Survival Factor A (SvfA) Contributes to Aspergillus nidulans Pathogenicity.

Survival factor A (SvfA) in Aspergillus nidulans plays multiple roles in growth and developmental processes. It is a candidate for a novel VeA-dependent protein involved in sexual development. VeA is a key developmental regulator in Aspergillus species that can interact with other velvet-family proteins and enter into the nucleus to function as a transcription factor. In yeast and fungi, SvfA-homologous proteins are required for survival under oxidative and cold-stress conditions. To assess the role of SvfA in virulence in A. nidulans, cell wall components, biofilm formation, and protease activity were evaluated in a svfA-gene-deletion or an AfsvfA-overexpressing strain. The svfA-deletion strain showed decreased production of ß-1,3-glucan in conidia, a cell wall pathogen-associated molecular pattern, with a decrease in gene expression for chitin synthases and ß-1,3-glucan synthase. The ability to form biofilms and produce proteases was reduced in the svfA-deletion strain. We hypothesized that the svfA-deletion strain was less virulent than the wild-type strain; therefore, we performed in vitro phagocytosis assays using alveolar macrophages and analyzed in vivo survival using two vertebrate animal models. While phagocytosis was reduced in mouse alveolar macrophages challenged with conidia from the svfA-deletion strain, the killing rate showed a significant increase with increased extracellular signal-regulated kinase ERK activation. The svfA-deletion conidia infection reduced host mortality in both T-cell-deficient zebrafish and chronic granulomatous disease mouse models. Taken together, these results indicate that SvfA plays a significant role in the pathogenicity of A. nidulans.

Expression and purification of intracrine human FGF 11 and study of its FGFR-dependent biological activity.

Fibroblast growth factor 11 (FGF11) is one of intracrine FGFs (iFGFs), which function within cells. Unlike canonical FGFs, FGF11 remains intracellularly and plays biological roles in FGF receptor (FGFR)-independent manner. Here, we established an expression system of recombinant FGF11 proteins in E. coli and investigated whether the extracellular administration of FGF11 can activate cellular signaling. Human FGF11 has two isoforms, FGF11a and FGF11b, depending on the presence of nuclear localization sequences (NLSs) in the N-terminus. Because these two isoforms are unstable, we prepared an FGF11a-Mut by substituting three cysteine residues in the NLS with serine and FGF11b-ΔC with C-terminal truncation. The introduction of mutation in the NLS improved the solubility of FGF11 prepared from E. coli. Exogenous addition of FGF11b and FGF11b-ΔC to BALB3T3 increased cell proliferation, while FGF11a-Mut exerted no effect. FGF11b-ΔC showed higher cell proliferation activity and FGFR signaling than FGF11b. The cell-proliferating activities of FGF11b and FGF11b-ΔC were blocked by an FGFR1 inhibitor or a recombinant FGFR1, confirming the FGFR1-dependent extracellular activity of FGF11b. The analysis of circular dichroism suggested that the C-terminus of FGF11 has an α-helical structure, which may affect its interaction with FGFR1. These results suggest that the N-and C-terminus of recombinant FGF11 are involved in the activation of FGFR1. The above results provide novel insights into the function and mechanism of FGF11 that may aid the development of useful ligands for FGFR regulation.

Spatiotemporal coordination of the RSF1-PLK1-Aurora B cascade establishes mitotic signaling platforms.

The chromatin remodeler RSF1 enriched at mitotic centromeres is essential for proper chromosome alignment and segregation and underlying mechanisms remain to be disclosed. We here show that PLK1 recruitment by RSF1 at centromeres creates an activating phosphorylation on Thr236 in the activation loop of Aurora B and this is indispensable for the Aurora B activation. In structural modeling the phosphorylated Thr236 enhances the base catalysis by Asp200 nearby, facilitating the Thr232 autophosphorylation. Accordingly, RSF1-PLK1 is central for Aurora B-mediated microtubule destabilization in error correction. However, under full microtubule-kinetochore attachment RSF1-PLK1 positions at kinetochores, halts activating Aurora B and phosphorylates BubR1, regardless of tension. Spatial movement of RSF1-PLK1 to kinetochores is triggered by Aurora B-mediated phosphorylation of centromeric histone H3 on Ser28. We propose a regulatory RSF1-PLK1 axis that spatiotemporally controls on/off switch on Aurora B. This feedback circuit among RSF1-PLK1-Aurora B may coordinate dynamic microtubule-kinetochore attachment in early mitosis when full tension yet to be generated.

Facilitators and barriers to smoking cessation among minority men using the behavioral-ecological model and Behavior Change Wheel: A concept mapping study.

BACKGROUND AND AIM: Universal smoking cessation strategies are not always successful for minorities, among whom smoking is highly prevalent despite high intention to quit. This study identifies facilitators for smoking cessation, as perceived by minority male smokers, that can inform a culturally appropriate national plan for smoking prevention and cessation. METHODS: We conducted in 2013 a three-stage study among Arab minority male current and former smokers (ages 18-64) in Israel, among whom smoking is very high: first, a Concept Mapping (CM) study with 102 and 202 participants in the brainstorming, and sorting and rating phases respectively. Second, we assigned clusters identified in the CM study to contingency levels using the Behavioral Ecological Model (BEM). Third, we classified clusters into intervention functions and policies using the Behavior Change Wheel (BCW). FINDINGS: The CM study revealed 58 barriers and facilitators for smoking prevention and cessation that were sorted into 11 clusters by the participants. These clusters were analogous to four BEM level contingency of smoking (social, institutional, community and individual). We classified it into two main policy categories, based on the BCW: 1- restructuring the socio-political environment of smoking through affirmative government's policies towards Arab minority in Israel, and 2-developing a culturally appropriate plan for smoking cessation in Arab local authorities including: raising awareness about tobacco hazards; enforcing anti-smoking laws; strengthening community institutional action; providing smoking cessation services; considering raising prices for tobacco products, addressing psychological sources of smoking in Arab men. CONCLUSIONS: Our study revealed barriers, facilitators and contingencies of smoking prevention and cessation with two main policy action items among the Arab minority in Israel: changing the socio-political environment of smoking, and developing a culturally appropriate smoking prevention and cessation national plan. Our study framework can inform policies and culturally appropriate interventions for smoking prevention and cessation in other minorities.