Hspa8 dissociates from Lamp2

Intracellular proteins are targeted for proteolytic degradation in lysosome with the aid of chaperones. Heat shock cognate 71 kDa protein (Hspa8) transports substrates from the cytosol to the lysosomal membrane where it binds to Lysosome-associated membrane glycoprotein 2 (Lamp2). Subsequently, Lamp2 forms a multimeric complex and transfers the substrate into the lumen. The stability of this complex is regulated by the dynamics of Hspa8. Cytosolic Hspa8 binds with Lamp2 multimers in the lysosomal membrane and trigger their disassembly into monomeric units (Bandyopadhyay U et al. 2008). Hspa8 dissociates from Lamp2 to make it available for further substrate autophagy.

细胞内蛋白质在溶酶体的帮助下，借助伴侣蛋白进行蛋白水解降解。热休克同源蛋白71 kDa（Hspa8）将底物从细胞质转运至溶酶体膜，并与溶酶体相关膜糖蛋白2（Lamp2）结合。随后，Lamp2形成多聚复合物，并将底物转移至腔内。该复合物的稳定性受Hspa8动态变化所调控。细胞质中的Hspa8与溶酶体膜上的Lamp2多聚体结合，触发其解聚成单体单位（Bandyopadhyay U 等人，2008年）。Hspa8与Lamp2解离，使其可供进一步的底物自噬利用。