Heterologous expression of βC1 of <i>Chili leaf curl virus</i> in <i>Pichia pastoris</i>

Abstract

Chili pepper is naturally susceptible to a wide range of viruses in all south Asian countries including Pakistan. Chili leaf curl virus is a monopartite begomovirus having single stranded circular betasatellite. It has one open reading frame βC1, required for pathogenicity determined, symptom induction and viral accumulation. It produces viral symptoms like mosaic, mottling, leaf distortion, vein etching, yellowing, stunting and narrowing of leaves. This study was conducted on the basis of βC1 protein, whether it was expressed in prokaryotic and yeast expression system or not because many viral proteins are lethal for the host organism. For this study, specific set of primers for βC1 were designed and amplified product was inserted into pET32a(+) bacterial and pPIC3.5K Pichia vectors for its expression. βC1 was not expressed in BL21 Escherichia coli expression system, while it was expressed in Pichia pastoris, when it was integrated into the genome through electroporation, and expressed protein was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE). This is the first study demonstrating the possibility of expression of βC1protein using P. pastoris.

Key words: Monopartite begomoviruses, chili leaf curl betasatellite, heterologous expression, Pichia pastoris, betasatellite.