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.