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. 1993 Apr 1;291(Pt 1):115–121. doi: 10.1042/bj2910115

Evidence for acidity of prelysosomal autophagic/endocytic vacuoles (amphisomes).

P E Strømhaug 1, P O Seglen 1
PMCID: PMC1132489  PMID: 8471030

Abstract

[14C]Lactose electroinjected into isolated rat hepatocytes is normally autophagocytosed, transferred to lysosomes and degraded by lysosomal beta-galactosidase, but at high concentrations of asparagine the transfer is inhibited and lactose accumulates in prelysosomal autophagic/endocytic vacuoles (amphisomes). The accumulation can be prevented by addition of yeast beta-galactosidase, which is transferred to the lactose-containing vacuoles by endocytosis. Propylamine, a weak base capable of neutralizing acidic vacuoles, protects autophagocytosed lactose against both endogenous and exogenous beta-galactosidase, suggesting that amphisomes, like lysosomes, have an acidic internal environment.

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Selected References

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