| Abstrakt: |
ABSTRACTNuclear filamentous actin (F-actin) is required for nucleopolyhedrovirus (NPV) progeny production in NPV-infected, cultured lepidopteran cells. We have determined that monomeric G-actin is localized within the nuclei of host cells during the early stage of infection by Autographa californicamulticapsid nucleopolyhedrovirus (AcMNPV). With a library of cloned AcMNPV genomic fragments, along with a plasmid engineered to express enhanced green fluorescent protein-Bombyx moriG-actin in transient transfection experiments, we identified six AcMNPV early genes that mediate nuclear localization of G-actin in TN-368 cells: ie-1, pe38, he65, Ac004, Ac102,and Ac152. Within this subset, ie-1and pe38encode immediate-early transcriptional transactivators, he65encodes a delayed-early product, and the products encoded by Ac004, Ac102,and Ac152have not been characterized. We found that when driven by foreign promoters, ie-1, pe38,and Ac004had to be expressed prior to Ac102or he65for nuclear G-actin to accumulate and that expression of Ac152was no longer required. These results and others suggested that the product of Ac152was a transactivator (directly or indirectly) of both Ac102and he65and that recruitment of G-actin to the nucleus was a temporally regulated process. Determining the functions of each of the six AcMNPV gene products with respect to our assay should provide valuable clues to basic cellular mechanisms of actin regulation and how AcMNPV infection affects them. |
