The signaling pathway from phosphoinositide 3-kinase to the protein kinase Akt controls organismal life-span in invertebrates and cell survival and proliferation in mammals by inhibiting the activity of members of the FOXO family of transcription factors. We show that mammalian FOXO3a also functions at the G2 to M checkpoint in the cell cycle and triggers the repair of damaged DNA. By gene array analysis, FOXO3a was found to modulate the expression of several genes that regulate the cellular response to stress at the G2-M checkpoint. The growth arrest and DNA damage response gene Gadd45a appeared to be a direct target of FOXO3a that mediates part of FOXO3a's effects on DNA repair. These findings indicate that in mammals FOXO3a regulates the resistance of cells to stress by inducing DNA repair and thereby may also affect organismal life-span.

PYRIN-containing Apaf1-like proteins (PYPAFs) are members of the nucleotide-binding site/leucine-rich repeat (NBS/LRR) family of signal transduction proteins. We report here that PYPAF7 is a novel PYPAF protein that activates inflammatory signaling pathways. The expression of PYPAF7 is highly restricted to immune cells, and its gene maps to chromosome 19q13.4, a locus that contains a cluster of genes encoding numerous PYPAF family members. Co-expression of PYPAF7 with ASC results in the recruitment of PYPAF7 to distinct cytoplasmic loci and a potent synergistic activation of NF-B. To identify other proteins involved in PYPAF7 and ASC signaling pathways, we performed a mammalian twohybrid screen and identified pro-caspase-1 as a binding partner of ASC. Co-expression of PYPAF7 and ASC results in the synergistic activation of caspase-1 and a corresponding increase in secretion of interleukin-1␤. In addition, PYPAF1 induces caspase-1-dependent cytokine processing when co-expressed with ASC. These findings indicate that PYPAF family members participate in inflammatory signaling by regulating the activation of NF-B and cytokine processing.

Currently, no approved therapeutics exist to treat or prevent infections induced by Ebola viruses, and recent events have demonstrated an urgent need for rapid discovery of new treatments. Repurposing approved drugs for emerging infections remains a critical resource for potential antiviral therapies. We tested ~2600 approved drugs and molecular probes in an in vitro infection assay using the type species, Zaire ebolavirus. Selective antiviral activity was found for 80 U.S. Food and Drug Administration–approved drugs spanning multiple mechanistic classes, including selective estrogen receptor modulators, antihistamines, calcium channel blockers, and antidepressants. Results using an in vivo murine Ebola virus infection model confirmed the protective ability of several drugs, such as bepridil and sertraline. Viral entry assays indicated that most of these antiviral drugs block a late stage of viral entry. By nature of their approved status, these drugs have the potential to be rapidly advanced to clinical settings and used as therapeutic countermeasures for Ebola virus infections.

PYRIN-containing Apaf-1-like proteins (PYPAFs) are a recently identi¢ed family of proteins thought to function in apoptotic and in£ammatory signaling pathways. PYPAF1 and PYPAF7 proteins have been found to assemble with the PYRIN^CARD protein ASC and coordinate the activation of NF-U UB and pro-caspase-1. To determine if other PYPAF family members function in pro-in£ammatory signaling pathways, we screened ¢ve other PYPAF proteins (PYPAF2, PYPAF3, PY-PAF4, PYPAF5 and PYPAF6) for their ability to activate NF-U UB and pro-caspase-1. Co-expression of PYPAF5 with ASC results in a synergistic activation of NF-U UB and the recruitment of PYPAF5 to punctate structures in the cytoplasm. The expression of PYPAF5 is highly restricted to granulocytes and T-cells, indicating a role for this protein in in£ammatory signaling. In contrast, PYPAF2, PYPAF3, PYPAF4 and PYPAF6 failed to colocalize with ASC and activate NF-U UB. PYPAF5 also synergistically activated caspase-1-dependent cytokine processing when co-expressed with ASC. These ¢ndings suggest that PYPAF5 functions in immune cells to coordinate the transduction of pro-in£ammatory signals to the activation of NF-U UB and pro-caspase-1.

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