title: A new signal sequence for recombinant protein secretion in Pichia pastoris.
abstract: Pichia pastoris is one of the most widely used expression systems for the secretory expression of recombinant proteins. The secretory expression in P. pastoris usually makes use of the prepro MATα sequence from Saccharomyces cerevisiae, which has a dibasic amino acid cleavage site at the end of the signal sequence. This is efficiently processed by Kex2 protease, resulting in the secretion of high levels of proteins to the medium. However, the proteins that are having the internal accessible dibasic amino acids such as KR and RR in the coding region cannot be expressed using this signal sequence, as the protein will be fragmented. We have identified a new signal sequence of 18 amino acids from a P. pastoris protein that can secrete proteins to the medium efficiently. The PMT1-gene-inactivated P. pastoris strain secretes a ~30 kDa protein into the extracellular medium. We have identified this protein by determining its N-terminal amino acid sequence. The protein secreted has four DDDK concatameric internal repeats. This protein was not secreted in the wild-type P. pastoris under normal culture conditions. We show that the 18-amino-acid signal peptide at the N-terminal of this protein is useful for secretion of heterologous proteins in Pichia.
authors: Biocon Research Limited - SEZ Unit, Bengaluru 560 099, India.
authors: Nagaraj
authors: N
authors: Govindappa
authors: Manjunatha
authors: M
authors: Hanumanthappa
authors: Krishna
authors: K
authors: Venkatarangaiah
authors: Sankar
authors: S
authors: Periyasamy
authors: Suma
authors: S
authors: Sreenivas
authors: Rajeev
authors: R
authors: Soni
authors: Kedarnath
authors: K
authors: Sastry
mesh_terms: D010843:Pichia / Q000235:genetics* / Q000378:metabolism*; D021382:Protein Sorting Signals; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D021382:Protein Sorting Signals; D011994:Recombinant Proteins