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Constitutive activation of the canonical NF-B signaling pathway is a major factor in Kaposi’s Sarcoma Herpes virus (KSHV) pathogenesis where it is essential for the survival of primary effusion lymphoma (PEL). Central to this process is persistent upregulation of the inhibitor of B kinase (IKK) kinase complex by the virally encoded oncoprotein vFLIP. Although the physical interaction between vFLIP and the IKK kinase regulatory component essential for persistent activation, IKK, has been well characterized, it remains unclear how the kinase subunits are rendered active mechanistically. Using a combination of cell-based assays, biophysical techniques, and structural biology, we demonstrate here that vFLIP alone is sufficient to activate the IKK kinase complex. Furthermore, we identify weakly stabilised, high molecular weight vFLIP-IKK assemblies that are key to the activation process. Taken together, our results are the first to reveal that vFLIP induced NF-B activation pivots on the formation of structurally specific vFLIP-IKK multimers which have an important role in rendering the kinase subunits active through a process of autophosphorylation. This mechanism of NF-B activation is in contrast to those utilised by endogenous cytokines and cellular FLIP homologues.

Alzheimer’s disease (AD), the most prevalent form of dementia, is a progressive and devastating neurodegenerative condition for which there are no effective treatments. Understanding the molecular pathology of AD during disease progression may identify new ways to reduce neuronal damage. Here, we present a longitudinal study tracking dynamic proteomic alterations in the brains of an inducible Drosophila melanogaster model of AD expressing the Arctic mutant Aβ42 gene. We identified 3093 proteins from flies that were induced to express Aβ42 and age-matched healthy controls using label-free quantitative ion-mobility data independent analysis mass spectrometry. Of these, 228 proteins were significantly altered by Aβ42 accumulation and were enriched for AD-associated processes. Network analyses further revealed that these proteins have distinct hub and bottleneck properties in the brain protein interaction network, suggesting that several may have significant effects on brain function. Our unbiased analysis provides useful insights into the key processes governing the progression of amyloid toxicity and forms a basis for further functional analyses in model organisms and translation to mammalian systems.