HuR interacts with human immunodeficiency virus type 1 reverse transcriptase, and modulates reverse transcription in infected cells.
Reverse transcription of the genetic material of human immunodeficiency virus type 1 (HIV-1) is a critical step in the replication cycle of this virus. This process, catalyzed by reverse transcriptase (RT), is well characterized at the biochemical level. However, in infected cells, reverse transcription occurs in a multiprotein complex - the reverse transcription complex (RTC) - consisting of viral genomic RNA associated with viral proteins (including RT) and, presumably, as yet uncharacterized cellular proteins. Very little is known about the cellular proteins interacting with the RTC, and with reverse transcriptase in particular. We report here that HIV-1 reverse transcription is affected by the levels of a nucleocytoplasmic shuttling protein - the RNA-binding protein HuR. A direct protein-protein interaction between RT and HuR was observed in a yeast two-hybrid screen and confirmed in vitro by homogenous time-resolved fluorescence (HTRF). We mapped the domain interacting with HuR to the RNAse H domain of RT, and the binding domain for RT to the C-terminus of HuR, partially overlapping the third RRM RNA-binding domain of HuR. HuR silencing with specific siRNAs greatly impaired early and late steps of reverse transcription, significantly inhibiting HIV-1 infection. Moreover, by mutagenesis and immunoprecipitation studies, we could not detect the binding of HuR to the viral RNA. These results suggest that HuR may be involved in and may modulate the reverse transcription reaction of HIV-1, by an as yet unknown mechanism involving a protein-protein interaction with HIV-1 RT.
Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris, France. julie.lemay@kispi.uzh.ch
Julie
J
Lemay
Priscilla
P
Maidou-Peindara
Thomas
T
Bader
Eric
E
Ennifar
Jean-Christophe
JC
Rain
Richard
R
Benarous
Lang Xia
LX
Liu
D000954:Antigens, Surface / Q000378:metabolism*; D001665:Binding Sites; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D015200:Fluoroimmunoassay; D020868:Gene Silencing; D054303:HIV Reverse Transcriptase / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D014779:Virus Replication
D000954:Antigens, Surface; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; D034741:RNA, Small Interfering; D012367:RNA, Viral; D016601:RNA-Binding Proteins; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase