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Burgard J, Grünwald-Gruber C, Altmann F, Zanghellini J, Valli M, Mattanovich D, Gasser B. The secretome of Pichia pastoris in fed-batch cultivations is largely independent of the carbon source but changes quantitatively over cultivation time. Microb Biotechnol 2019; 13:479-494. [PMID: 31692260 PMCID: PMC7017826 DOI: 10.1111/1751-7915.13499] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 10/07/2019] [Indexed: 01/20/2023] Open
Abstract
The quantitative changes of the secretome of recombinant Pichia pastoris (Komagataella phaffii) CBS7435 over the time-course of methanol- or glucose-limited fed-batch cultures were investigated by LC-ESI-MS/MS to define the carbon source-specific secretomes under controlled bioreactor conditions. In both set-ups, no indication for elevated cell lysis was found. The quantitative data revealed that intact and viable P. pastoris cells secrete only a low number of endogenous proteins (in total 51), even during high cell density cultivation. Interestingly, no marked differences in the functional composition of the P. pastoris secretome between methanol- and glucose-grown cultures were observed with only few proteins being specifically affected by the carbon source. The 'core secretome' of 22 proteins present in all analysed carbon sources (glycerol, glucose and methanol) consists mainly of cell wall proteins. The quantitative analysis additionally revealed that most secretome proteins were already present after the batch phase, and depletion rather than accumulation occurred during the fed-batch processes. Among the changes over cultivation time, the depletion of both the extracellularly detected chaperones and the only two identified proteases (Pep4 and Yps1-1) during the methanol- or glucose-feed phase appear as most prominent.
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Affiliation(s)
- Jonas Burgard
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Clemens Grünwald-Gruber
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Friedrich Altmann
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Jürgen Zanghellini
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria.,Austrian Biotech University of Applied Sciences, Tulln, Austria
| | - Minoska Valli
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Diethard Mattanovich
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Brigitte Gasser
- Austrian Centre of Industrial Biotechnology (acib), Vienna, Austria.,Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
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Vai M, Brambilla L, Orlandi I, Rota N, Ranzi BM, Alberghina L, Porro D. Improved secretion of native human insulin-like growth factor 1 from gas1 mutant Saccharomyces cerevisiae cells. Appl Environ Microbiol 2000; 66:5477-9. [PMID: 11097931 PMCID: PMC92485 DOI: 10.1128/aem.66.12.5477-5479.2000] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We studied the secretion of recombinant human insulin-like growth factor 1 (rhIGF-1) from transformed yeast cells. The hIGF-1 gene was fused to the mating factor alpha prepro- leader sequence under the control of the constitutive ACT1 promoter. We found that the inactivation of the GAS1 gene in the host strain led to a supersecretory phenotype yielding a considerable increase, from 8 to 55 mg/liter, in rhIGF-1 production.
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Affiliation(s)
- M Vai
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milan, Italy
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Pirone TP, Blanc S. Helper-dependent vector transmission of plant viruses. ANNUAL REVIEW OF PHYTOPATHOLOGY 1996; 34:227-47. [PMID: 15012542 DOI: 10.1146/annurev.phyto.34.1.227] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A variety of noncirculatively transmitted viruses have evolved a vector transmission strategy that involves, in addition to virions, virus-encoded proteins that are not constituents of virions. These "helpers" and the genes encoding them have been characterized for viruses in the genera Potyvirus and Caulimovirus. Several lines of evidence support the hypothesis that these helpers act by mediating retention of virions in regions of the vector's alimentary tract from which they subsequently can be egested to initiate an infection. The possible advantage this convergently evolved strategy could confer to noncirculatively transmitted virus quasispecies is discussed.
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Affiliation(s)
- T P Pirone
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546, USA
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Abstract
The solubility and secretability of proteins can often be affected by extremely small changes in their primary structure. Attempts to determine empirical rules for the alteration of protein structure to improve either of these characteristics have met with only partial success. Those (mostly serendipitous) improvements in solubility that have been obtained via mutagenesis cannot be considered to be 'protein engineering'. The most successful examples where directed mutagenesis has been used to alter protein solubility, hemoglobin and insulin, have relied on established crystal structures and a wealth of data about the relationship between sequence and structure of the targeted protein. Currently, optimizing culture growth conditions by trial and error remains the fastest way to improve expression.
