Secretory production method for protein

A method for producing a heterologous protein comprising:

• culturing a coryneform bacterium having a genetic construct for secretory expression of the heterologous protein;
• and
• collecting the heterologous protein produced by secretory production,
• wherein the coryneform bacterium has been modified to reduce molecules of a RegX3 protein per cell as compared to a non-modified bacterium,
• wherein the coryneform bacterium is Corynebacterium glutamicum,
• wherein the genetic construct comprises, in the direction from 5′ to 3′, a promoter sequence that functions in the coryneform bacterium, a nucleic acid sequence encoding a signal peptide that functions in the coryneform bacterium, and a nucleic acid sequence encoding the heterologous protein,
• wherein the heterologous protein is expressed as a fusion protein with the signal peptide;
• wherein the molecules of the RegX3 protein per cell is reduced by reducing the expression of a regX3 gene, or by disrupting a regX3 gene, and
• wherein the RegX3 protein is selected from the group consisting of:
• (a) a protein comprising the amino acid sequence of SEQ ID NO:
• 65;
• (b) a protein comprising the amino acid sequence of SEQ ID NO:
• 65, said protein comprising 1 to 10 amino acid residue substitution, deletion, insertion, and/or addition and is a response regulator of a SenX3-RegX3 system;
• and
• (c) a protein comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:
• 65, and is a response regulator of a SenX3-RegX3 system.