Protein arginine methylation during lytic adenovirus infection

Arginine methylation of proteins affects major processes in the cell, including transcriptional regulation, mRNA metabolism, signal transduction and protein sorting. Arginine methylation of Ad (adenovirus) E1B 55-kDa-associated protein E1B-AP5 was recently described by us [Kzhyshkowska, Schutt, Liss, Kremmer, Stauber, Wolf and Dobner (2001) Biochem. J. 358, 305-314]. In this first example of protein arginine methylation analysis in Ad-infected cells, we investigated methylation of the E1B-AP5 and the viral L4-100 kDa protein. We demonstrate that E1B-AP5 methylation is enhanced during the course of infection in a cell-type-specific manner. We also show that L4-100 kDa is efficiently methylated in Ad-infected cells. L4-100 kDa formed complex with methyltransferase in vivo during productive infection, and can be methylated by HRMT1L2 (human protein arginine methyltransferase 1) in vitro. Comparative analysis of E1B-AP5 and L4-100 kDa protein methylation in Ad-infected HeLa, MCF-7 and H1299 cells revealed that the profile of protein arginine methylation correlates with the efficiency of Ad proteins production. Our results suggest that protein arginine methylation is an important host-cell function required for efficient Ad replication.