Bioinformatical analysis of nuclear localisation sequences in penaeid densoviruses

Nuclear location sequences (NLSs) link proteins to importation molecules for transportation into the nucleus. A bioinformatical search of the penaeid parvoviruses was undertaken to look for NLS. All three ORFs of Penaeus merguiensis densovirus (PmergDNV) have functional NLS whilst only the two non-structural proteins of Penaeus stylirostris densovirus (PstDNV) appear to. In PmergDNV, NS1 has a NLS similar to DNA helicase Q1, NS2 is similar to Dorsal and VP1 is similar to SV40 T-antigen signal. In PstDNV, NS2 has a NLS that is an unrecognised pattern unless it is a monopartite Chelsky signal whilst NS1 has both a Dorsal and minute virus of mouse signals. The capsid protein NIS of PstDNV is likely to be inefficient. Spawner isolated mortality virus has a NLS like DNA helicase Q1.These NLSs affect the nature of inclusion bodies seen with light microscopy, basophilic in PmergDNV: eosinophilic in PstDNV and the site of encapsidation, nuclear in PmergDNV; cytoplasmic in PstDNV as seen with TEM. Many possible NISs in penaeid parvoviruses are homologues to those in eukaryotic organisms and need to be tested experimentally. (C) 2013 Elsevier B.V. All rights reserved.