Unique motif for nucleolar retention and nuclear export regulated by phosphorylation.
By microinjecting purified glutathione S-transferase linked to all or parts of herpes simplex virus type 1 US11 protein into either the nucleus or the cytoplasm, we have demonstrated that this nucleolar protein exhibits a new type of localization signal controlling both retention in nucleoli and export to the cytoplasm. Saturated mutagenesis combined with computer modeling allowed us to draw the fine-structure map of this domain, revealing a new proline-rich motif harboring both activities, which are temperature dependent and regulated by phosphorylation. Finally, crossing the nuclear pore complex from the cytoplasm to the nucleus is an energy-dependent process for US11 protein, while getting to nucleoli through the nucleoplasm is energy independent.
Catez
Frédéric
F
INSERM U369, Faculté de Médecine Lyon-René Théophile Hyacinthe Laennec, 69372 Lyon Cedex 08, France.
Erard
Monique
M
Schaerer-Uthurralt
Nathalie
N
Kindbeiter
Karine
K
Madjar
Jean-Jacques
JJ
Diaz
Jean-Jacques
JJ
D021581:Active Transport, Cell Nucleus / Q000502:physiology*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002466:Cell Nucleolus / Q000378:metabolism*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008845:Microinjections; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010766:Phosphorylation; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012710:Serum Albumin, Bovine / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D021382:Protein Sorting Signals; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C074546:US11 protein, herpesvirus; D014764:Viral Proteins; D012710:Serum Albumin, Bovine; D005982:Glutathione Transferase