Premium
Investigating the Role of Threonylcarbamoyl Adenosine in HIV‐1 Replication in vivo
Author(s) -
Kirkland Marina,
Venketaraman Vishwanath,
Swairjo Manal
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.711.19
Subject(s) - biology , transfer rna , gene , gene knockdown , primer binding site , transcription (linguistics) , rna , reverse transcriptase , viral replication , microbiology and biotechnology , genetics , virus , linguistics , philosophy
In all retroviruses, reverse transcription of viral genes is primed by a host‐cell tRNA whose 3′‐end 18 nucleotides are complementary to the viral primer binding site. For lentiviruses, including HIV, the natural primer is tRNA Lys3 which harbors several modified bases in its anticodon stem‐loop (ASL). Interaction of the fully modified ASL with the HIV RNA template is required for efficient reverse transcription of viral RNA, and continuation of viral life cycle. One of the modified nucleosides of the ASL of tRNA Lys3 is N 6 ‐threonylcarbamoyl adenosine (t 6 A 37 ), a universally conserved modification found at position 37 in all tRNAs decoding ANN codons. t 6 A 37 stabilizes the ASL structure and prevents ribosomal frameshifting in the course of translation. Eukaryotic t 6 A 37 biosynthesis is catalyzed by the enzyme Sua5 and the KEOPS complex, comprised of the four subunits Kae1, Pcc1, Bud32 and Cgi121. We hypothesize that t 6 A 37 plays an important role in viral replication in vivo , by stabilizing ASL structure or by direct interaction with viral RNA. To test this hypothesis, we set out to suppress the biosynthesis of t 6 A 37 in CD4+ cells by targeting its biosynthesis genes with siRNA and testing viral load upon HIV‐1 infection. Background expression levels of the core human t 6 A 37 biosynthesis gene Osgep ( Kae1 ortholog) were determined by qRT‐PCR. Treatment with anti‐OSGEP siRNA resulted in knockdown of Osgep expression by 60% 48 hrs post‐transfection and sustained for 72 hrs, 4 times longer than the reported half‐life of OSGEP protein in human cells.