Functionally distinct monomers and trimers produced by a viral oncoprotein


While the process of homo-oligomer formation and disassembly into subunits represents a common strategy to regulate protein activity, reports of proteins in which the subunit and homo-oligomer perform independent functions are scarce. Tumorigenesis induced by the adenovirus E4-ORF1 oncoprotein depends on its binding to a select group of cellular PDZ proteins, including MUPP1, MAGI-1, ZO-2 and Dlg1. We report here that in cells E4-ORF1 exists as both a monomer and trimer and that monomers specifically bind and sequester MUPP1, MAGI-1 and ZO-2 within insoluble complexes whereas trimers specifically bind Dlg1 and promote its translocation to the plasma membrane. This work exposes a novel strategy wherein the oligomerization state of a protein not only determines the capacity to bind separate related targets but also couples the interactions to different functional consequences.



adenovirus, E4-ORF1, monomer, PDZ, trimer


Copyright 2008 Oncogene. This is a post-print version of a published paper that is available at: Recommended citation: Chung, S. H., R. S. Weiss, K. K. Frese, B. V. Prasad, and R. T. Javier. "Functionally distinct monomers and trimers produced by a viral oncoprotein." Oncogene 27, no. 10 (2008): 1412. DOI: 10.1038/sj.onc.1210784. This item has been deposited in accordance with publisher copyright and licensing terms and with the author's permission.