scholarly journals A Novel Potent Carrier for Unconventional Protein Export in Ustilago maydis

2022 ◽  
Vol 9 ◽  
Author(s):  
Magnus Philipp ◽  
Kai P. Hussnaetter ◽  
Michèle Reindl ◽  
Kira Müntjes ◽  
Michael Feldbrügge ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Full Range ◽  
Ustilago Maydis ◽  
Firefly Luciferase ◽  
Protein Export ◽  
Spike Protein ◽  
Heterologous Proteins ◽  
Reporter Activity ◽  
Unconventional Secretion ◽  
Protein Functions

Recombinant proteins are ubiquitously applied in fields like research, pharma, diagnostics or the chemical industry. To provide the full range of useful proteins, novel expression hosts need to be established for proteins that are not sufficiently produced by the standard platform organisms. Unconventional secretion in the fungal model Ustilago maydis is an attractive novel option for export of heterologous proteins without N-glycosylation using chitinase Cts1 as a carrier. Recently, a novel factor essential for unconventional Cts1 secretion termed Jps1 was identified. Here, we show that Jps1 is unconventionally secreted using a fusion to bacterial β-glucuronidase as an established reporter. Interestingly, the experiment also demonstrates that the protein functions as an alternative carrier for heterologous proteins, showing about 2-fold higher reporter activity than the Cts1 fusion in the supernatant. In addition, Jps1-mediated secretion even allowed for efficient export of functional firefly luciferase as a novel secretion target which could not be achieved with Cts1. As an application for a relevant pharmaceutical target, export of functional bi-specific synthetic nanobodies directed against the SARS-CoV2 spike protein was demonstrated. The establishment of an alternative efficient carrier thus constitutes an excellent expansion of the existing secretion platform.

scholarly journals Controlling Unconventional Secretion for Production of Heterologous Proteins in Ustilago maydis through Transcriptional Regulation and Chemical Inhibition of the Kinase Don3

2021 ◽  
Vol 7 (3) ◽  
pp. 179
Author(s):  
Kai P. Hussnaetter ◽  
Magnus Philipp ◽  
Kira Müntjes ◽  
Michael Feldbrügge ◽  
Kerstin Schipper
Keyword(s):  
Protein Production ◽  
Heterologous Protein ◽  
Ustilago Maydis ◽  
Downstream Processing ◽  
Culture Broth ◽  
Yeast Cells ◽  
Heterologous Protein Expression ◽  
Heterologous Proteins ◽  
Regulatory Systems ◽  
Unconventional Secretion

Heterologous protein production is a highly demanded biotechnological process. Secretion of the product to the culture broth is advantageous because it drastically reduces downstream processing costs. We exploit unconventional secretion for heterologous protein expression in the fungal model microorganism Ustilago maydis. Proteins of interest are fused to carrier chitinase Cts1 for export via the fragmentation zone of dividing yeast cells in a lock-type mechanism. The kinase Don3 is essential for functional assembly of the fragmentation zone and hence, for release of Cts1-fusion proteins. Here, we are first to develop regulatory systems for unconventional protein secretion using Don3 as a gatekeeper to control when export occurs. This enables uncoupling the accumulation of biomass and protein synthesis of a product of choice from its export. Regulation was successfully established at two different levels using transcriptional and post-translational induction strategies. As a proof-of-principle, we applied autoinduction based on transcriptional don3 regulation for the production and secretion of functional anti-Gfp nanobodies. The presented developments comprise tailored solutions for differentially prized products and thus constitute another important step towards a competitive protein production platform.

