Karageorgos L E, Isaac E L, Brooks D A, Ravenscroft E M, Davey R, Hopwood J J, Meikle P J
Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, South Australia.
Exp Cell Res. 1997 Jul 10;234(1):85-97. doi: 10.1006/excr.1997.3581.
Lysosomal biogenesis is an orchestration of the structural and functional elements of the lysosome to form an integrated organelle and involves the synthesis, targeting, functional residence, and turnover of the proteins that comprise the lysosome. We have investigated lysosomal biogenesis during the formation and dissipation of storage vacuoles in two model systems. One involves the formation of sucrosomes in normal skin fibroblasts and the other utilizes storage disorder-affected skin fibroblasts; both of these systems result in an increase in the size and the number of lysosomal vacuoles. Lysosomal proteins, beta-hexosaminidase, alpha-mannosidase, N-acetylgalactosamine-4-sulfatase, acid phosphatase, and the lysosome-associated membrane protein, LAMP-1, were shown to be elevated between 2- and 28-fold above normal during lysosomal storage. Levels of mRNA for the lysosome-associated membrane proteins LAMP-1 and LAMP-2, N-acetylgalactosamine-4-sulfatase, and the 46- and 300-kDa mannose-6-phosphate receptors were also elevated 2- to 8-fold. The up-regulation of protein and mRNA lagged 2-4 days behind the formation of lysosomal storage vacuoles. Correction of storage, in both systems, resulted in the rapid decline of the mRNA to basal levels, with a slower decrease in the levels of lysosomal proteins. Lysosomal biogenesis in storage disorders is shown to be a regulated process which is partially controlled at, or prior to, the level of mRNA. Although lysosomal proteins were differentially regulated, the coordination of these events in lysosomal biogenesis would suggest that a common mechanism(s) may be in operation.
溶酶体生物发生是溶酶体的结构和功能元件的一种编排，以形成一个整合的细胞器，并且涉及构成溶酶体的蛋白质的合成、靶向、功能驻留和周转。我们在两个模型系统中研究了储存液泡形成和消散过程中的溶酶体生物发生。一个涉及正常皮肤成纤维细胞中蔗糖体的形成，另一个利用受储存障碍影响的皮肤成纤维细胞；这两个系统都会导致溶酶体液泡的大小和数量增加。溶酶体蛋白、β-己糖胺酶、α-甘露糖苷酶、N-乙酰半乳糖胺-4-硫酸酯酶、酸性磷酸酶以及溶酶体相关膜蛋白LAMP-1，在溶酶体储存期间显示比正常水平升高2至28倍。溶酶体相关膜蛋白LAMP-1和LAMP-2、N-乙酰半乳糖胺-4-硫酸酯酶以及46 kDa和300 kDa甘露糖-6-磷酸受体的mRNA水平也升高了2至8倍。蛋白质和mRNA的上调比溶酶体储存液泡的形成滞后2至4天。在这两个系统中，储存的纠正导致mRNA迅速下降至基础水平，溶酶体蛋白水平下降较慢。储存障碍中的溶酶体生物发生显示是一个受调控的过程，在mRNA水平或之前受到部分控制。尽管溶酶体蛋白受到不同的调控，但溶酶体生物发生中这些事件的协调表明可能存在一种共同机制在起作用。
