Abstract
Chikungunya virus (CHIKV) is a mosquito-borne virus, which has created an alarming threat in the world due to unavailability of vaccine and antiviral compounds. The CHIKV nsP2 contains ATPase, RTPase, helicase and protease activities, whereas, nsP1 is a viral capping enzyme. In alphaviruses, the four non-structural proteins form the replication complex in the cytoplasm and this study characterizes the interaction between CHIKV nsP1 and nsP2. It was observed that, both the proteins co-localize in the cytoplasm and interact in the CHIKV infected cells by confocal microscopy and immunoprecipitation assay. Further, it was demonstrated through mutational analysis that, the amino acids 1-95 of nsP2 and 170-288 of nsP1 are responsible for their direct interaction. Additionally, it was noticed that, the ATPase activity of nsP2 is enhanced in the presence of nsP1, indicating the functional significance of this interaction. In silico analysis showed close (≤1.7 Å) polar interaction (hydrogen bond) between Glu4, Arg7, 96, 225 of nsP2 with Lys256, 206, Val367 and Phe312 of nsP1 respectively. Hence, this investigation provides molecular characterization of CHIKV nsP1-nsP2 interaction which might be a useful target for rational designing of antiviral drugs.
Highlights
In the year 1955, Marion Robinson and W.H.R
Chikungunya virus (CHIKV) is closely related to Semliki Forest virus (SFV) and Sindbis virus, most of the functions of nonstructural proteins (nsPs) were predicted in comparison to these alphaviruses[11]
The CHIKV nsP2 or nsP1 protein was immunoprecipitated from infected Vero cell lysates using the anti-nsP2 monoclonal antibody or anti-nsP1 polyclonal antibody respectively
Summary
In the year 1955, Marion Robinson and W.H.R. Lumsden described a viral outbreak in 1952 on the Makonde Plateau and Tanganyika region, which they named as Chikungunya fever (CHIKF)[1,2]. The genome is around 11.8 kb long and encodes four nonstructural proteins (nsPs) (nsP1, nsP2, nsP3 and nsP4) which help in the synthesis of the viral RNA. According to the various computational analysis of homologous structural and functional prediction, three domains have been described for nsP113. These are the N-terminus (NT) methyltransferase (MT) and guanylyltransferase domain (1-170 aa), the middle membrane binding (MB) domain (171-300 aa) and the C-terminus (CT) D3 domain (301-535 aa)[13]. During the late phase of replication, nsP2 cleaves and processes all the mature nsPs, which form the late RC to synthesize the positive sense 46S genomic and 26S subgenomic RNA (the precursor RNA for structural proteins)[30,31]. It has been shown that the alphavirus nsP3 and nsP4 with nsP1 helps in the synthesis of minus-strand RNA genome in RC31,35
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
