Serine-173 of the Epstein-Barr virus ZEBRA protein is required for DNA binding and is a target for casein kinase II phosphorylation.
An Epstein-Barr virus-encoded protein, ZEBRA, mediates the switch from latency to the viral lytic life cycle. ZEBRA's domain structure and DNA binding specificity resemble that of cellular transcriptional activators such as c-Fos/c-Jun. We show that ZEBRA, like c-Jun, is phosphorylated by casein kinase II (CKII). The principal site of phosphorylation is serine-173 (S173), five amino acids upstream of the basic DNA recognition domain. CKII phosphorylation abrogated ZEBRA's capacity to bind its target DNA sequences. S173 is a functional component of ZEBRA's DNA binding domain, since mutation of S173 to alanine (S173A) reduced DNA binding in vitro to 10% of wild-type levels. Transcriptional activation of a native viral promoter in vivo by mutant S173A was also reduced markedly. Reversible phosphorylation of S173 is likely to be an important means of regulating ZEBRA's activity in vivo.
Kolman
J L
JL
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510.
Taylor
N
N
Marshak
D R
DR
Miller
G
G
D000409:Alanine; D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D047390:Casein Kinase II; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012694:Serine; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014764:Viral Proteins / Q000378:metabolism*
C063676:BZLF1 protein, Herpesvirus 4, Human; D017931:DNA Primers; D004268:DNA-Binding Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014764:Viral Proteins; D012694:Serine; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D000409:Alanine