Cocksfoot mottle sobemovirus coat protein contains two nuclear localization signals |
| |
Authors: | Allan Olspert Heiti Paves Raavo Toomela Tiina Tamm Erkki Truve |
| |
Institution: | (1) Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia;(2) Present address: Department of General and Microbial Biochemistry, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; |
| |
Abstract: | Cocksfoot mottle virus (CfMV) coat protein (CP) localization was studied in plant and mammalian cells. Fusion of the full-length CP with enhanced
green fluorescent protein (EGFP) localized to the cell nucleus whereas similar constructs lacking the first 33 N-terminal
amino acids of CP localized to the cytoplasm. CP and EGFP fusions containing mutations in the arginine-rich motif of CP localized
to the cytoplasm and to the nucleus in plant cells indicating the involvement of the motif in nuclear localization. In mammalian
cells, mutations in the arginine-rich region were sufficient to completely abolish nuclear transport. The analysis of deletions
of amino acid residues 1–11, 1–22, and 22–33 of CP demonstrated that there were two separate nuclear localization signals
(NLS) within the N-terminus—a strong NLS1 in the arginine-rich region (residues 22–33) and a weaker NLS2 within residues 1–22.
Analysis of point mutants revealed that the basic amino acid residues in the region of the two NLSs were individually not
sufficient to direct CP to the nucleus. Additional microinjection studies with fluorescently labeled RNA and CP purified from
CfMV particles demonstrated that the wild-type CP was capable of transporting the RNA to the nucleus. This feature was not
sequence-specific in transient assays since both CfMV and GFP mRNA were transported to the cell nucleus by CfMV CP. Together
the results suggest that the nucleus may be involved in CfMV infection. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|