Applying unconventional secretion of the endochitinase Cts1 to export heterologous proteins in Ustilago maydis

2012 ◽  
Vol 161 (2) ◽  
pp. 80-91 ◽  
Author(s):  
Janpeter Stock ◽  
Parveen Sarkari ◽  
Saskia Kreibich ◽  
Thomas Brefort ◽  
Michael Feldbrügge ◽  
...  
Keyword(s):  
Ustilago Maydis ◽  
Heterologous Proteins ◽  
Unconventional Secretion

scholarly journals Lactiplantibacillus plantarum as a Potential Adjuvant and Delivery System for the Development of SARS-CoV-2 Oral Vaccines

2021 ◽  
Vol 9 (4) ◽  
pp. 683
Author(s):  
Julio Villena ◽  
Chang Li ◽  
Maria Guadalupe Vizoso-Pinto ◽  
Jacinto Sacur ◽  
Linzhu Ren ◽  
...  
Keyword(s):  
Immune Responses ◽  
Oral Administration ◽  
Molecular Mechanisms ◽  
Spike Protein ◽  
Heterologous Proteins ◽  
Oral Vaccines ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Viral Antigens ◽  
Mucosal Infection

The most important characteristics regarding the mucosal infection and immune responses against the Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) as well as the current vaccines against coronavirus disease 2019 (COVID-19) in development or use are revised to emphasize the opportunity for lactic acid bacteria (LAB)-based vaccines to offer a valid alternative in the fight against this disease. In addition, this article revises the knowledge on: (a) the cellular and molecular mechanisms involved in the improvement of mucosal antiviral defenses by beneficial Lactiplantibacillus plantarum strains, (b) the systems for the expression of heterologous proteins in L. plantarum and (c) the successful expressions of viral antigens in L. plantarum that were capable of inducing protective immune responses in the gut and the respiratory tract after their oral administration. The ability of L. plantarum to express viral antigens, including the spike protein of SARS-CoV-2 and its capacity to differentially modulate the innate and adaptive immune responses in both the intestinal and respiratory mucosa after its oral administration, indicates the potential of this LAB to be used in the development of a mucosal COVID-19 vaccine.

scholarly journals Engineering Biology to Construct Microbial Chassis for the Production of Difficult-to-Express Proteins

2020 ◽  
Vol 21 (3) ◽  
pp. 990 ◽  
Author(s):  
Kangsan Kim ◽  
Donghui Choe ◽  
Dae-Hee Lee ◽  
Byung-Kwan Cho
Keyword(s):  
Recombinant Protein ◽  
Protein Expression ◽  
Recombinant Proteins ◽  
Heterologous Protein ◽  
Recombinant Protein Expression ◽  
Cost Effective ◽  
Protein Yield ◽  
Heterologous Protein Expression ◽  
Heterologous Proteins ◽  
Expression Pathways

A large proportion of the recombinant proteins manufactured today rely on microbe-based expression systems owing to their relatively simple and cost-effective production schemes. However, several issues in microbial protein expression, including formation of insoluble aggregates, low protein yield, and cell death are still highly recursive and tricky to optimize. These obstacles are usually rooted in the metabolic capacity of the expression host, limitation of cellular translational machineries, or genetic instability. To this end, several microbial strains having precisely designed genomes have been suggested as a way around the recurrent problems in recombinant protein expression. Already, a growing number of prokaryotic chassis strains have been genome-streamlined to attain superior cellular fitness, recombinant protein yield, and stability of the exogenous expression pathways. In this review, we outline challenges associated with heterologous protein expression, some examples of microbial chassis engineered for the production of recombinant proteins, and emerging tools to optimize the expression of heterologous proteins. In particular, we discuss the synthetic biology approaches to design and build and test genome-reduced microbial chassis that carry desirable characteristics for heterologous protein expression.

scholarly journals Resurrecting the ancient glow of the fireflies

2020 ◽  
Vol 6 (49) ◽  
pp. eabc5705
Author(s):  
Y. Oba ◽  
K. Konishi ◽  
D. Yano ◽  
H. Shibata ◽  
D. Kato ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Common Ancestor ◽  
Green Light ◽  
Firefly Luciferase ◽  
Fatty Acyl ◽  
Synthetic Activity ◽  
Spatial Constraint ◽  
Original Function ◽  
Orange Yellow ◽  
The Common

