Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


12-1-14 Rye_McCurdy_Dissertation.pdf (19.23 MB)

ETD Abstract Container

Abstract Header

The role of Rous sarcoma virus Gag in tRNA primer annealing and genomic RNA encapsidation

Rye-McCurdy, Tiffiny
http://rave.ohiolink.edu/etdc/view?acc_num=osu1417444366

Abstract Details

2014, Doctor of Philosophy, Ohio State University, Biochemistry Program, Ohio State.
The hallmark of a retrovirus is the ability to reverse transcribe single-stranded genomic RNA (gRNA) into double-stranded DNA for subsequent integration into the host cell genome. After integration, the host cell machinery takes over; thus, viral DNA is transcribed into RNA and translated into viral proteins such as Gag. The Gag polyprotein, consisting of domains matrix (MA), capsid (CA), and nucleocapsid (NC), contributes to almost every stage of the retroviral lifecycle, including reverse transcription and gRNA encapsidation. Host cell tRNALys3 and tRNATrp serve as the primers for reverse transcription in human immunodeficiency virus type 1 (HIV-1) and Rous sarcoma virus (RSV), respectively. The NC domain of Gag facilitates tRNA primer annealing to the complementary primer binding site (PBS) in the viral genome, which initiates reverse transcription. Previous in vitro studies showed MA has an inhibitory effect on HIV-1 Gag nucleic acid (NA) chaperone activity and this inhibition can be reversed in the presence of inositol hexaphosphate (IP6). Taken together, these data suggested that IP6 binds to MA and displaces it from nucleic acid, thus stimulating the NA chaperone activity of HIV-1 Gag. In addition, the NC domain of Gag is responsible for binding a packaging signal (psi) in gRNA to facilitate the selective incorporation of gRNA into virions during assembly. A salt-titration approach demonstrated HIV-1 Gag binds psi-containing RNA (psi RNA) with greater specificity and fewer electrostatic interactions when compared to RNA lacking psi (non-psi RNA). Whereas extensive studies have been carried out in HIV-1, little is known about the NA chaperone activity of RSV Gag. In this work, I examine the NA chaperone activity of RSV Gag in vitro. Similar to HIV-1, RSV NC is required for Gag-facilitated tRNA primer annealng to the RSV PBS. In contrast to HIV-1, MA does not inhibit the NA chaperone activity of Gag and I observed no IP6-dependent stimulation in Gag-facilitated tRNA annealing to the PBS in RSV. Additionally, in this work I examine the salt-dependence of binding of RSV Gag to psi and non-psi RNA. Similar to HIV-1, RSV Gag binding to psi RNA was characterized by significantly greater specificity and 4-5 fewer electrostatic contacts when compared to non-psi RNA. More importantly, Gag lacking the MA domain exhibited similar binding to both RNAs. This suggests that MA contributes to the selectivity of RSV Gag for psi RNA over non-psi RNA, although, the mechanism is still unclear.
Karin Musier-Forsyth (Advisor)
James Hopper (Committee Member)
Kathleen Boris-Lawrie (Committee Member)
David Bisaro (Committee Member)
147 p.
Biochemistry; Virology
HIV-1; RSV; Gag; nucleocapsid; psi RNA, nucleic acid chaperone, genomic RNA packaging, tRNA

Recommended Citations

Citations

  • Rye-McCurdy, T. (2014). The role of Rous sarcoma virus Gag in tRNA primer annealing and genomic RNA encapsidation [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417444366

    APA Style (7th edition)

  • Rye-McCurdy, Tiffiny. The role of Rous sarcoma virus Gag in tRNA primer annealing and genomic RNA encapsidation. 2014. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1417444366.

    MLA Style (8th edition)

  • Rye-McCurdy, Tiffiny. "The role of Rous sarcoma virus Gag in tRNA primer annealing and genomic RNA encapsidation." Doctoral dissertation, Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417444366

    Chicago Manual of Style (17th edition)

osu1417444366
235
© 2014, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.