INVITRO MEMBRANE-BINDING OF THE TRANSLATION PRODUCTS OF THE CARLAVIRUS 7-KDA PROTEIN GENES

Two double-stranded DNA copies of the genes potentially coding for the 7-kDa proteins of potato virus M (PVM) and potato virus S(PVS) were synthesized and cloned into T7 transcription vectors. Cell-free translation of the corresponding monocistronic transcripts yielded in both cases a single protein of approximately 7-8 kDa that contains a highly hydrophobic N-terminal segment. To analyze their membrane-binding potential, both proteins were synthesized in the membrane-enriched Krebs-2 extract. It was found that the smooth membrane fraction was enriched in the carlavirus 7-kDa proteins. The primary and predicted secondary structures of their N-terminal hydrophobic segments suggest that the latter can function as signals for translocation into the rough endoplasmic reticulum. © 1991.