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Biology subjects

Ziegelmueller, J.

Publications and source records attributed to Ziegelmueller, J..

2 recordsLinked to original sources

Efficient cell-free translation from diverse human cell types

MotivationThe difficulties in producing cell-free translation systems from different cell types limit the ability to study regulatory mechanisms that depend on different biological contexts. Developing systems tailored to diverse cell types would be instrumental in investigating cell-type-specific translational control, co- and post-translational modifications, and viral manipulation strategies. Our method addresses this gap by providing a scalable and adaptable solution for producing high-quality lysates that reflect the specific needs of different cell types. SummaryCell-free translation systems are indispensable for studying protein synthesis, enabling researchers to explore translational regulation across different cell types. Here, we present a scalable method for preparing translation-competent lysates from a range of frequently used human cell lines using dual centrifugation. We optimized lysis conditions for adherent and suspension cells, producing high-quality lysates from HEK-293 (adherent and in suspension), HeLa, SH-SY5Y, and U2OS cells. Our results demonstrate that cell-specific factors influence translation efficiency, with adherent HeLa cells showing the highest activity. We also observed that sensitivity to lysis conditions varies between cell lines, underscoring the importance of fine-tuning parameters for efficient protein production. Our method provides a robust and adaptable approach for generating cell-type-specific lysates, broadening the application of in vitro translation systems in studying translational mechanisms.

biochemistry↗

Universal features of Nsp1-mediated translational shutdown by coronaviruses

Nonstructural protein 1 (Nsp1) produced by coronaviruses shuts down host protein synthesis in infected cells. The C-terminal domain of SARS-CoV-2 Nsp1 was shown to bind to the small ribosomal subunit to inhibit translation, but it is not clear whether this mechanism is broadly used by coronaviruses, whether the N-terminal domain of Nsp1 binds the ribosome, or how Nsp1 specifically permits translation of viral mRNAs. Here, we investigated Nsp1 from three representative Betacoronaviruses - SARS-CoV-2, MERS-CoV, and Bat-Hp-CoV - using structural, biophysical, and biochemical assays. We revealed a conserved mechanism of host translational shutdown across the three coronaviruses. We further demonstrated that the N-terminal domain of Bat-Hp-CoV Nsp1 binds to the decoding center of the 40S subunit, where it would prevent mRNA and eIF1A binding. Structure-based biochemical experiments identified a conserved role of these inhibitory interactions in all three coronaviruses and showed that the same regions of Nsp1 are responsible for the preferential translation of viral mRNAs. Our results provide a mechanistic framework to understand how Betacoronaviruses overcome translational inhibition to produce viral proteins.

biochemistry↗