Sola Biosciences, Inc., 27 Strathmore Road, Natick, MA, 01760, USA.
Sci Rep. 2017 Aug 17;7(1):8531. doi: 10.1038/s41598-017-09067-7.
For secreted proteins, proper protein folding is essential not only for biological function but also for secretion itself. Proteins with folding problems are trapped in the endoplasmic reticulum (ER) and are eventually degraded in the cytoplasm. In this study, we exploited co-expression of an artificial fusion protein, based on the sequence of a DnaJ protein, which could interact as co-chaperones in the Hsp70-based protein-folding system, with target recombinant secreted proteins to enhance their production and secretion. The J-domain sequence or a fragment thereof was conjugated to a target protein-binding domain that was capable of binding to a portion of the target-protein sequence. Production of many of the target proteins was significantly upregulated when co-expressed with the J-domain fusion protein. Surprisingly, the enhancement of secretion was observed even when the J-domain had a mutation in the HPD motif, which is necessary for J-protein-Hsp70 interactions, suggesting the phenomenon observed is independent on functional J-protein-Hsp70 interactions. This technology has great potential for not only enhancing the production of recombinant proteins, but also to treat conformational diseases such as cystic fibrosis, and Alpha-1 antitrypsin deficiency.
对于分泌蛋白来说，正确的蛋白质折叠不仅对于生物功能至关重要，对于分泌本身也是如此。折叠有问题的蛋白质会被困在内质网（ER）中，最终在细胞质中降解。在这项研究中，我们利用一种基于 DnaJ 蛋白序列的人工融合蛋白的共表达，该蛋白可以作为 HSP70 蛋白折叠系统中的共伴侣相互作用，与目标重组分泌蛋白共表达，以提高它们的产量和分泌。J 结构域序列或其片段与靶蛋白结合域连接，该靶蛋白结合域能够与靶蛋白序列的一部分结合。当与 J 结构域融合蛋白共表达时，许多靶蛋白的产量显著上调。令人惊讶的是，即使 J 结构域在 HPD 基序中发生突变，即 J 蛋白-Hsp70 相互作用所必需的突变，也观察到了分泌的增强，这表明观察到的现象独立于功能性 J 蛋白-Hsp70 相互作用。这项技术不仅具有提高重组蛋白产量的巨大潜力，而且还可以治疗囊性纤维化和α-1 抗胰蛋白酶缺乏等构象疾病。
