PMID: 23747198

Authors:

Sami Saribas A, Abou-Gharbia M, Childers W, Sariyer IK, White MK, Safak M

Title:

Essential roles of Leu/Ile/Phe-rich domain of JC virus agnoprotein in dimer/oligomer formation, protein stability and splicing of viral transcripts.

Journal:

Virology. 2013 Aug 15;443(1):161-76. doi: 10.1016/j.virol.2013.05.003. Epub 2013 , Jun 6.

Abstract:

Agnoprotein is one of the key regulatory proteins of polyomaviruses, including JCV, BKV and SV40 and is required for a productive viral life cycle. We have recently reported that agnoprotein forms stable dimer/oligomers mediated by a predicted amphipathic alpha-helix, spanning amino acids (aa), 17 to 42. Deletion of the alpha-helix renders a replication incompetent virus. Here, we have further characterized this region by a systematic deletion and substitution mutagenesis and demonstrated that a Leu/Ile/Phe-rich domain, (spanning aa 28-39) within alpha-helix is indispensable for agnoprotein structure and function. Deletion of aa 30-37 severely affects the dimer/oligomer formation and stable expression of the protein. Mutagenesis data also indicate that the residues, 34-36, may be involved in regulation of the splicing events of JCV transcripts. Collectively, these data suggest that the Leu/Ile/Phe-rich domain plays critical roles in agnoprotein function and thus represents a potential target for developing novel therapeutics against JCV infections.