Table 1

Links between components of RNA trafficking granules and retroviral replication

RTG Component

Cellular Function

Link to Retroviral Replication Cycle

Virion-Incorporation

Reference*

Actin

Cytoskeletal component for cell structure; scaffold for intracellular trafficking

Acts with HIV-1 Rev to promote nucleo-cytoplasmic RNA Transport; Binds retroviral Gags

Yes

[178–181]

DDX1, 3, 5

RNA Helicases involved in RNA splicing, nuclear RNA export, RNA translation)

Promotes genomic RNA Nucleocyto-plasmic export

?

[113]

EF1α

Translation elongation factor involved in RNA anchoring via the actin cytoskeleton and in RNA translation

Binds HIV-1 Gag and may inhibit Gag RNA translation to favour encapsidation

Yes

[182]

eIF5A

Translation initiation factor involved in RNA translation initiation

A cofactor in Rev-mediated nucleocyto-plasmic RNA transport

?

[178, 183]

hnRNP A/B

Family of pre-mRNA splicing factors involved in RNA Splicing, RNA nucleocytoplasmic export, RNA trafficking

Influences retroviral RNA pre-mRNA splicing, RNA trafficking and gene expression

No

[34, 64, 133, 151]

Hsp70

Heat shock protein serving as a protein chaperone following heat or cellular stress

Promotes viral assembly, binds HIV-1 Vpr and promotes pre-integration complex nuclear nuclear import

Yes

[184–187]

Kinesin-1** (KIF-5, KHC)

Molecular motor protein involved in energy-dependent intracellular translocation

The kinesin, KIF-4, interacts with retro-viral Gag Proteins

?

[168, 169]

Nucleolin

RNA binding or chaperone protein with numerous nuclear functions: remodeling of chromatin structure, ribosomal DNA transcription, ribosomal RNA maturation, ribosome assembly and nucleocytoplasmic transport

Binds genomic RNA of MLV and HIV-1

Yes (MLV)

[188, 189]

PABP1

Poly(A) tail binding protein involved in RNA translation and RNA stability

Binds HIV-1 instability (INS) RNA sequences

?

[190]

PSF

Pre-mRNA splicing factor associated to polypyrimidine tract binding protein; Co-transcriptional RNA splicing

Interacts with HIV-1 cis-repressor (CRS) or INS RNA sequences

?

[191]

Pur1α

DNA- and RNA-binding protein involved in transcription and RNA transport

Binds TAR/Tat and can transactivate the HIV-1 LTR

?

[192–194]

RHA

RNA Helicase involved in RNA splicing and nuclear RNA export

Nucleocytoplasmic export and translation of genomic RNA

?

[156, 157] & K. Boris-Lawrie, personal communication

Staufen1***

Double-stranded RNA-binding protein involved in RNA trafficking & metabolism

Binds pr55^Gag and is in the genomic RNA ribonucleoprotein complex

Yes

[172, 175]

tRNA synthetases

Enzyme catalyzing the synthesis of tRNAs for RNA translation

Binds retroviral Gag and is virion incorporated

Yes

[195, 196]

* Proteins identified in the RTG reported in the following references: [160, 197]; ** related kinesin molecular motor protein; *** HIV-1 pr55^Gag should be considered part of a putative HIV-1 RTG since it is found in the Staufen1 complex ([172] and M. Milev & A.J.M., unpublished).

Cochrane et al. Retrovirology 2006 3:18   doi:10.1186/1742-4690-3-18