Synthetic receptors targeted to the secretory pathway often fail to exhibit the expected activity due to post-translational modifications (PTMs) and/or improper folding. Here, we engineered synthetic receptors that reside in the cytoplasm, inside the endoplasmic reticulum (ER), or on the plasma membrane through orientation adjustment of the receptor parts and by elimination of dysfunctional PTMs sites. The cytoplasmic receptors consist of split-TEVp domains that reconstitute an active protease through chemically-induced dimerization (CID) that is triggered by rapamycin, abscisic acid, or gibberellin.
View Article and Find Full Text PDFMultiple myeloma (MM) causes approximately 20% of deaths from blood cancers. Notwithstanding significant therapeutic progress, such as with proteasome inhibitors (PIs), MM remains incurable due to the development of resistance. mTORC1 is a key metabolic regulator, which frequently becomes dysregulated in cancer.
View Article and Find Full Text PDFThe endoplasmic reticulum (ER) is a dynamic organelle that responds to demand in secretory proteins by undergoing expansion. The mechanisms that control the homeostasis of ER size and function involve the activation of the unfolded protein response (UPR). The UPR plays a role in various effector functions of immune cells.
View Article and Find Full Text PDFSynthetic biology has made it possible to engineer mammalian cells for on-demand delivery of therapeutic agents, providing therapeutic solutions for chronic or intractable diseases. Currently, most of the engineered therapeutic cells are regulated by the administration of exogenous inducers, but the need for repeated administration of these xenobiotics is problematic from the viewpoints of patients' compliance and quality of life, as well as possible side effects. Recently, synthetic biologists started to address these issues by constructing autonomous, closed-loop therapeutic cells, often referred to as designer cells.
View Article and Find Full Text PDFRapid insulin release plays an essential role in maintaining blood-glucose homeostasis in mammalians. Patients diagnosed with type-I diabetes mellitus experience chronic and remarkably high blood-sugar levels, and require lifelong insulin injection therapy, so there is a need for more convenient and less invasive insulin delivery systems to increase patients' compliance and also to enhance their quality of life. Here, an endoplasmic-reticulum-localized split sec-tobacco etch virus protease (TEVp)-based rapamycin-actuated protein-induction device (RAPID) is engineered, which is composed of the rapamycin-inducible dimerization domains FK506 binding protein (FKBP) and FKBP-rapamycin binding protein fused with modified split sec-TEVp components.
View Article and Find Full Text PDFSchizophrenia is a mental disease that results in decreased life expectancy and well-being by promoting obesity and sedentary lifestyles. Schizophrenia is treated by antipsychotic drugs. Although the second-generation antipsychotics (SGA), Olanzapine and Aripiprazole, are more effective in treating schizophrenia, they display a higher risk of metabolic side effects, mostly by development of diabetes and insulin resistance, weight gain, and dyslipidemia.
View Article and Find Full Text PDFThe integrated stress response (ISR) converges on eIF2α phosphorylation to regulate protein synthesis. ISR is activated by several stress conditions, including endoplasmic reticulum (ER) stress, executed by protein kinase R-like endoplasmic reticulum kinase (PERK). We report that ER stress combined with ISR inhibition causes an impaired maturation of several tyrosine kinase receptors (RTKs), consistent with a partial block of their trafficking from the ER to the Golgi.
View Article and Find Full Text PDFThe B7 family member, B7H6, is a ligand for the natural killer cell receptor NKp30. B7H6 is hardly expressed on normal tissues, but undergoes upregulation on different types of tumors, implicating it as an attractive target for cancer immunotherapy. The molecular mechanisms that control B7H6 expression are poorly understood.
View Article and Find Full Text PDFRecombinant glycoproteins produced in mammalian cells are clinically indispensable drugs used to treat a broad spectrum of diseases. Their bio-manufacturing process is laborious, time consuming, and expensive. Investment in expediting the process and reducing its cost is the subject of continued research.
View Article and Find Full Text PDFRapidly proliferating cells reshape their metabolism to satisfy their ever-lasting need for cellular building blocks. This phenomenon is exemplified in certain malignant conditions such as cancer but also during embryonic development when cells rely heavily on glycolytic metabolism to exploit its metabolic intermediates for biosynthetic processes. How cells reshape their metabolism is not fully understood.
View Article and Find Full Text PDFIRE1, PERK, and ATF6 are the three transducers of the mammalian canonical unfolded protein response (UPR). GSK2606414 is a potent inhibitor of PERK, while KIRA6 inhibits the kinase activity of IRE1. Both molecules are frequently used to probe the biological roles of the UPR in mammalian cells.
View Article and Find Full Text PDFProtein translation has emerged as a critical bottleneck for overall productivity of biological molecules. An augmentation of protein translation can be achieved by cell line engineering or by sophisticated vector design. However, for industrial process development purposes, identification of media additives that promote translation will be of great value, obviating the generation of new host platforms.
View Article and Find Full Text PDFThe new reactivity of α,β-unsaturated enaminones driven by their "dual electronic attitude" is reported. We introduce unexplored, α-enaminone synthones and reveal the unusual functionalities of these building blocks. The feasibility of this new concept is demonstrated in the direct functionalization of enaminone precursors, such as alkylation; 1,2- 1,3-, or 1,4-addition; and C-O bond formation.
View Article and Find Full Text PDFAn optimized biomanufacturing process in mammalian cells is contingent on the ability of the producing cells to reach high viable cell densities. In addition, at the peak of growth, cells need to continue producing the biological entity at a consistent quality. Thus, engineering cells with robust growth performance and resilience to variable stress conditions is highly desirable.
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