Translational regulations as specific traits of chloroplast gene expression.

Studies of protein synthesis in the chloroplast compartment have revealed a unique combination of translational autoregulations and trans-regulations due to the delivery of a variety of nuclear factors that act post-transcriptionally. We show how these two characteristics concur to set the major step in the regulation of chloroplast gene expression at the translational level, leading to a surprisingly low sensitivity of chloroplast protein synthesis in response to extensive changes in plastome copy number and transcript concentration.