Background: An outbreak of pneumonia associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city and then to other city. It is very urgent to delineate the epidemiological and clinical characteristics of these affected patients. Methods: To investigate the epidemiological characteristics of the COVID-19, we describe a case series of 459 patients with con rmed COVID-19 in WZ of China from January 27 to February 12, 2020. Results: The median age of all patients was 48.0 years, and 46.8% were females. 37.5% of patients had a history of residence in Wuhan. Fever (72.1%) and cough (43.6%) were the most frequent symptoms. In addition, three kinds of unconventional cases were observed, in which included 4.4% con rmed virus carrier who were asymptomatic, 7.8% con rmed patients who had no link to Wuhan city but contact with individuals from Wuhan without any symptoms at the time of contact, and 10.7% con rmed patients who had no link to Wuhan city nor a history of intimate contact with patients or individuals from Wuhan without any symptoms, respectively. Conclusion: Our ndings presented the possibility of asymptomatic carriers affected with SARS-CoV-2, and this phenomenon suggested that chances of uncontrollable transmission in the larger population might be higher than formerly estimated, and transmission by these three kinds of unconventional patients in WZ may be one of the characteristics of infection in other Chinese cities outside the Wuhan epidemic area.

Networks of protein interactions coordinate cellular functions. We describe a bimolecular fluorescence complementation (BiFC) assay for determination of the locations of protein interactions in living cells. This approach is based on complementation between two nonfluorescent fragments of the yellow fluorescent protein (YFP) when they are brought together by interactions between proteins fused to each fragment. BiFC analysis was used to investigate interactions among bZIP and Rel family transcription factors. Regions outside the bZIP domains determined the locations of bZIP protein interactions. The subcellular sites of protein interactions were regulated by signaling. Cross-family interactions between bZIP and Rel proteins affected their subcellular localization and modulated transcription activation. These results attest to the general applicability of the BiFC assay for studies of protein interactions.

The specificity of biological regulatory mechanisms relies on selective interactions between different proteins in different cell types and in response to different extracellular signals. We describe a bimolecular fluorescence complementation (BiFC) approach for the simultaneous visualization of multiple protein interactions in the same cell. This approach is based on complementation between fragments of fluorescent proteins with different spectral characteristics. We have identified twelve new bimolecular fluorescent complexes that correspond to seven different spectral classes. Bimolecular complex formation between fragments of different fluorescent proteins did not differentially affect the dimerization efficiency or subcellular sites of interactions between the bZIP domains of Fos and Jun. Multicolor BiFC enables visualization of interactions between different proteins in the same cell and comparison of the efficiencies of complex formation among alternative interaction partners.Networks of protein interactions mediate cellular responses to environmental stimuli and direct the execution of developmental programs. Each protein typically has a large number of alternative interaction partners, and the selectivity of these interactions determines the developmental potential of the cell and its responses to extracellular stimuli. We recently described a new approach for the visualization of protein interactions in living cells designated bimolecular fluorescence complementation (BiFC) analysis 1 . The BiFC approach is based on the formation of a fluorescent complex by fragments of the yellow fluorescent protein (YFP) brought together by the association of two interaction partners fused to the fragments. This approach enables visualization of the subcellular sites of protein interactions under conditions that closely reflect the normal physiological environment.Molecular engineering of the green fluorescent protein (GFP) has produced several variants with altered spectral characteristics 2 . These variants allow simultaneous visualization of the distributions of multiple proteins in living cells. Moreover, fluorescence resonance energy transfer (FRET) between different variants enables analysis of interactions between individual pairs of proteins in living cells 3, 4 . Thus far, it has not been possible to visualize multiple interactions in the same cell.Selected fragments of many proteins can associate to produce functional bimolecular complexes. Such bimolecular complementation provides a convenient approach for detection of protein interactions in cells if the protein fragments can associate only when they are brought together by interaction partners fused to the fragments 1, 5-9 . The unique characteristic of the BiFC approach is that the bright intrinsic fluorescence of the bimolecular complex allows direct * To whom correspondence should be addressed:Tel: (734) FAX: (734) RESULTSThe spectral characteristics of bimolecular fluorescent complexes formed by fragments of YFP were virtually identical t...