Discovery and Identification of a Novel Tag of HlyA60 for Protein Active Aggregate Formation in Escherichia coli.

The strategy of active aggregation tag fusion expression with target proteins can solve the problems of restricted expression, inefficient purification, and laborious immobilization faced in the production of recombinant proteins in Escherichia coli. We localized a novel active aggregation peptide HlyA60 from the hemolysin A secretion system, which can effectively induce aggregate formation with satisfactory protein activities in E. coli after fusion expression with the protein of interest. Based on structural prediction and surface properties, the process of active aggregation of HlyA60 through electrostatic interactions and hydrophobic interactions was analyzed. To investigate the potential application of HlyA60 as an efficient aggregation tag, it was fused with acetyl xylan esterase and lipase A, separately. The resulting fusion proteins demonstrated active aggregation rates of 97.6 and 66.7%, respectively, leading to 1.9-fold and 1.7-fold increases in bacterial density at the end of fermentation. The AXE-HlyA60 fusion protein, which exhibited superior performance, was subjected to purification and immobilization. It was able to achieve column-free purification with an impressive 98.8% recovery and in situ immobilization; the immobilization enabled 30 cycles of reactions to take place with 85% residual activity maintained. Our findings provide a novel tool for efficiently producing recombinant proteins in E. coli.

DNA damage induced by CDK4 and CDK6 blockade triggers anti-tumor immune responses through cGAS-STING pathway.

CDK4/6 are important regulators of cell cycle and their inhibitors have been approved as anti-cancer drugs. Here, we report a STING-dependent anti-tumor immune mechanism responsible for tumor suppression by CDK4/6 blockade. Clinical datasets show that in human tissues, CDK4 and CDK6 are over-expressed and their expressions are negatively correlated with patients' overall survival and T cell infiltration. Deletion of Cdk4 or Cdk6 in tumor cells significantly reduce tumor growth. Mechanistically, we find that Cdk4 or Cdk6 deficiency contributes to an increased level of endogenous DNA damage, which triggers the cGAS-STING signaling pathway to activate type I interferon response. Knockout of Sting is sufficient to reverse and partially reverse the anti-tumor effect of Cdk4 and Cdk6 deficiency respectively. Therefore, our findings suggest that CDK4/6 inhibitors may enhance anti-tumor immunity through the STING-dependent type I interferon response.

Factors affecting the implementation of task-sharing interventions for perinatal depression in low- and middle-income countries: A systematic review and qualitative metasynthesis.

Background The vast majority of women with perinatal depression (PND) live in low- and middle-income countries (LMICs). Task sharing is an alternative delivery strategy to implement PND services. However, the exploration of influencing factors for task sharing in PND services is poor. Therefore, this study aimed to identify factors affecting LMICs to implement PND task-sharing interventions from the perspective of stakeholders and weigh their levels of evidence. Methods A comprehensive literature search was carried out through six English and Chinese databases on qualitative data. We used Critical Appraisal Skills Programme (CASP)/Meta Quality Appraisal Tool (MetaQAT) to appraise included studies, extracted data according to the Consolidated Framework for Implementation Research (CFIR), and assigned levels of confidence in the factors through Grading of Recommendations Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative research (GRADE-CERQual). Results 17 studies met the eligibility criteria, factors identified with high levels of evidence were coded to the CFIR constructs, including "Knowledge and Attitudes of Those Served by the Organization", "Available Resources", "Compatibility", "Access to knowledge and information", "Resources of Those Served by the Organization" and "Alignment". Conclusion This metasynthesis highlights task sharing in PND interventions is influenced by multiple factors. We synthesized and developed implementation recommendations for practice. Strategies must be actively developed to enable women and their families to enjoy the benefits of good perinatal mental health.

Consistency and variability of cocrystals containing positional isomers: the self-assembly evolution mechanism of supramolecular synthons of cresol-piperazine.

The disposition of functional groups can induce variations in the nature and type of interactions and hence affect the molecular recognition and self-assembly mechanism in cocrystals. To better understand the formation of cocrystals on a molecular level, the effects of disposition of functional groups on the formation of cocrystals were systematically and comprehensively investigated using cresol isomers (o-, m-, p-cresol) as model compounds. Consistency and variability in these cocrystals containing positional isomers were found and analyzed. The structures, molecular recognition and self-assembly mechanism of supramolecular synthons in solution and in their corresponding cocrystals were verified by a combined experimental and theoretical calculation approach. It was found that the heterosynthons (heterotrimer or heterodimer) combined with O-H⋯N hydrogen bonding played a significant role. Hirshfeld surface analysis and computed interaction energy values were used to determine the hierarchical ordering of the weak interactions. The quantitative analyses of charge transfers and molecular electrostatic potential were also applied to reveal and verify the reasons for consistency and variability. Finally, the molecular recognition, self-assembly and evolution process of the supramolecular synthons in solution were investigated. The results confirm that the supramolecular synthon structures formed initially in solution would be carried over to the final cocrystals, and the supramolecular synthon structures are the precursors of cocrystals and the information memory of the cocrystallization process, which is evidence for classical nucleation theory.