Project description:Legume GRAS-type transcription factors NSP1 and NSP2 are essential for Rhizobium Nod factor-induced nodulation. Both proteins are considered to be Nod factor response factors regulating gene expression upon symbiotic signalling. However, legume NSP1 and NSP2 can be functionally replaced by non-legume orthologs; including rice (Oryza sativa) OsNSP1 and OsNSP2. This shows that both proteins are functionally conserved in higher plants, suggesting an ancient function that was conserved during evolution. Here we show that NSP1 and NSP2 are indispensable for strigolactone biosynthesis in the legume Medicago truncatula as well as rice. Mutant nsp1-nsp2 plants hardly produce strigolactones. The lack of strigolactone biosynthesis coincides with strongly reduced DWARF27 expression in both species. Rice and Medicago represent distinct phylogenetic lineages that split ~150 million years ago. Therefore we conclude that regulation of strigolactone biosynthesis by NSP1 and NSP2 is an ancestral function conserved in higher plants. Since strigolactone biosynthesis is highly regulated by environmental conditions like phosphate starvation, NSP1 and NSP2 will be important tools in future studies on the molecular mechanisms by which environmental sensing is translated into regulation of strigolactone biosynthesis. As NSP1 and NSP2 are single copy genes in legumes, it implies that a single protein complex fulfills a dual regulatory function of different downstream targets; symbiotic and non-symbiotic, respectively. Three biological replications are used for roots of wild type A17, nsp1 and nsp2 mutant plants
Project description:This study investigated the immunological function of PRRSV Nsp1 by ectopic expression of PRRSV Nsp1 in 3D4/31 cell line. Identifying the functional role of PRRSV Nsp1 associated with host cell modulation may provide better knowledge about the pathogenesis of PRRS (Porcine reproductive and respiratory syndrome).
Project description:Legume GRAS-type transcription factors NSP1 and NSP2 are essential for Rhizobium Nod factor-induced nodulation. Both proteins are considered to be Nod factor response factors regulating gene expression upon symbiotic signalling. However, legume NSP1 and NSP2 can be functionally replaced by non-legume orthologs; including rice (Oryza sativa) OsNSP1 and OsNSP2. This shows that both proteins are functionally conserved in higher plants, suggesting an ancient function that was conserved during evolution. Here we show that NSP1 and NSP2 are indispensable for strigolactone biosynthesis in the legume Medicago truncatula as well as rice. Mutant nsp1-nsp2 plants hardly produce strigolactones. The lack of strigolactone biosynthesis coincides with strongly reduced DWARF27 expression in both species. Rice and Medicago represent distinct phylogenetic lineages that split ~150 million years ago. Therefore we conclude that regulation of strigolactone biosynthesis by NSP1 and NSP2 is an ancestral function conserved in higher plants. Since strigolactone biosynthesis is highly regulated by environmental conditions like phosphate starvation, NSP1 and NSP2 will be important tools in future studies on the molecular mechanisms by which environmental sensing is translated into regulation of strigolactone biosynthesis. As NSP1 and NSP2 are single copy genes in legumes, it implies that a single protein complex fulfills a dual regulatory function of different downstream targets; symbiotic and non-symbiotic, respectively.
Project description:Extensive remodeling of host gene expression by coronaviruses nsp1 proteins is a well-documented and conserved aspect of coronavirus-host takeover. Using comparative transcriptomics we investigate the diversity of transcriptional targets between nsp1 proteins between α- and β- coronaviruses. Additionally, Affinity Purification Mass-Spectrometry was implemented to identify common and divergent interactors between the nsp1 proteins. While we detected widespread RNA destabilization between the different nsp1s, closely related nsp1 showed little similarities in clustering of targeted genes. Partial overlapping transcriptional targeting between α-CoV 229E and MERS nsp1 may suggest a shared similar targeting mechanism, as MERS nsp1 preferentially targets nuclear transcripts. Our interactome data shows great variance between nsp1 interactions, with 229E nsp1, the smallest tested here, interacts with the most host proteins, while MERS nsp1 only engaged with a few. While nsp1 is a rather well-conserved protein with consistent functions across different coronaviruses, its precise effects on host cells is virus-specific.
Project description:NSP1 is a major shutoff factor of the SARS-CoV-2 coronavirus, which is responsible for the COVID-19 pandemic. The functions of NSP1 and its contribution to SARS-CoV-2 propagation is not well understood. We tackled these questions utilizing methods such as RNA sequencing, ribosome profiling, and SLAMseq.
Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) selectively suppresses the translation of host mRNA to inhibit immune responses and promote viral proliferation. Non-structural protein 1 (Nsp1), the key factor of this process, binds to the mRNA entry channel of the 40S ribosomal subunit. While it was thought that this interaction prevented translation initiation, Nsp1 may affect other translational processes. However, this potential was not fully understood. Here, we showed that Nsp1 binds to elongating 80S through the interaction between the C-terminal domain and the mRNA entry channel. Although this interaction does not alter the elongation rate, we demonstrated that Nsp1 counteracts ribosome-associated quality control (RQC). These findings expand the translational regulator role of Nsp1 beyond a mere initiation inhibitor.