Chloroplasts are semi-autonomous organelles, with more than 95% of their proteins encoded by the nuclear genome. The chloroplast-to-nucleus retrograde signals are critical for the nucleus to coordinate its gene expression for optimizing or repairing chloroplast functions in response to changing environments. In chloroplasts, the pentatricopeptide-repeat protein GENOMES UNCOUPLED 1 (GUN1) is a master switch that senses aberrant physiological states, such as the photooxidative stress induced by norflurazon (NF) treatment, and represses the expression of photosynthesis-associated nuclear genes (PhANGs). However, it is largely unknown how the retrograde signal is transmitted beyond GUN1. In this study, a protein GUN1-INTERACTING PROTEIN 1 (GIP1), encoded by At3g53630, was identified to interact with GUN1 by different approaches. We demonstrated that GIP1 has both cytosol and chloroplast localizations, and its abundance in chloroplasts is enhanced by NF treatment with the presence of GUN1. Our results suggest that GIP1 and GUN1 may function antagonistically in the retrograde signaling pathway.
The continuously arising of SARS-CoV-2 variants has been posting a great threat to public health safety globally, from B.1.17 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta) to B.1.1.529 (Omicron). The emerging or reemerging of the SARS-CoV-2 variants of concern is calling for the constant monitoring of their epidemics, pathogenicity and immune escape. In this study, we aimed to characterize replication and pathogenicity of the Alpha and Delta variant strains isolated from patients infected in Laos. The amino acid mutations within the spike fragment of the isolates were determined via sequencing. The more efficient replication of the Alpha and Delta isolates was documented than the prototyped SARS-CoV-2 in Calu-3 and Caco-2 cells, while such features were not observed in Huh-7, Vero E6 and HPA-3 cells. We utilized both animal models of human ACE2 (hACE2) transgenic mice and hamsters to evaluate the pathogenesis of the isolates. The Alpha and Delta can replicate well in multiple organs and cause moderate to severe lung pathology in these animals. In conclusion, the spike protein of the isolated Alpha and Delta variant strains was characterized, and the replication and pathogenicity of the strains in the cells and animal models were also evaluated. 相似文献
A cytoplasmic serine􊄯thronine protein kinase gene (OsSTK), had been cloned from Oryza genus. It was found high conservative and constitutive expression in Oryza. OsSTK gene had two exons, separated by 114 bp short intron. The open reading frame of OsSTK gene that predicted encoded a 419 amino acids protein . The amino acid sequence of OsSTK had low identities ( less than 53% ) with any other known protein kinase . The phylogenetic tree based on the partial DNA sequences of OsSTK from different species and types of wild rice and cultivated rice, was close to the taxation system ofrice . Interestingly , OsSTK had a serine, including basic amino acids and charged amino acids abundant polypeptide with a “GDGDGDGDG”sequence at N- terminal that had not been found in any other genes. OsSTK may play dual specificity that phosphorylates both serine􊄯thronine and tyrosone, because the amino acids module of VIb , VIII and XI catalytic domain have both the serine􊄯thronine and tyrosine kinase characters . 相似文献
