The transcriptional responses of C. glutamicum to the secretory production of two different heterologous proteins

High level secretion of proteins via the Sec protein export pathway leads to secretion stress, a phenomenon that is thought to be caused by the accumulation of incompletely or misfolded proteins at the membrane-cell envelope interface. We have analyzed the transcriptional responses of C. glutamicum to the secretory production of two different heterologous proteins and found that, in both cases, the expression of the gene encoding a homologue of the extracytosolic HtrA protease was highly upregulated. Transcriptional responses of C. glutamicum to the secretory production of heterologous proteins were determined in 3 sets. Set 1 comprises 3 biological replicates of C.glutamicum WT carrying plasmid for expression of AmyE without signal peptide. Set 2 comprises 3 biological replicates of C.glutamicum WT carrying plasmid for expression of AmyE fused with signal peptide. Set 3 comprises 3 biological replicates of C.glutamicum WT carrying plasmid for expression of cutinase fused with NprE signal peptide. In all sets/replicates the induced culture was compared to the uninduced culture.