Giardiavirus internal ribosome entry site has an apparently unique mechanism of initiating translation

8Citations
Citations of this article
35Readers
Mendeley users who have this article in their library.

Abstract

Giardiavirus (GLV) utilizes an internal ribosome entry site (IRES) for translation initiation in the early branching eukaryote Giardia lamblia. Unlike most of the viral IRESs among higher eukaryotes, which localize primarily within the 5′-untranslated region (UTR), the GLV IRES comprises 253 nts of 5′UTR and the initial 264 nts in the open-reading-frame (ORF). To test if GLV IRES also functions in higher eukaryotic systems, we examined it in rabbit reticulocyte lysate (RRL) and found that it functions much less efficiently than the IRES from the Encephalomyocarditis virus (EMCV) or Cricket paralysis virus (CrPV). In contrast, both EMCV-IRES and CrPV-IRESs were inactive in transfected Giardia cells. Structure-function analysis indicated that only the stem-loop U5 from the 5′UTR and the stem-loop I plus the downstream box (Dbox) from the ORF of GLV IRES are required for limited IRES function in RRL. Edeine, a translation initiation inhibitor, did not significantly affect the function of GLV IRES in either RRL or Giardia, indicating that a pre-initiation complex is not required for GLV IRES - mediated translation initiation. However, the small ribosomal subunit purified from Giardia did not bind to GLV IRES, indicating that additional protein factors may be necessary. A member of the helicase family IBP1 and two known viral IRES binding proteins La autoantigen and SRp20 have been identified in Giardia that bind to GLV IRES in vitro. These three proteins could be involved in facilitating small ribosome recruitment for initiating translation. © 2009 Garlapati, Wang.

References Powered by Scopus

Internal ribosome entry sites in eukaryotic mRNA molecules

837Citations
N/AReaders
Get full text

A prokaryotic-like mode of cytoplasmic eukaryotic ribosome binding to the initiation codon during internal translation initation of hepatitis C and classical swine fever virus RNAs

642Citations
N/AReaders
Get full text

Hepatitis C virus IRES RNA-induced changes in the conformation of the 40S ribosomal subunit

449Citations
N/AReaders
Get full text

Cited by Powered by Scopus

Three-dimensional structure of a protozoal double-stranded RNA virus that infects the enteric pathogen Giardia lamblia

40Citations
N/AReaders
Get full text

Analysis of new isolates reveals new genome organization and a hypervariable region in infectious myonecrosis virus (IMNV)

15Citations
N/AReaders
Get full text

Giardiavirus: an update

10Citations
N/AReaders
Get full text

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Garlapati, S., & Wang, C. C. (2009). Giardiavirus internal ribosome entry site has an apparently unique mechanism of initiating translation. PLoS ONE, 4(10). https://doi.org/10.1371/journal.pone.0007435

Readers' Seniority

Tooltip

PhD / Post grad / Masters / Doc 12

50%

Researcher 9

38%

Professor / Associate Prof. 3

13%

Readers' Discipline

Tooltip

Agricultural and Biological Sciences 14

54%

Biochemistry, Genetics and Molecular Bi... 8

31%

Medicine and Dentistry 2

8%

Veterinary Science and Veterinary Medic... 2

8%

Save time finding and organizing research with Mendeley

Sign up for free