|High yield secretion of heterologous proteins in Corynebacterium glutamicum using its own Tat-type signal sequence.
Appl. Microbiol. Biotechnol. 91: 677-687. 2011.
H. Teramoto, K. Watanabe, N. Suzuki, M. Inui and H. Yukawa.
|Efficient protein secretion, the basis of large-scale production of many
compounds central to the biotechnology industry, is achieved by signal
peptide and propeptide optimization in addition to optimizing host factors
affecting heterologous protein production. Here, we fused green fluorescent
protein (GFP) to the recently identified Tat-type secretory signal peptide
of CgR0949 to demonstrate a high-yield protein secretion system of Corynebacterium glutamicum. The resultant secretion vector facilitated effective secretion of active-form
GFP (20 mg l(-1)) into C. glutamicum culture medium. The expression of GFP was enhanced 2.9-fold using the
Shine-Dalgarno sequence of triosephosphate isomerase in the secretion vector.
Moreover, GFP drastically accumulated in the culture supernatant upon addition
of calcium chloride even though Ca(2+) addition did neither enhanced the
transcription of gfp nor resulted in the accumulation of cytosolic GFP. Active-form GFP concentration reached 1.8 g l(-1) after 48-h incubation in a jar fermentor. Likewise, α-amylase accumulation in C. glutamicum cultures was also enhanced by Ca(2+) addition, suggesting that Ca(2+)
may affect general protein secretion in C. glutamicum.