PrPC has nucleic acid chaperoning properties similar to the nucleocapsid protein of HIV-1.
The function of the cellular prion protein (PrPC) remains obscure. Studies suggest that PrPC functions in several processes including signal transduction and Cu2+ metabolism. PrPC has also been established to bind nucleic acids. Therefore we investigated the properties of PrPC as a putative nucleic acid chaperone. Surprisingly, PrPC possesses all the nucleic acid chaperoning properties previously specific to retroviral nucleocapsid proteins. PrPC appears to be a molecular mimic of NCP7, the nucleocapsid protein of HIV-1. Thus PrPC, like NCP7, chaperones the annealing of tRNA(Lys) to the HIV-1 primer binding site, the initial step of retrovirus replication. PrPC also chaperones the two DNA strand transfers required for production of a complete proviral DNA with LTRs. Concerning the functions of NCP7 during budding, PrPC also mimices NCP7 by dimerizing the HIV-1 genomic RNA. These data are unprecedented because, although many cellular proteins have been identified as nucleic acid chaperones, none have the properties of retroviral nucleocapsid proteins.
Derrington
Edmund
E
Laboretro, unité de virologie humaine, Inserm-ENS U412, ENS de Lyon, 46, allée d'Italie, 69364 Lyon, France.
Gabus
Caroline
C
Leblanc
Pascal
P
Chnaidermann
Jonas
J
Grave
Linda
L
Dormont
Dominique
D
Swietnicki
Wieslaw
W
Morillas
Manuel
M
Marck
Daniel
D
Nandi
Pradip
P
Darlix
Jean-Luc
JL
D001665:Binding Sites; D002213:Capsid / Q000502:physiology*; D036022:Capsid Proteins; D004277:DNA, Single-Stranded / Q000096:biosynthesis; D004279:DNA, Viral / Q000096:biosynthesis; D019281:Dimerization; D015683:Gene Products, gag / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics; D018832:Molecular Chaperones / Q000502:physiology*; D009696:Nucleic Acids / Q000378:metabolism*; D018621:PrPC Proteins / Q000502:physiology*; D012357:RNA, Transfer, Lys / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry; D014158:Transcription, Genetic; D014764:Viral Proteins; D014779:Virus Replication; D054301:gag Gene Products, Human Immunodeficiency Virus
D036022:Capsid Proteins; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D015683:Gene Products, gag; D018832:Molecular Chaperones; C071884:NCP7 protein, Human immunodeficiency virus 1; D009696:Nucleic Acids; D018621:PrPC Proteins; D012357:RNA, Transfer, Lys; D012367:RNA, Viral; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus