Interrelationship between Cytoplasmic Retroviral Gag Concentration and Gag-Membrane Association

JOURNAL OF MOLECULAR BIOLOGY

卷:426

Article

Fogarty, Keir H.^1,2,3  Berk, Serkan^1,4  Grigsby, Iwen F.^1,2  Chen, Yan^1,3  Mansky, Louis M.^1,2,5  Mueller, Joachim D.^1,3,4 

[1] Univ Minnesota, Inst Mol Virol, Minneapolis, MN 55455 USA

[2] Univ Minnesota, Sch Dent, Dept Diagnost & Biol Sci, Minneapolis, MN 55455 USA

[3] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA

[4] Univ Minnesota, Dept Biomed Engn, Minneapolis, MN 55455 USA

[5] Univ Minnesota, Dept Microbiol, Minneapolis, MN 55455 USA

关键词: fluorescence;    retrovirus;    assembly;    oligomerization;    membrane;   

DOI  :  10.1016/j.jmb.2013.11.025

来源: Elsevier

【 摘 要 】

The early events in the retrovirus assembly pathway, particularly the timing and nature of Gag translocation from the site of protein translation to the inner leaflet of the plasma membrane, are poorly understood. We have investigated the interrelationship between cytoplasmic Gag concentration and plasma membrane association using complementary live-cell biophysical fluorescence techniques in real time with both human T-cell leukemia virus type 1 (HTLV-1) and human immunodeficiency virus type 1 (HIV-1) Gag proteins. In particular, dual-color, z-scan fluorescence fluctuation spectroscopy in conjunction with total internal reflection fluorescence and conventional, epi-illumination imaging were utilized. Our results demonstrate that HTLV-1 Gag is capable of membrane targeting and particle assembly at low (i.e., nanomolar) cytoplasmic concentrations and that there is a critical threshold concentration (approaching micromolar) prior to the observation of HIV-1 Gag associated with the plasma membrane. These observations imply fundamental differences between HIV-1 and HTLV-1 Gag trafficking and membrane association. (c) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

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