* indicates significant effect of drought on the trait. Growth stages were characterized by the Fehr and Caviness scale [11]. Experiments were carried on the indeterminate cultivar, Weber.

YchF proteins are a group of mysterious but ubiquitous unconventional G-proteins found in all kingdoms of life except Archaea. Their functions have been documented in microorganisms, protozoa and human, but those of plant YchF homologues are largely unknown. Our group has previously shown that OsYchF1 and its interacting protein, OsGAP1, play opposite roles in plant defense responses. OsGAP1 was found to stimulate the GTPase/ATPase activities of OsYchF1 and regulate its subcellular localization. In this report, we demonstrate that both OsYchF1 and OsGAP1 are localized mainly in the cytosol under NaCl treatment. The ectopic expression of OsYchF1 in transgenic Arabidopsis thaliana leads to reduced tolerance towards salinity stress, while the ectopic expression of OsGAP1 has the opposite effect. Similar results were also obtained with the Arabidopsis homologues, AtYchF1 and AtGAP1, by using AtGAP1 overexpressors and underexpressors, as well as an AtYchF1-knockdown mutant. OsYchF1 and OsGAP1 also exhibit highly significant effects on salinity-induced oxidative stress tolerance. The expression of OsYchF1 suppresses the anti-oxidation enzymatic activities and increases lipid peroxidation in transgenic Arabidopsis, and leads to the accumulation of reactive oxygen species (ROS) in tobacco BY-2 cells, while the ectopic expression of OsGAP1 has the opposite effects in these two model systems.

G proteins are involved in almost all aspects of the cellular regulatory pathways through their ability to bind and hydrolyze GTP. The YchF subfamily, interestingly, possesses the unique ability to bind both ATP and GTP, and is possibly an ancestral form of G proteins based on phylogenetic studies and is present in all kingdoms of life. However, the biological significance of such a relaxed ligand specificity has long eluded researchers. Here, we have elucidated the different conformational changes caused by the binding of a YchF homolog in rice (OsYchF1) to ATP versus GTP by X-ray crystallography. Furthermore, by comparing the 3D relationships of the ligand position and the various amino acid residues at the binding sites in the crystal structures of the apo-bound and ligand-bound versions, a mechanism for the protein's ability to bind both ligands is revealed. Mutation of the noncanonical G4 motif of the OsYchF1 to the canonical sequence for GTP specificity precludes the binding/hydrolysis of ATP and prevents OsYchF1 from functioning as a negative regulator of plant-defense responses, while retaining its ability to bind/hydrolyze GTP and its function as a negative regulator of abiotic stress responses, demonstrating the specific role of ATP-binding/hydrolysis in disease resistance. This discovery will have a significant impact on our understanding of the structure-function relationships of the YchF subfamily of G proteins in all kingdoms of life.G TP-binding proteins (G proteins) play important roles in diverse fundamental biological processes in living organisms, including signal transduction, cell division, development, intracellular transport, translation, and others (1, 2). The functions and working mechanisms of some ancestral G proteins, which are believed to play essential roles in cellular processes, are still unknown. One such group is the Obg family, which features an N-terminal glycine-rich sequence, followed by a G domain for nucleotide binding and a C-terminal TGS (ThrRS, GTPase, and SpoT) domain that has nucleic acid binding affinity (3).A unique subgroup within the Obg family, the YchF proteins, exhibit relaxed nucleotide-binding specificities (4-6). All G proteins contain a G domain (composed of the G1-G5 motifs) for GTP binding and hydrolysis (4). The G4 motif (canonical sequence: NKxD) confers the specificity for binding GTP (4). In YchFs, the noncanonical G4 sequence (NxxE) is correlated with the loss of nucleotide-binding specificities (4, 5). In some cases, ATP is the preferred ligand (4, 5). However, the physiological significance of the ancient and evolutionarily conserved YchF proteins having the relaxed binding specificities for both ATP and GTP is still unknown.Only a few reports touch on the biological functions of YchF proteins and most focus on human and microorganisms (7-9). The YchF proteins may play a role in iron utilization and regulation of the Ton system in Brucella melitensis (7), and in the growth of the procyclic forms of Trypanosoma cruzi (5). The human YchF homolog hOLA...

The coronavirus disease 2019 (COVID‐19) is a highly infectious disease caused by SARS‐CoV‐2. Since its first report in December 2019, COVID‐19 has evolved into a global pandemic causing massive healthcare and socioeconomic challenges. HLA system is critical in mediating anti‐viral immunity and recent studies have suggested preferential involvement of HLA‐B in COVID‐19 susceptibility. Here, by investigating the HLA‐B genotypes in 190 unrelated Chinese patients with confirmed COVID‐19, we identified a significant positive association between the B22 serotype and SARS‐CoV‐2 infection (p = 0.002, Bonferroni‐corrected p = 0.032). Notably, the B22 serotype has been consistently linked to susceptibility to other viral infections. These data not only shed new insights into SARS‐CoV‐2 pathogenesis and vaccine development but also guide better infection prevention/control.

Platelet concentrates (PC) generally refers to a group of products that are prepared from autologous blood intended to enhance healing activities. PC therapy is now very popular in treating musculoskeletal injuries; however, inconsistent clinical results urge the need to understand the working mechanism of PC. It is generally believed that the platelet-derived bioactive factors are the active constituents, and their bioavailability in the vicinity of the lesion sites determines the treatment efficacies. Therefore, the composition, localisation, and duration of the action of PC would be key determinants. In this review, we discuss how different preparations and delivery methods of PC would affect the treatment outcomes with respect to clinical evidence about PC therapy for osteoarthritis, tendinopathies, rotator cuff tears, anterior cruciate ligament injuries, and bone fractures. This review can be used as a quick guide for the use of PC therapy and provide insights for the further optimisation of the therapy in the near future.

Communication skills can be effectively taught to, and improved among experienced Chinese doctors by a combination of large-class teaching and medium-sized group practice with feedback, and without intensive individual supervision.

Background: OsGAP1, a plant-specific C2-domain protein, binds to phospholipids and an unconventional G-protein (OsYchF1). Results: We solved the OsGAP1 structure and performed site-directed mutagenesis to identify two functional surfaces for binding to phospholipids versus OsYchF1. Conclusion:Interactions with phospholipids and OsYchF1 play important roles in the functions of OsGAP1. Significance: Our data advance the understanding of the structure-function relationship of C2-domain proteins.

Prefibrotic primary myelofibrosis (Pre‐PMF) has been classified as a separate entity of myeloproliferative neoplasms (MPNs). Pre‐PMF is clinically heterogeneous but a specific prognostic model is lacking. Gene mutations have emerged as useful tools for stratification of myelofibrosis patients. However, there have been limited studies comprehensively investigating the mutational spectrum and its clinicopathological significance in pre‐PMF subjects. In this study, we addressed these issues by profiling the mutation status of 141 genes in 172 Chinese MPN patients including 72 pre‐PMF cases. Our findings corroborated the clinical/molecular distinctiveness of pre‐PMF and suggested a refined risk classification strategy for this entity.