Aufricht C, Lu E, Thulin G, Kashgarian M, Siegel N J, Van Why S K
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8064, USA.
Am J Physiol. 1998 Feb;274(2):F268-74. doi: 10.1152/ajprenal.1998.274.2.F268.
The pattern of 72-kDa heat-shock protein (HSP-72) induction after renal ischemia suggests a role in restoring cell structure. HSP-72 activity in the repair and release from denatured and aggregated proteins requires ATP. Protein aggregates were purified from normal and ischemic rat renal cortex. The addition of ATP to cortical homogenates reduced HSP-72, Na(+)-K(+)-ATPase, and actin in aggregates subsequently isolated, suggesting that their interaction is ATP dependent. Altering ATP hydrolysis in the purified aggregates, however, had different effects. ATP released HSP-72 during reflow and preserved Na(+)-K(+)-ATPase association with aggregates at 2 h but had no effect in controls or at 6 h reflow and caused no change in actin. These results indicate that HSP-72 complexes with aggregated cellular proteins in an ATP-dependent manner and suggests that enhancing HSP-72 function after ischemic renal injury assists refolding and stabilization of Na(+)-K(+)-ATPase or aggregated elements of the cytoskeleton, allowing reassembly into a more organized state.
肾脏缺血后72-kDa热休克蛋白（HSP-72）的诱导模式表明其在恢复细胞结构中发挥作用。HSP-72从变性和聚集蛋白中修复及释放的活性需要ATP。从正常和缺血大鼠肾皮质中纯化蛋白聚集体。向皮质匀浆中添加ATP可减少随后分离出的聚集体中的HSP-72、钠钾ATP酶和肌动蛋白，这表明它们的相互作用依赖于ATP。然而，改变纯化聚集体中的ATP水解会产生不同的影响。ATP在再灌注期间释放HSP-72，并在2小时时保持钠钾ATP酶与聚集体的结合，但在对照组或再灌注6小时时没有影响，且对肌动蛋白没有改变。这些结果表明，HSP-72以ATP依赖的方式与聚集的细胞蛋白形成复合物，并表明在缺血性肾损伤后增强HSP-72功能有助于钠钾ATP酶或细胞骨架聚集成分的重新折叠和稳定，使其重新组装成更有序的状态。
