Mechanisms to Increase the Production of Recombinant Proteins in Plant Chloroplasts

Molecular farming is the use of plants to produce valuable pharmaceutical proteins in the bulky and cost-effective manner. Molecular farming and the production of recombinant proteins (such as insulin، interferon-gamma، tissue plasminogen activator، etc.) in transplastomic plants، has achieved a great success in Iran. Due to the growing demand for recombinant proteins، the selection of a proper expression system is very important. Chloroplast genome engineering، for its many advantages، is one of the suitable methods for the production of recombinant proteins. To achieve high levels of recombinant proteins in chloroplasts، plastid’s specific transcription، translation and post-translational modifications should be considered. Some of the strategies used for increasing of foreign proteins in chloroplast can be mentioned: gene insertion in the suitable site in chloroplast genome، use of strong promoters، appropriate regulatory sequences in the 5'' and 3'' UTRs، codon optimization، and utilization of factors enhancing protein stability such as chaperons and fusion proteins. In this article، besides a brief description about chloroplast and its genome، methods for enhancing recombinant protein production in transplastomic plants were discussed.