5-bromo-VOL. 10,1990 3740 YAMASHIRO ET AL.…”

“…The first approach utilizes weak bases, such as chloroquine and NH4Cl, which have been demonstrated to raise the intralysosomal pH of mammalian cells (44). Numerous (41,50,51,70) or lysosomal acidification (10). An aberrantly high level of lysosomal enzyme activity was detected in the extracellular medium during the growth of these mutants, suggesting that newly synthesized lysosomal protein was being mislocalized.…”

Sandy: a new mouse model for platelet storage pool deficiency

“…Proton pump activity was measured (Colbaugh et al 1989) by the initial rate of acridine orange accumulation within acidic vesicles. Accumulation was measured as the difference between the absorbance at 492 nm and 540 nm in an LKB 4054 Ultrospec Plus spectrophotometer.…”