Strømhaug P E, Seglen P O
Department of Tissue Culture, Norwegian Radium Hospital, Oslo.
Biochem J. 1993 Apr 1;291 ( Pt 1)(Pt 1):115-21. doi: 10.1042/bj2910115.
[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.
电注入分离的大鼠肝细胞中的[14C]乳糖通常会被自噬吞噬,转移到溶酶体并由溶酶体β-半乳糖苷酶降解,但在高浓度天冬酰胺存在时,这种转移会受到抑制,乳糖会在溶酶体前自噬/内吞液泡(双膜体)中积累。添加酵母β-半乳糖苷酶可防止这种积累,该酶通过内吞作用转移到含乳糖的液泡中。丙胺是一种能够中和酸性液泡的弱碱,可保护自噬吞噬的乳糖免受内源性和外源性β-半乳糖苷酶的作用,这表明双膜体与溶酶体一样,具有酸性内部环境。