title: Distinctive Nuclear Localization Signals in the OomycetePhytophthora sojae.
abstract: To date, nuclear localization signals (NLSs) that target proteins to nuclei in oomycetes have not been defined, but have been assumed to be the same as in higher eukaryotes. Here, we use the soybean pathogenPhytophthora sojaeas a model to investigate these sequences in oomycetes. By establishing a reliablein vivoNLS assay based on confocal microscopy, we found that many canonical monopartite and bipartite classical NLSs (cNLSs) mediated nuclear import poorly inP. sojae. We found that efficient localization ofP. sojaenuclear proteins by cNLSs requires additional basic amino acids at distal sites or collaboration with other NLSs. We found that several representatives of another well-characterized NLS, proline-tyrosine NLS (PY-NLS) also functioned poorly inP. sojae. To characterize PY-NLSs inP. sojae, we experimentally defined the residues required by functional PY-NLSs in threeP. sojaenuclear-localized proteins. These results showed that functionalP. sojaePY-NLSs include an additional cluster of basic residues for efficient nuclear import. Finally, analysis of several highly conservedP. sojaenuclear proteins including ribosomal proteins and core histones revealed that these proteins exhibit a similar but stronger set of sequence requirements for nuclear targeting compared with their orthologs in mammals or yeast.
authors.affiliation: Interdisciplinary Ph.D. Program in Genetics, Bioinformatics and Computational Biology, Virginia TechBlacksburg, VA, USA; Center for Genome Research and Biocomputing and Department of Botany and Plant Pathology, Oregon State UniversityCorvallis, OR, USA.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Environmental and Molecular Toxicology, Oregon State University Corvallis, OR, USA.
authors.forename: Hyo Sang
authors.initials: HS
authors.lastname: Jang
authors.affiliation: Molecular and Cellular Biology Program, Oregon State UniversityCorvallis, OR, USA; Biological and Population Health Sciences, Oregon State UniversityCorvallis, OR, USA.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Watson
authors.affiliation: Center for Genome Research and Biocomputing and Department of Botany and Plant Pathology, Oregon State University Corvallis, OR, USA.
authors.forename: Dulani P
authors.initials: DP
authors.lastname: Wellappili
authors.affiliation: Interdisciplinary Ph.D. Program in Genetics, Bioinformatics and Computational Biology, Virginia TechBlacksburg, VA, USA; Center for Genome Research and Biocomputing and Department of Botany and Plant Pathology, Oregon State UniversityCorvallis, OR, USA.
authors.forename: Brett M
authors.initials: BM
authors.lastname: Tyler
keywords: NLS; PY-NLS; Phytophthora sojae; classical NLS; nuclear localization; nucleus labeling; oomycetes