Determinants of dengue virus NS4A protein oligomerization

Chia Min Lee, Xuping Xie, Jing Zou, Shi Hua Li, Michelle Yue Qi Lee, Hongping Dong, Cheng Feng Qin, Congbao Kang, Pei-Yong Shi

Research output: Contribution to journalArticle

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Abstract

Flavivirus NS4A protein induces host membrane rearrangement and functions as a replication complex component. The molecular details of how flavivirus NS4A exerts these functions remain elusive. Here, we used dengue virus (DENV) as a model to characterize and demonstrate the biological relevance of flavivirus NS4A oligomerization. DENV type 2 (DENV-2) NS4A protein forms oligomers in infected cells or when expressed alone. Deletion mutagenesis mapped amino acids 50 to 76 (spanning the first transmembrane domain [TMD1]) of NS4A as the major determinant for oligomerization, while the N-terminal 50 residues contribute only slightly to the oligomerization. Nuclear magnetic resonance (NMR) analysis of NS4A amino acids 17 to 80 suggests that residues L31, L52, E53, G66, and G67 could participate in oligomerization. Ala substitution for 15 flavivirus conserved NS4A residues revealed that these amino acids are important for viral replication. Among the 15 mutated NS4A residues, 2 amino acids (E50A and G67A) are located within TMD1. Both E50A and G67A attenuated viral replication, decreased NS4A oligomerization, and reduced NS4A protein stability. In contrast, NS4A oligomerization was not affected by the replication-defective mutations (R12A, P49A, and K80A) located outside TMD1. trans complementation experiments showed that expression of wild-type NS4A alone was not sufficient to rescue the replication-lethal NS4A mutants. However, the presence of DENV-2 replicons could partially restore the replication defect of some lethal NS4A mutants (L26A and K80A), but not others (L60A and E122A), suggesting an unidentified mechanism governing the outcome of complementation in a mutant-dependent manner. Collectively, the results have demonstrated the importance of TMD1-mediated NS4A oligomerization in flavivirus replication.

Original languageEnglish (US)
Pages (from-to)6171-6183
Number of pages13
JournalJournal of Virology
Volume89
Issue number12
DOIs
StatePublished - 2015
Externally publishedYes

Fingerprint

Flavivirus
Dengue virus
Amino Acids
Dengue Virus
proteins
amino acids
Galectin 3
Replicon
virus replication
Protein Stability
lethal genes
mutants
Mutagenesis
Magnetic Resonance Spectroscopy
replicon
Mutation
Membranes
oligomerization
Dengue virus NS4A protein
mutagenesis

ASJC Scopus subject areas

  • Immunology
  • Virology
  • Medicine(all)

Cite this

Lee, C. M., Xie, X., Zou, J., Li, S. H., Qi Lee, M. Y., Dong, H., ... Shi, P-Y. (2015). Determinants of dengue virus NS4A protein oligomerization. Journal of Virology, 89(12), 6171-6183. https://doi.org/10.1128/JVI.00546-15

Determinants of dengue virus NS4A protein oligomerization. / Lee, Chia Min; Xie, Xuping; Zou, Jing; Li, Shi Hua; Qi Lee, Michelle Yue; Dong, Hongping; Qin, Cheng Feng; Kang, Congbao; Shi, Pei-Yong.

In: Journal of Virology, Vol. 89, No. 12, 2015, p. 6171-6183.

Research output: Contribution to journalArticle

Lee, CM, Xie, X, Zou, J, Li, SH, Qi Lee, MY, Dong, H, Qin, CF, Kang, C & Shi, P-Y 2015, 'Determinants of dengue virus NS4A protein oligomerization', Journal of Virology, vol. 89, no. 12, pp. 6171-6183. https://doi.org/10.1128/JVI.00546-15
Lee CM, Xie X, Zou J, Li SH, Qi Lee MY, Dong H et al. Determinants of dengue virus NS4A protein oligomerization. Journal of Virology. 2015;89(12):6171-6183. https://doi.org/10.1128/JVI.00546-15
Lee, Chia Min ; Xie, Xuping ; Zou, Jing ; Li, Shi Hua ; Qi Lee, Michelle Yue ; Dong, Hongping ; Qin, Cheng Feng ; Kang, Congbao ; Shi, Pei-Yong. / Determinants of dengue virus NS4A protein oligomerization. In: Journal of Virology. 2015 ; Vol. 89, No. 12. pp. 6171-6183.
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