The color of firefly bioluminescence is determined by the structure of luciferase. Firefly luciferase genes have been isolated from more than 30 species, producing light ranging in color from green to orange-yellow. Here, we reconstructed seven ancestral firefly luciferase genes, characterized the enzymatic properties of the recombinant proteins, and determined the crystal structures of the gene from ancestral Lampyridae. Results showed that the synthetic luciferase for the last common firefly ancestor exhibited green light caused by a spatial constraint on the luciferin molecule in enzyme, while fatty acyl-CoA synthetic activity, an original function of firefly luciferase, was diminished in exchange. All known firefly species are bioluminescent in the larvae, with a common ancestor arising approximately 100 million years ago. Combined, our findings propose that, within the mid-Cretaceous forest, the common ancestor of fireflies evolved green light luciferase via trade-off of the original function, which was likely aposematic warning display against nocturnal predation.

scholarly journals Cytoplasmic tail truncation of SARS-CoV-2 Spike protein enhances titer of pseudotyped vectors but masks the effect of the D614G mutation

2021 ◽  
Author(s):  
Hsu-Yu Chen ◽  
Chun Huang ◽  
Lu Tian ◽  
Xiaoli Huang ◽  
Chennan Zhang ◽  
...  
Keyword(s):  
Viral Entry ◽  
High Titer ◽  
Cytoplasmic Tail ◽  
Cell Types ◽  
Spike Protein ◽  
Tangential Flow Filtration ◽  
Tangential Flow ◽  
Protein Functions ◽  
Flow Filtration ◽  
The Impact

The high pathogenicity of SARS-CoV-2 requires it to be handled under biosafety level 3 conditions. Consequently, Spike protein pseudotyped vectors are a useful tool to study viral entry and its inhibition, with retroviral, lentiviral (LV) and vesicular stomatitis virus (VSV) vectors the most commonly used systems. Methods to increase the titer of such vectors commonly include concentration by ultracentrifugation and truncation of the Spike protein cytoplasmic tail. However, limited studies have examined whether such a modification also impacts the protein’s function. Here, we optimized concentration methods for SARS-CoV-2 Spike pseudotyped VSV vectors, finding that tangential flow filtration produced vectors with more consistent titers than ultracentrifugation. We also examined the impact of Spike tail truncation on transduction of various cell types and sensitivity to convalescent serum neutralization. We found that tail truncation increased Spike incorporation into both LV and VSV vectors and resulted in enhanced titers, but had no impact on sensitivity to convalescent serum inhibition. In addition, we analyzed the effect of the D614G mutation, which became a dominant SARS-CoV-2 variant early in the pandemic. Our studies revealed that, similar to the tail truncation, D614G independently increases Spike incorporation and vector titers, but that this effect is masked by also including the cytoplasmic tail truncation. Therefore, the use of full-length Spike protein, combined with tangential flow filtration, is recommended as a method to generate high titer pseudotyped vectors that retain native Spike protein functions.

scholarly journals Structure of a bacterial Rhs effector exported by the type VI secretion system

2021 ◽  
Author(s):  
Patrick Guenther ◽  
Dennis Quentin ◽  
Shehryar Ahmad ◽  
Kartik Sachar ◽  
Christos Gatsogiannis ◽  
...  
Keyword(s):  
Bacterial Cell ◽  
Secretion System ◽  
Effector Proteins ◽  
Protein Export ◽  
Spike Protein ◽  
Gram Negative Bacteria ◽  
Structural Elements ◽  
Type Vi Secretion System ◽  
Gram Negative ◽  
Type Vi Secretion

The type VI secretion system (T6SS) is a widespread protein export apparatus found in Gram-negative bacteria. The majority of T6SSs deliver toxic effector proteins into competitor bacteria. Yet, the structure, function, and activation of many of these effectors remains poorly understood. Here, we present the structures of the T6SS effector RhsA from Pseudomonas protegens and its cognate T6SS spike protein, VgrG1, at 3.3 Å resolution. The structures reveal that the rearrangement hotspot (Rhs) repeats of RhsA assemble into a closed anticlockwise β-barrel spiral similar to that found in bacterial insecticidal Tc toxins and in metazoan teneurin proteins. We find that the C-terminal toxin domain of RhsA is autoproteolytically cleaved but remains inside the Rhs ′cocoon′ where, with the exception of three ordered structural elements, most of the toxin is disordered. The N-terminal ′plug′ domain is unique to T6SS Rhs proteins and resembles a champagne cork that seals the Rhs cocoon at one end while also mediating interactions with VgrG1. Interestingly, this domain is also autoproteolytically cleaved inside the cocoon but remains associated with it. We propose that mechanical force is required to remove the cleaved part of the plug, resulting in the release of the toxin domain as it is delivered into a susceptible bacterial cell by the T6SS.

