A number of flavivirus infections may lead to acute lethal haemorrhagic fever or encephalitis in patients and are therefore of great global public health concern. Flaviviruses are enveloped viruses with a single-stranded, non-segmented positive RNA genome [2]. The approximate 11 kb long genome contains only one open reading frame encoding a single polyprotein, which is thereafter cleaved by cellular and viral proteases to form three structural and seven non-structural proteins (NS1, NS2a, NS2b, NS3, NS4a, NS4b, NS5). Recent studies also reported that a NS1′ viral protein, which is often

detected during infection, is the possible result of ribosomal frameshifting [3]. The NS3 protein has a pivotal function in flavivirus RNA replication SCH727965 concentration and viral protein maturation [4, 5]. It consists of two functional domains, protease and helicase in N-and C-terminus, respectively. NS5 protein is constituted by two distinct Pictilisib cost domains as well, namely an N-terminal MLN8237 cell line methyltransferase and

a C-terminal RNA-dependent RNA polymerase that are required for capping and synthesis of the viral RNA genome, respectively [6]. NS3 and NS5 proteins are the major enzymatic components of the viral replication complex, which promotes efficient viral replication in close association with cellular host factors [7]. Due to their numerous functions and their central role in the Thymidylate synthase virus life cycle, NS3 and NS5 have been designated as important drug targets [8, 9]. To identify host factors interacting with flavivirus NS3 and NS5 proteins, we have conducted a high-throughput yeast two-hybrid (Y2H) screen. Since the pioneer study published by Uetz et al. in 2006 on Herpes viruses interactome, the use of the high-throughput yeast two-hybrid (Y2H) technique to conduct genome-scale screens of virus-host protein interactions has led to major advances in our understanding of viral infections [10–13]. These results from the integrative system biology approaches highlighted the ability of viral proteins to interfere with intracellular pathways

to the benefit of viral replication. Indeed, viruses not only take advantage of such interactions for their replication or to escape host defense but also induce cellular interactome perturbations leading eventually to infection-related diseases. Recently, studies using genome-wide RNA interference screens in human or insect cells were able to provide the identification of numerous host cell factors potentially required to interfere with DENV or WNV infection [14]. Some of the targets identified are host (mammalian) or vector (insect) exclusive, others are common to both. This suggests that conservation of required factors between dipteran and human hosts is associated to flavivirus propagation [15].