BIANNUALREPORT2012-2013

Chloroplasts, isoprenoids, and protein quality control

Chloroplasts are the main factory for the production of plant metabolites. Among them, isoprenoids are essential for photosynthesis and plant development, but they also have a great interest to the pharmaceutical and food industries. A team led by CSIC investigator Manuel Rodriguez-Concepción discovered that the activity of the main enzyme regulating the production of chloroplast isoprenoids (named DXS) depends on its interaction with J20, a co-chaperone protein. The work demonstrates that J20 recognizes inactive forms of DXS and transfers them to the molecular chaperone Hsp70. Upon interaction with Hsp70, the misfolded forms of DXS are either refolded back to their enzymatically active form or unfolded for their eventual degradation. This discovery opens the door to new strategies to enrich crops in isoprenoid metabolites of nutritional or industrial interest.