RESUMEN
The yeast Saccharomyces cerevisiae is a widely used cell factory for protein production. Increasing the protein production capacity of a yeast strain may be beneficial for obtaining recombinant proteins as a product or exerting its competence in consolidated bioprocessing. However, heterologous protein expression usually imposes stress on cells. Improving the cell's ability to cope with stress enhances protein yield. HAC1 is a key transcription factor in the unfolded protein response (UPR). In this study, several genes related to the UPR signal pathway, including unfolded protein sensing, HAC1 mRNA splicing, mRNA ligation, mRNA decay, translation, and Hac1p degradation, were selected as targets to engineer yeast strains. The final engineered strain produced α-amylase 3.3-fold, and human serum albumin 15.3-fold, greater than that of the control strain. Key regulation and metabolic network changes in the engineered strains were identified by transcriptome analysis and physiological characterizations. This study demonstrated that cell engineering with genes relevant to the key node HAC1 in UPR increased protein secretion substantially. The verified genetic modifications of this study provide useful targets in the construction of yeast cell factories for efficient protein production.
Asunto(s)
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Humanos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Ingeniería Celular , Respuesta de Proteína Desplegada/genética , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
High-entropy alloys (HEAs) hold promise as candidate structural materials in future nuclear energy systems. Body-centred cubic V-Ti-Ta-Nb HEAs have received extensive attention due to their excellent mechanical properties. In this work, the Finnis-Sinclair interatomic potential for quaternary V-Ti-Ta-Nb HEAs has been fitted based on the defect properties obtained with the density functional theory (DFT) calculations. The new potential for Nb accurately reproduces the vacancy formation energy, vacancy migration energy and interstitial formation energy. The typical radiation defect properties predicted by the alloy potential were consistent with the DFT results, including the binding energies between substitutional solute atoms, the binding energy between substitutional atoms and vacancies, and the formation energy of interstitial solute atoms. In addition, the mixing enthalpies of the alloys were also consistent with the DFT results. The present potential can also describe reasonably the collision cascade process of quaternary V-Ti-Ta-Nb HEAs.