Nuclear localization of the Epstein-Barr virus EBNA3B protein.
The Epstein-Barr virus nuclear antigen (EBNA) 3B is a hydrophilic, proline-rich, charged protein that is thought to be involved in transcriptional regulation and is targeted exclusively to the cell nucleus, where it localizes to discrete subnuclear granules. Co-localization studies utilizing a fusion protein between enhanced green fluorescent protein (EGFP) and EBNA3B with FLAG-tagged EBNA3A and EBNA3C proteins demonstrated that EBNA3B co-localized with both EBNA3A and EBNA3C in the nuclei of cells when overexpressed. Computer analyses identified four potential nuclear-localization signals (NLSs) in the EBNA3B amino acid sequence. By utilizing fusion proteins with EGFP, deletion constructs of EBNA3B and site-directed mutagenesis, three of the four NLSs (aa 160-166, 430-434 and 867-873) were shown to be functional in truncated forms of EBNA3B, whilst an additional NLS (aa 243-246) was identified within the N-terminal region of EBNA3B. Only two of the NLSs were found to be functional in the context of the full-length EBNA3B protein.
Burgess
Anita
A
Queensland Institute of Medical Research, 300 Herston Road, Brisbane, Queensland 4029, Australia.
Buck
Marion
M
Queensland Institute of Medical Research, 300 Herston Road, Brisbane, Queensland 4029, Australia.
Krauer
Kenia
K
Queensland Institute of Medical Research, 300 Herston Road, Brisbane, Queensland 4029, Australia.
Sculley
Tom
T
Griffith Medical Research Centre, 300 Herston Road, Brisbane, Queensland 4029, Australia.|Queensland Institute of Medical Research, 300 Herston Road, Brisbane, Queensland 4029, Australia.
D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D019309:Epstein-Barr Virus Nuclear Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016297:Mutagenesis, Site-Directed; D019913:Nuclear Localization Signals / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion
D019309:Epstein-Barr Virus Nuclear Antigens; D019913:Nuclear Localization Signals; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins