Generation and characterization of a monoclonal antibody against importin α7/NPI-2

Intracellular distribution of pseudorabies virus UL2 and detection of its nuclear import mechanism

Pseudorabies virus (PRV) UL2 (pUL2) is a multifunctional protein, which is homologous with herpes simplex virus 1 early protein UL2 (hUL2) and crucial for the viral propagation. Yet, how pUL2 executes its roles in the viral life cycle remain inadequately understood. In order to uncover its effect on the procedure of PRV infection, investigation was performed to examine the subcellular distribution of pUL2 and establish its trafficking mechanism. In the present study, enhanced yellow fluorescent protein or Myc tag fused pUL2 was transiently overexpressed in transfected cells and exhibited an absolutely nuclear accumulation without the existence of other PRV proteins. Additionally, the nuclear trafficking of pUL2 was proved to rely on Ran-, transportin-1, importin β1, importin α1, α3 and α5. Accordingly, these data will benefit the knowledge of pUL2-mediated biological effects in PRV infection cycle.

Effects of polyacrylamide molecular weight and mass concentration on water transport characteristics of iron tailings

Iron tailings have few macropores which severely inhibit infiltration and transport of soil water. Polyacrylamide (PAM) can regulate soil water, but it is rarely used when remediating tailings matrix. In this research, PAM of four molecular weights of 300w, 600w, 800w, and 1000w were selected as amendments, and were each applied at five mass concentrations of 0% (CK), 0.01%, 0.04%, 0.08%, and 0.16% to observe their effects on water transport in iron tailings using column simulations in the laboratory. After adding PAM, the water retention and saturated water content of iron tailings increased significantly (P < 0.05). With increases in PAM molecular weight and mass concentration, the saturated hydraulic conductivity showed a downward trend, but the saturated hydraulic conductivity increased after a dry-wet cycle. With the increase of PAM mass concentration, adding PAM of 1000w molecular weight to iron tailing decreased infiltration capacity, but treatments of other molecular weights all initially increased then decreased infiltration capacity. The greatest improvement on infiltration capacity of iron tailings was observed with the addition of PAM of 300w molecular weight and 0.01% mass concentration. Adding PAM increased the vertical depth of the saturation zone of iron tailings (P < 0.05) with a maximum depth of 20.83 cm. The Kostiakov model more accurately simulated water infiltration of iron tailings compared with the Horton and Philip models. On the whole, when PAM of low molecular weight and concentration was added to iron tailings, PAM increased stable infiltration, saturated water content, and water retention. It also inhibited saturated hydraulic conductivity of iron tailings. Therefore, in practice, it is necessary to select the appropriate molecular weight and mass concentration of PAM according to the dominant limiting factors and remediation needs of the matrix.

Molecular anatomy of the subcellular localization and nuclear import mechanism of herpes simplex virus 1 UL6

As an indispensable structure protein, the herpes simplex virus 1 (HSV-1) UL6 has been described to exert numerous roles in viral proliferation. However, its exact subcellular localization and subcellular transport mechanism is not well known. In the present study, by utilizing confocal fluorescent microscopy, UL6 was shown to mainly locate in the nucleus in enhanced yellow fluorescent protein or Flag tag fused expression plasmid-transfected cells or HSV-1-infected cells, whereas its predicted nuclear localization signal was nonfunctional. In addition, by exploiting dominant negative mutant and inhibitor of different nuclear import receptors, as well as co-immunoprecipitation and RNA interference assays, UL6 was established to interact with importin α1, importin α7 and transportin-1 to mediate its nuclear translocation under the help of Ran-mediated GTP hydrolysis. Accordingly, these results will advance the knowledge of UL6-mediated biological significances in HSV-1 infection cycle.

Identification of the molecular determinants for nuclear import of PRV EP0

Pseudorabies virus (PRV) early protein EP0 is a homologue of the herpes simplex virus 1 (HSV-1) immediate-early protein ICP0, which is a multifunctional protein and important for HSV-1 infection. However, the definite function of EP0 during PRV infection is not clear. In this study, to determine if EP0 might localize to the nucleus, as it is shown for its homologue in HSV-1, the subcellular localization pattern and molecular determinants for the nuclear import of EP0 were investigated. EP0 was demonstrated to predominantly target the nucleus in both PRV infected- and plasmid-transfected cells. Furthermore, the nuclear import of EP0 was shown to be dependent on the Ran-, importin α1-, α3-, α7-, β1- and transportin-1-mediated multiple pathways. Taken together, these data will open up new horizons for portraying the biological roles of EP0 in the course of PRV lytic cycle.

Characterization of the subcellular localization and nuclear import molecular mechanisms of herpes simplex virus 1 UL2

As a crucial protein, the herpes simplex virus 1 (HSV-1) UL2 protein has been shown to take part in various stages of viral infection, nonetheless, its exact subcellular localization and transport molecular determinants are not well known thus far. In the present study, by using live cells fluorescent microscopy assay, UL2 tagged with enhanced yellow fluorescent protein was transiently expressed in live cells and showed a completely nuclear accumulation without the presence of other HSV-1 proteins. Moreover, the nuclear transport of UL2 was characterized to be assisted by multiple transport pathways through Ran-, importin α1-, α5-, α7-, β1- and transportin-1 cellular transport receptors. Consequently, these results will improve understanding of UL2-mediated biological functions in HSV-1 infection cycles.

Probing the nuclear import signal and nuclear transport molecular determinants of PRV ICP22

BACKGROUND

Herpes simplex virus 1 (HSV-1) ICP22 is a multifunctional protein and important for HSV-1 replication. Pseudorabies virus (PRV) ICP22 (P-ICP22) is a homologue of HSV-1 ICP22 and is reported to be able to selectively modify the transcription of different kinetic classes of PRV genes, however, the subcellular localization, localization signal and molecular determinants for its transport to execute this function is less well understood.

RESULTS

In this study, by utilizing live cells fluorescent microscopy, P-ICP22 fused to enhanced yellow fluorescent protein (EYFP) gene was transient expressed in live cells and shown to exhibit a predominantly nucleus localization in the absence of other viral proteins. By transfection of a series of P-ICP22 deletion mutants fused to EYFP, a bona fide nuclear localization signal (NLS) and its key amino acids (aa) of P-ICP22 was, for the first time, determined and mapped to aa 41-60 (PASTPTPPKRGRYVVEHPEY) and aa 49-50 (KR), respectively. Besides, the P-ICP22 was demonstrated to be targeted to the nucleus via Ran-, importin α1-, and α7-mediated pathway.

CONCLUSIONS

Our findings reported herein disclose the NLS and molecular mechanism for nuclear transport of P-ICP22, these results will uncover new avenues for depicting the biological roles of P-ICP22 during PRV infection.

Identification of molecular determinants for the nuclear import of pseudorabies virus UL31

Herpes simplex virus 1 (HSV-1) UL31 is a multifunctional protein and important for HSV-1 infection. Pseudorabies virus (PRV) UL31 is a late protein homologous to HSV-1 UL31. Previous studies showed that PRV UL31 is predominantly localized to nucleus, however, the molecular determinants for its nuclear import were unclear to date. Here, by utilizing live cells fluorescent microscopy, UL31 fused with enhanced yellow fluorescent protein was transiently expressed in live cells and confirmed to exclusively target to the nucleus in the absence of other viral proteins. Furthermore, the nuclear import of UL31 was found to be dependent on the Ran-, importin α1-, α3-, α5-, α7-, β1-and transportin-1-mediated pathway. Therefore, these results would open up new avenues for depicting the biological functions of UL31 during PRV infection.