Establishment of a patient-derived organoid model and living biobank for nasopharyngeal carcinoma.

Background: Recurrent nasopharyngeal carcinoma (NPC) remains a major challenge for clinicians and scientists. Tumor organoid is a revelational disease model that highly resembled the heterogeneity and histopathological characteristics of original tumors. This study aimed to optimize the modeling process of patient-derived NPC organoids (NPCOs), and establish a living-biobank of NPCs to study the mechanism and explore the more effective treatment of the disease.

Structural insights into DNA binding domain of vancomycin-resistance-associated response regulator in complex with its promoter DNA from Staphylococcus aureus.

In Staphylococcus aureus, vancomycin-resistance-associated response regulator (VraR) is a part of the VraSR two-component system, which is responsible for activating a cell wall-stress stimulon in response to an antibiotic that inhibits cell wall formation. Two VraR-binding sites have been identified: R1 and R2 in the vraSR operon control region. However, the binding of VraR to a promoter DNA enhancing downstream gene expression remains unclear.

Fragment-Directed Random Mutagenesis by the Reverse Kunkel Method.

Two fundamentally different approaches are routinely used for protein engineering: user-defined mutagenesis and random mutagenesis, each with its own strengths and weaknesses. Here, we invent a unique mutagenesis protocol, which combines the advantages of user-defined mutagenesis and random mutagenesis. The new method, termed the reverse Kunkel method, allows the user to create random mutations at multiple specified regions in a one-pot reaction.

Structural basis for promoter DNA recognition by the response regulator OmpR.

OmpR, a response regulator of the EnvZ/OmpR two-component system (TCS), controls the reciprocal regulation of two porin proteins, OmpF and OmpC, in bacteria. During signal transduction, OmpR (OmpR-FL) undergoes phosphorylation at its conserved Asp residue in the N-terminal receiver domain (OmpRn) and recognizes the promoter DNA from its C-terminal DNA-binding domain (OmpRc) to elicit an adaptive response. Apart from that, OmpR regulates many genes in Escherichia coli and is important for virulence in several pathogens.

Direct Antibody Isolation on Cells Using Affinity-Tag-Guided Proximity Selection.

Traditional antibody generation, using either phage display or animal immunization, relies on purified antigens. Many membrane proteins, such as G protein-coupled receptors, solute carriers, or ion channels, are important drug targets but very challenging for the formation of antibodies due to the difficulty of protein purification. Whole-cell panning is an alternative approach for generating antibodies without the need for antigen purification.

miR-223-3p Inhibits Antigen Endocytosis and Presentation and Promotes the Tolerogenic Potential of Dendritic Cells through Targeting Mannose Receptor Signaling and Rhob.

Background: The role of miR-223-3p in dendritic cells (DCs) is unknown. This study is aimed at investigating the effect of miR-223-3p on the antigen uptake and presentation capacities of DCs and the underlying molecular mechanism.

Methods: FITC-OVA antigen uptake and cell surface markers in bone marrow-derived DCs (BMDCs) were analyzed by flow cytometry.

Turning the RING domain protein MdmX into an active ubiquitin-protein ligase.

The related RING domain proteins MdmX and Mdm2 are best known for their role as negative regulators of the tumor suppressor p53. However, although Mdm2 functions as a ubiquitin ligase for p53, MdmX does not have appreciable ubiquitin ligase activity. In this study, we performed a mutational analysis of the RING domain of MdmX, and we identified two distinct regions that, when replaced by the respective regions of Mdm2, turn MdmX into an active ubiquitin ligase for p53.