Molecular basis for the interaction between rabies virus phosphoprotein P and the dynein light chain LC8: dissociation of dynein-binding properties and transcriptional functionality of P

Laboratoire de Génétique des Virus, CNRS, 91198 Gif sur Yvette, France 1 Laboratoire des Lyssavirus, Institut Pasteur 25 rue du Dr Roux, 75724 Paris Cedex 15, France 2 Department of Biochemistry, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, Connecticut 06030-3305, USA 3 Author for correspondence: Danielle Blondel. Fax +33 1 69 82 43 08. e-mail Danielle.Blondel{at}gv.cnrs-gif.fr The lyssavirus phosphoprotein P is a co-factor of the viral RNA polymerase and plays a central role in virus transcription and replication. It has been shown previously that P interacts with the dynein light chain LC8, which is involved in minus end-directed movement of organelles along microtubules. Co-immunoprecipitation experiments and the two-hybrid system were used to map the LC8-binding site to the sequence 139 RSSEDKSTQTTGR 151 . Site-directed mutagenesis of residues D 143 and Q 147 to an A residue abolished binding to LC8. The P–LC8 association is not required for virus transcription, since the double mutant was not affected in its transcription ability in a minigenome assay. Based on the crystal structure of LC8 bound to a peptide from neuronal nitric oxide synthase, a model for the complex between the peptide spanning residues 140–150 of P and LC8 is proposed. This model suggests that P binds LC8 in a manner similar to other LC8 cellular partners.