Role of Cellular Casein Kinase II in the Function of the Phosphoprotein (P) Subunit of RNA Polymerase of Vesicular Stomatitis Virus

• DOI: 10.1074/jbc.270.41.24100
• Publication Date: 2002-07-26T15:15:23Z
• Authors: Tapas Das; Ashim K. Gupta; Paul W. Sims; Craig A. Gelfand; Joyce E. Jentoft; Amiya K. Banerjee
• Keywords: Phosphoprotein; Casein kinase 2

The phosphorylation of the P protein vesicular stomatitis virus by cellular casein kinase II (CKII) is essential for its activity in viral transcription. Recent vitro studies have demonstrated that CKII converts inactive unphosphorylated form (P0) to an active phosphorylated P1, after at two serine residues, Ser-59 and Ser-61. To gain insight into role CKII-mediated structure function protein, we carried out circular dichroism (CD) biochemical analyses both P0 P1. results CD reveal P1 significantly increases predicted α-helical from 27 48%. defective double mutant (P59/61), which transcriptionally inactive, possesses a secondary similar P0. concentration 50 μg/ml, elutes gel filtration column apparently as dimer, whereas elute monomer same concentration. Interestingly, unlike wild-type mutants either or Ser-61 altered alanine required high optimal phosphorylation. We demonstrate here necessary sufficient transactivate L polymerase although alteration one residue decreases affinity CKII. also shown binds N-RNA template more efficiently than formation prerequisite subsequent protein-associated kinase. In addition, P59/61 acts transdominant negative when used transcription reconstitution assay presence protein.