Blackwell, JL; Brinton, MA. Translation elongation factor-1 alpha interacts with the 3' stem-loop region of West Nile virus genomic RNA. Journal of Virology. 1997 Sep; 71(9): 6433-44. ISSN: 0022-538X.

NAL Call No.: QR360.J6

Descriptors: 3’-terminal stem-loop, flavivirus replication, purification of cellular protein, EF-1 alpha and WNV 3' SL RNA, stoichiometry, RNase footprinting, nitrocellulose filter binding assays.

Abstract: The conserved 3'-terminal stem-loop (3' SL) of the West Nile virus (WNV) genomic RNA was previously used to probe for cellular proteins that may be involved in flavivirus replication and three cellular proteins were detected that specifically interact with the WNV 3' SL RNA (J. L. Blackwell and M. A. Brinton, J. Virol. 69:5650-5658, 1995). In this study, one of these cellular proteins was purified to apparent homogeneity by ammonium sulfate precipitation and liquid chromatography. Amino acid sequence Western blotting, and supershift analyses identified the cellular protein as translation elongation factor-1 alpha (EF-1 alpha). Competition gel mobility shift assays demonstrated that the interaction between EF-1 alpha and WNV 3' SL RNA was specific. Dephosphorylation of EF-1 alpha by calf intestinal alkaline phosphatase inhibited its binding to WNV 3' SL RNA. The apparent equilibrium dissociation constant for the interaction between EF-1 alpha and WNV 3' SL RNA was calculated to be 1.1 x 10(-9) M. Calculation of the stoichiometry of the interaction indicated that one molecule of EF-1 alpha binds to each molecule of WNV 3' SL RNA. Using RNase footprinting and nitrocellulose filter binding assays, we detected a high-activity binding site on the main stem of the WNV 3' SL RNA. Interaction with EF-1 alpha at the high-activity binding site was sequence specific, since nucleotide substitution in this region reduced the binding activity of the WNV 3' SL RNA for EF-1 alpha by approximately 60%. Two low-activity binding sites were also detected, and each accounted for approximately 15 to 20% of the binding activity. Intracellular association between the host protein and the viral RNA was suggested by coimmunoprecipitation of WNV genomic RNA and EF-1 alpha, using an anti-EF-1 alpha antibody.

Ilkal, MA; Mavale, MS; Prasanna, Y; Jacob, PG; Geevarghese, G; Banerjee, K. Experimental studies on the vector potential of certain Culex species to West Nile virus. Indian Journal of Medical Research. 1997 Sep; 106: 225-8. ISSN: 0971-5916.

Descriptors: vector mosquitoes, Culex tritaeniorhynchus, Culex vishnui, Culex bitaeniorhynchus, Culex univittatus, potential as vectors confirmed.

Abstract: Experimental studies were carried out to determine the vector potential of four species of mosquitoes to West Nile (WN) virus, viz. Culex tritaeniorhynchus, Cx. vishnui, Cx. bitaeniorhynchus and Cx. univittatus. All the four species of mosquitoes successfully transmitted and supported the growth of WN virus. The study indicated that the four species of

mosquitoes could act as potential vectors of WN virus in nature.

Return to Contents

February 26, 2003