A new approach for cellular injury

细胞外信号传导通常通过信号分子与细胞表面上的受体结合或通过内吞作用机制内化而转导至细胞。近年来，一些蛋白质被发现可以直接从细胞外空间渗透到细胞质和细胞核中，并在那里发挥作用。VP 22是一种能穿透细胞质和细胞核的单纯疱疹病毒I型蛋白。有趣的是，与VP 22的嵌合蛋白也被证明保留了这种能力。在本研究中，我们将VP 22和HSP 27（一种具有抗细胞应激能力的分子伴侣）嵌合，以探索一种新的药物传递系统。其中一个VP 22-HSP 27是一个不稳定的蛋白质，合成后立即降解，另一个VP 22-HSP 27更稳定，我们用免疫荧光和western blot检测了它的表达。表达该蛋白的细胞出乎意料地显示出对细胞应激敏感，这表明嵌合体VP 22-HSP 27对内源性HSP 27具有显性负性特征。进一步的努力，使嵌合蛋白与VP 22和HSP 27，或其他有用的蛋白质将被探索。

Extracellular signalling is usually transduced to cells through binding of signalling molecules to the receptors on the cell surface or internalization of them by endocytosis machinery. Recently some proteins have been found to penetrate directly from extracellular space to cytoplasm and nucleus, and function there. VP22, a herpes simplex virus I protein, is such a protein that can penetrate to cytoplasm and nucleus. Interestingly, a chimeric protein with VP22 was also demonstrated to preserve such an ability. In this study, we made chimeric proteins with VP22 and HSP27, a chaperone that has a cytoprotective ability against cellular stresses, to explore a new drug delivery system. One chimeric VP22-HSP27 was an unstable protein that is degraded immediately after synthesis, the other VP22-HSP27 was more stable and we have detected its expression by immunofluorescence and western blot. The cells expressing this protein , unexpectedly, revealed sensitive to cellular stresses, which suggested the chimeric VP22-HSP27 had a dominant-negative character against endogenous HSP27. Further efforts making chimeric proteins with VP22 and HSP27, or other useful proteins will be explored.