Charette Steve J, Cosson Pierre
Université de Genève, Centre Médical Universitaire, Département de Physiologie Cellulaire et Métabolisme, 1 rue Michel Servet, CH-1211 Geneva 4, Switzerland.
J Cell Sci. 2007 Jul 15;120(Pt 14):2338-43. doi: 10.1242/jcs.009001.
Chediak-Higashi syndrome (CHS) is characterized at the cellular level by a defect in the ability of cells to secrete lysosomes. However, the precise step affected in the secretion process is unclear. We characterized Dictyostelium discoideum cells containing a mutation in lvsB, the homolog of the human gene (LYST) involved in CHS. As observed in mammalian cells, secretion of lysosome-derived compartments was affected in lvsB mutant cells. This defect was mirrored by a decrease in the number of fusion-competent post-lysosomal compartments, which in Dictyostelium can be clearly distinguished from lysosomes. In addition, the transfer of endocytosed particles from lysosomes to post lysosomes was strongly diminished in lvsB mutant cells compared with the wild type. These results suggest that LvsB is primarily involved in transport from lysosomes to post lysosomes, and thus plays a critical role in the maturation of lysosomes into fusion-competent post-lysosomal compartments.
切-东综合征（CHS）在细胞水平上的特征是细胞分泌溶酶体的能力存在缺陷。然而，分泌过程中受影响的确切步骤尚不清楚。我们对含有lvsB基因突变的盘基网柄菌细胞进行了表征，lvsB基因是参与CHS的人类基因（LYST）的同源基因。正如在哺乳动物细胞中观察到的那样，lvsB突变细胞中溶酶体来源区室的分泌受到影响。这种缺陷反映在具有融合能力的溶酶体后区室数量的减少上，在盘基网柄菌中，这些区室可以与溶酶体明显区分开来。此外，与野生型相比，lvsB突变细胞中内吞颗粒从溶酶体到溶酶体后的转移显著减少。这些结果表明，LvsB主要参与从溶酶体到溶酶体后的运输，因此在溶酶体成熟为具有融合能力的溶酶体后区室中起着关键作用。