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Affiliation(s)
- C H Schein
- Department of Pharmacy, Swiss Federal Institute of Technology, Zurich
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Chaudhuri B, Latham SE, Stephan C. A mutant Kex2 enzyme with a C-terminal HDEL sequence releases correctly folded human insulin-like growth factor-1 from a precursor accumulated in the yeast endoplasmic reticulum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 210:811-22. [PMID: 1483466 DOI: 10.1111/j.1432-1033.1992.tb17484.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mutations in the pro region of the yeast DNA hybrid of prepro-alpha-factor and human insulin-like growth factor-1 (IGF-1) cause the accumulation, in the yeast Saccharomyces cerevisiae, of an unglycosylated precursor protein where the pre sequence is missing. The prepro sequence of the prepro-alpha-factor consists of a pre or signal sequence and a proregion which possesses three sites for N-glycosylation. Isolation of a precursor, where the pro region is still linked to IGF-1 through a pair of dibasic amino acid residues, implies that the polypeptide may have translocated into the endoplasmic reticulum (ER) but has not been processed by the Golgi membrane-bound Kex2 endoprotease. However, the lack of any N-glycosylation in the translocated polypeptide is surprising. The mutated pro region, can be processed, in vitro, by treatment with a soluble form of the Kex2 enzyme. It is also possible to release the pro region, in vivo, by coexpressing a mutant Kex2 protease which is partially retained in the ER with the help of the C-terminal tetrapeptide sequence, HDEL. The mature IGF-1, which is secreted from the intracellular pool of precursor proteins, is predominantly an active, monomeric molecule, corroborating observations that early removal of the pro region before folding in the ER helps to prevent aberrant intermolecular disulfide-bond formation in IGF-1. These results have revealed the utility of the ER-retained Kex2 enzyme as a novel in vivo biochemical tool.
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Affiliation(s)
- B Chaudhuri
- Department of Biotechnology, Ciba-Geigy Ltd., Basel, Switzerland
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Atreya CD, Atreya PL, Thornbury DW, Pirone TP. Site-directed mutations in the potyvirus HC-Pro gene affect helper component activity, virus accumulation, and symptom expression in infected tobacco plants. Virology 1992; 191:106-11. [PMID: 1413497 DOI: 10.1016/0042-6822(92)90171-k] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Helper component (HC-Pro) is a virus-encoded nonstructural protein required for aphid transmission of potyviruses. In the tobacco vein mottling virus (TVMV) polyprotein, HC-Pro represents a 457 residue polypeptide from amino acid position 257 to 713. Previous sequence comparison studies have suggested that mutations of one or two specific amino acid residues in the HC-Pro protein might result in loss of aphid transmission activity. To test this hypothesis, the initial targets were the residues corresponding to these specific amino acids, a lys to glu change and an ile to val change at amino acid positions 307 and 482, respectively, of the TVMV polyprotein, as well as the combination of the two. Two additional mutations within the HC-Pro representing dipeptide changes thr-ser to ile-asp and thr-ala to leu-glu at amino acid positions (283/284) and (368/369), respectively, were also tested to further define the effects of mutations in this region on helper component activity. The mutations at positions 482 and (368/369) had no effect on aphid transmission activity, while mutation at position 307 completely abolished the activity. Except for the 482 mutation, all the mutations also affected symptomatology and virus accumulation in infected plants. Due to the very low concentrations of HC-Pro in plants infected with the (283/284) mutant, the effect of this dipeptide change on aphid transmission activity could not be assessed. The majority of the tested mutations fall within a putative zinc-finger motif postulated in the cysteine-rich N-terminus of HC-Pro. The possible role of this motif in the potyviruses is further discussed in the light of our present results with TVMV.
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Affiliation(s)
- C D Atreya
- Department of Plant Pathology, University of Kentucky, Lexington 40546
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Chaudhuri B, Stephan C. A modified Kex2 enzyme retained in the endoplasmic reticulum prevents disulfide-linked dimerisation of recombinant human insulin-like growth factor-1 secreted from yeast. FEBS Lett 1992; 304:41-5. [PMID: 1618297 DOI: 10.1016/0014-5793(92)80585-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The majority of the recombinant human insulin-like growth factor-1 (IGF1) molecules, secreted from yeast using the prepro sequence of the prepro-alpha-factor, are not active monomers but inactive, disulfide-linked dimers. The prepro sequence of the prepro-alpha-factor, usually referred to as the alpha-factor leader (alpha FL), consists of a pre or signal sequence and a proregion. After signal sequence removal during translocation into the endoplasmic reticulum (ER) the proregion is still attached to IGF1 when it folds to acquire a tertiary structure. Mature IGF1 is released only in a late Golgi compartment by the membrane-bound endoprotease Kex2p. We find that co-expression of a novel ER-retained Kex2p variant, soluble Kex2pHDEL, can prevent intermolecular disulfide bond formation between two IGF1 molecules, implying that the presence of the proregion during the folding of IGF1 in the ER could be a reason for disulfide-linked dimerisation. This result indicates that the proregion of the alpha FL may have a role in the folding of some heterologous proteins in yeast, and that the ER-retained Kex2p mutant could be used as a convenient tool to study the cellular function of the proregions present naturally in various eucaryotic precursor proteins.
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Affiliation(s)
- B Chaudhuri
- Department of Biotechnology, Ciba-Geigy Ltd., Basel, Switzerland
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