Van Dyke R W, Root K V, Schreiber J H, Wilson J M
Department of Medicine, University of Michigan, Ann Arbor.
Biochem Biophys Res Commun. 1992 Apr 15;184(1):300-5. doi: 10.1016/0006-291x(92)91192-s.
The role of CFTR in lysosome acidification was examined in CFPAC-1 pancreatic adenocarcinoma cells with the delta F508 mutation that were transduced with a retroviral vector (PLJ-CFPAC) or with the normal CFTR gene (CFTR-CFPAC). Steady-state lysosomal pHi in intact cells was lower in PLJ-CFPAC cells than CFTR-CFPAC cells (3.55 vs 3.80) and was not affected by cAMP or forskolin. Initial rates of ATP-dependent acidification of isolated lysosomes and steady-state ATP-dependent pHi were similar in both cell lines over a range of chloride concentrations and were not altered when cells were exposed to cAMP or to forskolin prior to preparation of lysosomes. These observations suggest that CFTR plays no role in acidification of lysosomes, possibly due to limited permeability of lysosomal membranes to chloride.
在携带ΔF508突变的CFPAC-1胰腺腺癌细胞中，利用逆转录病毒载体（PLJ-CFPAC）或正常CFTR基因（CFTR-CFPAC）转导来研究CFTR在溶酶体酸化中的作用。完整细胞中，PLJ-CFPAC细胞的稳态溶酶体pH值低于CFTR-CFPAC细胞（3.55对3.80），且不受cAMP或福司可林影响。在一系列氯离子浓度范围内，两种细胞系中分离的溶酶体的ATP依赖性酸化初始速率和稳态ATP依赖性pH值相似，并且在制备溶酶体之前，当细胞暴露于cAMP或福司可林中时，这些参数没有改变。这些观察结果表明，CFTR在溶酶体酸化中不起作用，这可能是由于溶酶体膜对氯离子的通透性有限。
