The Nuclear Pore Complex: A Target for NS3 Protease of Dengue and Zika Viruses

Abstract

During flavivirus infection, some viral proteins move to the nucleus and cellular components are relocated from the nucleus to the cytoplasm. Thus, the integrity of the main regulator of the nuclear-cytoplasmic transport, the nuclear pore complex (NPC), was evaluated during infection with dengue virus (DENV) and Zika virus (ZIKV). We found that while during DENV infection the integrity and distribution of at least three nucleoporins (Nup), Nup153, Nup98, and Nup62 were altered, during ZIKV infection, the integrity of TPR, Nup153, and Nup98 were modified. In this work, several lines of evidence indicate that the viral serine protease NS2B3 is involved in Nups cleavage. First, the serine protease inhibitors, TLCK and Leupeptin, prevented Nup98 and Nup62 cleavage. Second, the transfection of DENV and ZIKV NS2B3 protease was sufficient to inhibit the nuclear ring recognition detected in mock-infected cells with the Mab414 antibody. Third, the mutant but not the active (WT) protease was unable to cleave Nups in transfected cells. Thus, here we describe for the first time that the NS3 protein from flavivirus plays novel functions hijacking the nuclear pore complex, the main controller of the nuclear-cytoplasmic transport.

The antiviral effect of metformin on zika and dengue virus infection

“…The YFV 17D (live-attenuated vaccine) propagation was carried out in C6/36 Aedes albopictus cells adapted to grow at 35 °C 54 . The DENV and ZIKV titers were determined by foci forming units (FFU) assay in Huh-7 cells 55 , while YFV titers by plaque-forming units (PFU) assays 56 . The CD1 suckling mice brains from mock-infected mice or complete medium for C6/36 cells were used as control.…”

“…Supernatants from the DENV and the ZIKV infected untreated, and treated cells were used to determine the viral yield using foci forming units (FFU) assay, following the methodology previously reported by De Jesús-González et al 55 . Supernatants from YFV-infected untreated and treated cells were used to determine the viral yield using plaque-forming units (PFU) modified assay of Morens et al 56 .…”

Zika virus NS3 protease and its cellular substrates

“…In the case of ZIKV, some protease targets have been identified, and these are listed in Table 1. Western blots and the fluorescence microscopy analysis (43) In the present work, we reviewed the published data and verified these potential protease targets experimentally by measuring changes in the levels of potential cellular targets in the presence of active or inactive protease. Since in some cases the localization or specificity of the protease may differ in the absence of other viral proteins, we also measured the levels of potential NS3 targets in ZIKV-infected cells.…”

The Role of Protein Disorder in Nuclear Transport and in Its Subversion by Viruses

“…The ZIKV and DENV serine-protease complex NS23B is responsible for degrading and altering the distribution of multiple FG-Nups following DENV and ZIKV infection. While both viruses target Nup98 and Nup153, an inner ring Nup and nuclear basket Nup, respectively ( Figure 2 ), the degradation of the translocated promoter region (TPR) protein (scaffolding element of the NPC) and the channel FG-Nup Nup62 ( Figure 2 ) were specific to ZIKV and DENV, respectively [ 104 ]. Although the degraded Nups are known to play roles in nuclear protein transport and mRNA export, further studies are required to determine how this strategy favours DENV and ZIKV replication.…”