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The TY3 Gag3 Spacer Controls Intracellular Condensation and Uncoating

Published on Apr 1, 2011in Journal of Virology4.32
· DOI :10.1128/JVI.01055-10
Kristina Clemens4
Estimated H-index: 4
(UCI: University of California, Irvine),
Liza S. Z. Larsen6
Estimated H-index: 6
(UCI: University of California, Irvine)
+ 9 AuthorsSuzanne Sandmeyer30
Estimated H-index: 30
Abstract
Cells expressing the yeast retrotransposon Ty3 form concentrated foci of Ty3 proteins and RNA within which virus-like particle (VLP) assembly occurs. Gag3, the major structural protein of the Ty3 retrotransposon, is composed of capsid (CA), spacer (SP), and nucleocapsid (NC) domains analogous to retroviral domains. Unlike the known SP domains of retroviruses, Ty3 SP is highly acidic. The current studies investigated the role of this domain. Although deletion of Ty3 SP dramatically reduced retrotransposition, significant Gag3 processing and cDNA synthesis occurred. Mutations that interfered with cleavage at the SP-NC junction disrupted CA-SP processing, cDNA synthesis, and electron-dense core formation. Mutations that interfered with cleavage of CA-SP allowed cleavage of the SP-NC junction, production of electron-dense cores, and cDNA synthesis but blocked retrotransposition. A mutant in which acidic residues of SP were replaced with alanine failed to form both Gag3 foci and VLPs. We propose a speculative “spring” model for Gag3 during assembly. In the first phase during concentration of Gag3 into foci, intramolecular interactions between negatively charged SP and positively charged NC domains of Gag3 limit multimerization. In the second phase, the NC domain binds RNA, and the bound form is stabilized by intermolecular interactions with the SP domain. These interactions promote CA domain multimerization. In the third phase, a negatively charged SP domain destabilizes the remaining CA-SP shell for cDNA release.
  • References (48)
  • Citations (6)
References48
Newest
#1Barbie K. Ganser-Pornillos (Scripps Research Institute)H-Index: 17
#2Mark Yeager (Scripps Research Institute)H-Index: 53
Last.Wesley I. Sundquist (UofU: University of Utah)H-Index: 71
view all 3 authors...
#1Elizabeth R. Wright (California Institute of Technology)H-Index: 25
#2Jordan B. Schooler (California Institute of Technology)H-Index: 2
Last.Grant J. Jensen (California Institute of Technology)H-Index: 54
view all 7 authors...
Cited By6
Newest
#1Virginia Bilanchone (UCI: University of California, Irvine)H-Index: 14
#2Kristina Clemens (UCI: University of California, Irvine)H-Index: 4
Last.Suzanne Sandmeyer (UCI: University of California, Irvine)H-Index: 30
view all 11 authors...
#1Agniva Saha (UGA: University of Georgia)H-Index: 4
#2Jessica A. Mitchell (UGA: University of Georgia)H-Index: 2
Last.David J. Garfinkel (UGA: University of Georgia)H-Index: 34
view all 7 authors...
#1Kristina Clemens (UCI: University of California, Irvine)H-Index: 4
#2Virginia Bilanchone (UCI: University of California, Irvine)H-Index: 14
Last.Suzanne Sandmeyer (UCI: University of California, Irvine)H-Index: 30
view all 6 authors...
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