Kim Soo-A, Chang Sunghoe, Yoon Jung-Hoon, Ahn Sang-Gun
Department of Biochemistry, Dongguk University College of Oriental Medicine, Gyeongju, South Korea.
FEBS Lett. 2008 Mar 5;582(5):734-40. doi: 10.1016/j.febslet.2008.01.053. Epub 2008 Feb 5.
Heat shock protein 40 (Hsp40) functions as a co-chaperone of mammalian Heat shock protein 70 (Hsp70) and facilitates the ATPase activity of Hsp70, and also promotes the cellular protein folding and renaturation of misfolded proteins. In an effort to assess the effects of Hsp40, we generated TAT-fused Hsp40 (TAT-Hsp40). The cells were transduced with TAT-Hsp40 and exposed to H(2)O(2). We demonstrated that the TAT-Hsp40-transduced cells were more resistant to cellular cytotoxicity and cell death. In particular, the degradation of Hsp70 was significantly reduced in TAT-Hsp40-containing cells as a consequence of reduced ubiquitin-proteasome activity after oxidative injury. These data support the notion that Hsp40 may confer resistance to oxidative stress via the prevention of proteasome activity.
热休克蛋白40（Hsp40）作为哺乳动物热休克蛋白70（Hsp70）的共伴侣蛋白，促进Hsp70的ATP酶活性，还能促进细胞内蛋白质折叠以及错误折叠蛋白的复性。为了评估Hsp40的作用，我们构建了TAT融合的Hsp40（TAT-Hsp40）。用TAT-Hsp40转导细胞，然后使其暴露于H₂O₂。我们证明，转导了TAT-Hsp40的细胞对细胞毒性和细胞死亡更具抗性。特别是，由于氧化损伤后泛素-蛋白酶体活性降低，含TAT-Hsp40的细胞中Hsp70的降解显著减少。这些数据支持了Hsp40可能通过预防蛋白酶体活性来赋予细胞对氧化应激的抗性这一观点。
