Kaposi's sarcoma-associated herpesvirus (human herpesvirus-8) open reading frame 36 protein is a serine protein kinase

Junsoo Park, Daeyoup Lee, Taegun Seo, Jongkyeong Chung, Joonho Choe

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Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus that is implicated in the pathogenesis of Kaposi's sarcoma. The nucleotide sequence of the KSHV open reading frame (ORF) 36 predicts a polypeptide with significant sequence homology to known protein kinases. In this paper, we show that KSHV ORF36 mRNA is expressed during lytic growth and that ORF36 protein is localized in the nucleus. To determine whether the KSHV ORF36 protein is a protein kinase, we expressed it as a glutathione S-transferase (GST) fusion protein (GST-ORF36). Affinity-purified preparations of the GST-ORF36 fusion protein revealed that the protein is autophosphorylated. Mutation of lysine-108 to glutamine dramatically decreased the protein kinase activity of the purified protein, supporting the hypothesis that the protein kinase activity is inherent to the ORF36 protein. Phosphoamino acid analysis showed that the KSHV ORF36 fusion protein is phosphorylated on a serine residue, implying that KSHV ORF36 encodes a serine protein kinase.

Original languageEnglish
Pages (from-to)1067-1071
Number of pages5
JournalJournal of General Virology
Issue number4
Publication statusPublished - 2000 Jan 1


All Science Journal Classification (ASJC) codes

  • Virology

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