In their role as molecular chaperones, heat shock proteins (Hsps) mediate protein folding thereby mitigating cellular damage caused by physiological and environmental stress. Nauplii of the crustacean Artemia franciscana respond to heat shock by producing Hsps; however, the effects of cold shock on Hsp levels in A. franciscana have not been investigated previously. The effect of cold shock at 1 °C followed by recovery at 27 °C on the amounts of ArHsp90, Hsp70, ArHsp40, and ArHsp40-2 mRNA and their respective proteins in A. franciscana nauplii was examined by quantitative PCR (qPCR) and immunoprobing of western blots. The same Hsp mRNAs and proteins were also quantified during incubation of nauplii at their optimal growth temperature of 27 °C. qPCR analyses indicated that the abundance of ArHsp90, Hsp70, and ArHsp40 mRNA remained relatively constant during both cold shock and recovery and was not significantly different compared with levels at optimal temperature. Western blotting revealed that ArHsp90, ArHsp40, and ArHsp40-2 were generally below baseline, but at detectable levels during the 6 h of cold shock, and persisted in early recovery stages before declining. Hsp70 was the only protein that remained constant in quantity throughout cold shock and recovery. By contrast, all Hsps declined rapidly during 6 h when nauplii were incubated continuously at 27 °C optimal temperature. Generally, the amounts of ArHsp90, ArHsp40, and ArHsp40-2 were higher during cold shock/recovery than those during continuous incubation at 27 °C. Our data support the conclusion that low temperature preserves Hsp levels, making them available to assist in protein repair and recovery after cold shock.

热休克蛋白 (Hsps) 作为分子伴侣，介导蛋白质折叠，从而减轻生理和环境应激引起的细胞损伤。甲壳类动物卤虫的无节幼体通过产生热休克蛋白来应对热休克；然而，冷休克对A. franciscana中热休克蛋白水平的影响之前尚未被研究过。通过定量 PCR (qPCR) 和免疫探针检测 1 °C 冷激和 27 °C 恢复对A. franciscana无节幼体中ArHsp90 、 Hsp70 、 ArHsp40和ArHsp40-2 mRNA 及其各自蛋白质含量的影响蛋白质印迹。在无节幼体最佳生长温度 27 °C 的培养过程中，也对相同的Hsp mRNA 和蛋白质进行了定量。 qPCR 分析表明， ArHsp90 、 Hsp70和ArHsp40 mRNA 的丰度在冷激和恢复过程中保持相对恒定，与最佳温度下的水平相比没有显着差异。蛋白质印迹显示 ArHsp90、ArHsp40 和 ArHsp40-2 总体低于基线，但在冷休克 6 小时内处于可检测水平，并且在下降之前在早期恢复阶段持续存在。 Hsp70 是唯一在冷休克和恢复过程中数量保持恒定的蛋白质。相比之下，当无节幼体在 27 °C 最佳温度下连续培养时，所有 Hsp 在 6 小时内迅速下降。一般来说，冷休克/恢复期间 ArHsp90、ArHsp40 和 ArHsp40-2 的含量高于 27 °C 连续孵育期间的含量。 我们的数据支持这样的结论：低温可以保持热休克蛋白水平，使其有助于冷休克后的蛋白质修复和恢复。