Identification of a cytoplasmic interaction partner of the large regulatory proteins Rep78/Rep68 of adeno-associated virus type 2 (AAV-2).
Through yeast two-hybrid analysis and coimmunoprecipitation studies, we have identified a novel cellular AAV-2 Rep78/Rep68 interaction partner located predominantly in the cytoplasm. In public databases, it has been assigned as KCTD5, because of a region of high similarity to the cytoplasmic tetramerization domain of voltage-gated potassium channels. Whereas Rep/KCTD5 interaction relied on the region surrounding the Rep nuclear localization signal, nuclear accumulation of Rep was not required. Wildtype Rep78/Rep68 proteins induced the translocation of large portions of KCTD5 into the nucleus pointing to functional interactions both in the cytoplasm and the nucleus. In line with an anticipated functional interference in the cytoplasm, KCTD5 overexpression completely abrogated Rep68-mediated posttranscriptional activation of a HIV-LTR driven luciferase reporter gene. Our study expands the panel of already identified nuclear Rep interaction partners to a cytoplasmic protein, which raises the awareness that important steps in the AAV life cycle may be regulated in this compartment.
Weger
Stefan
S
Institut für Virologie, Charité Campus Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 27, 12203 Berlin, Germany. stefan.weger@charite.de
Hammer
Eva
E
Götz
Anne
A
Heilbronn
Regine
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D000229:Dependovirus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D021381:Protein Transport; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C521187:KCTD5 protein, human; D015221:Potassium Channels; D014764:Viral Proteins; C068734:rep proteins, Adeno-associated virus 2