AEGiS-13IAC: Characterisation of the ancient Rev homologue Corf.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

Characterisation of the ancient Rev homologue Corf.

Int Conf AIDS 2000 Jul 9-14; 13:34 (abstract no.. LbPeA7010)

Lower R, Magin C, Steinhauser KC, Strobel H, Held U, Lower J
Paul-Ehrlich-Institut, Virology Department, Langen, Germany. Fax: +49 6103 77 1265, E-mail: loero@pei.de.

BACKGROUND: Regulation of nucleo-cytoplasmic export of viral transcripts by a viral protein (Rev/Rex) is a characteristic feature in the replication cycle of complex retroviruses. We recently reported that the endogenous retrovirus family HTDV/HERV-K encodes a protein, Corf, which is a cellular counterpart of Rev/Rex function.

METHODS: Using wild-type and mutated corf expression vectors in immuno-fluorescence studies, domains were characterised which are relevant for the nucleo-cytoplasmic shuttling of this regulatory protein. Co-transfections of a HIV gag based reporter construct carrying the Corf responsive element with either wild-type or mutant Corf expression plasmids were used to analyse whether or not Corf function was affected by the respective mutations.

RESULTS: Using this approach two domains were identified which were relevant for nucleo-cytoplasmic shuttling as well as for Corf function: the nuclear import domain NLS and the nuclear export domain NES. In contrast to what has been published for lentivirus NES domains, the Corf NES domain could not replace the Rev NES domain in functional assays although both proteins have been reported to bind to the same export receptor CRM1.

CONCLUSIONS: Although Corf displays a similar function as Rev - nuclear export of unspliced and incompletely spliced viral transcripts - differences in the NES domains hint to usage of different export receptors.

Keywords: AEGIS, Endogenous Retroviruses, Cytoplasm, Carrier Proteins, Viral Proteins, Transfection, Proteins, Active Transport, Cell Nucleus, Greece, genetics, AIDS
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