NAP1L1 and NAP1L4 Binding to Hypervariable Domain of Chikungunya Virus nsP3 Protein Is Bivalent and Requires Phosphorylation
Francisco Domínguez, Nikita Shiliaev, Tetyana Lukash, Peter Agback, Oksana Palchevska, Joseph R. Gould, Chetan D. Meshram, Peter E. Prevelige, Todd J. Green, Tatiana Agback, Elena I. Frolova, Ilya Frolov
Abstract
Cellular proteins play critical roles in the assembly of alphavirus replication complexes (vRCs). Their recruitment is determined by the viral nonstructural protein 3 (nsP3). This protein contains a long, disordered hypervariable domain (HVD), which encodes virus-specific combinations of short linear motifs interacting with host factors during vRC assembly. Our study defined the binding mechanism of NAP1 family members to CHIKV HVD and demonstrated a stimulatory effect of this interaction on viral replication. We show that interaction with NAP1L1 is mediated by two HVD motifs and requires phosphorylation of HVD by CK2 kinase. Based on the accumulated data, we present a map of the binding motifs of the critical host factors currently known to interact with CHIKV HVD. It can be used to manipulate cell specificity of viral replication and pathogenesis, and to develop a new generation of vaccine candidates.