scholarly journals Assessment of the ptxD gene as a growth and selective marker in Trichoderma atroviride using Pccg6, a novel constitutive promoter

2020 ◽  
Author(s):  
Nohemi Carreras-Villaseñor ◽  
Guillermo Rico-Ruiz ◽  
Ricardo Chavez-Montes ◽  
Lenin Yong-Villalobos ◽  
Jose Fabricio Lopez-Hernandez ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Inducible Promoter ◽  
Sole Source ◽  
Constitutive Promoter ◽  
Heterologous Proteins ◽  
Trichoderma Atroviride ◽  
Trichoderma Species ◽  
Enzyme Preparations ◽  
Chemical Inducers ◽  
Cell Factories

Abstract Background Trichoderma species are among the most effective cell factories to produce recombinant proteins, whose productivity relies on the molecular toolkit and promoters available for the expression of the target protein. Although inducible promoter systems have been developed for producing recombinant proteins in Trichoderma , constitutive promoters are often a desirable alternative. Constitutive promoters are simple to use, do not require external stimuli or chemical inducers to be activated, and lead to purer enzyme preparations. Moreover, most of the promoters for homologous and heterologous expression reported in Trichoderma have been commonly evaluated by directly assessing production of industrial enzymes, requiring optimization of laborious protocols. Results Here we report the identification of P ccg6, a novel Trichoderma atroviride constitutive promoter, that has similar transcriptional strength as that of the commonly used pki1 promoter. P ccg6 displayed conserved arrangements of transcription factor binding sites between promoter sequences of Trichoderma ccg6 orthologues genes, potentially involved in their regulatory properties. The predicted ccg6 -encoded protein potentially belongs to the SPE1/SPI1 protein family and shares high identity with CCG6 orthologue sequences from other fungal species including Trichoderma reesei , Trichoderma virens , Trichoderma asperellum , and lo a lesser extent to that of Neurosposa crassa . We also report the use of the P ccg6 promoter to drive the expression of PTXD, a phosphite oxidoreductase of bacterial origin, which allowed T. atroviride to utilize phosphite as a sole source of phosphorus. We propose ptxD as a growth reporter gene that allows real-time comparison of the functionality of different promoters by monitoring growth of Trichoderma transgenic lines and enzymatic activity of PTXD. Finally, we show thatconstitutive expression of ptxD provided T. atroviride a competitive advantage to outgrow bacterial contaminants when supplied with phosphite as a sole source of phosphorus. Conclusions A new constitutive promoter, ccg6 , for expression of homologous and heterologous proteins has been identified and tested in T. atroviride by expressing PTXD, which resulted in an effective and visible phenotype to evaluate transcriptional activity of sequence promoters. Use of PTXD as a growth marker holds great potential for assessing activity of other promoters and for biotechnological applications as a contamination control system.

scholarly journals Structure of a bacterial Rhs effector exported by the type VI secretion system

2022 ◽  
Vol 18 (1) ◽  
pp. e1010182
Author(s):  
Patrick Günther ◽  
Dennis Quentin ◽  
Shehryar Ahmad ◽  
Kartik Sachar ◽  
Christos Gatsogiannis ◽  
...  
Keyword(s):  
Bacterial Cell ◽  
Secretion System ◽  
Effector Proteins ◽  
Protein Export ◽  
Spike Protein ◽  
Gram Negative Bacteria ◽  
Structural Elements ◽  
Type Vi Secretion System ◽  
Gram Negative ◽  
Type Vi Secretion

The type VI secretion system (T6SS) is a widespread protein export apparatus found in Gram-negative bacteria. The majority of T6SSs deliver toxic effector proteins into competitor bacteria. Yet, the structure, function, and activation of many of these effectors remains poorly understood. Here, we present the structures of the T6SS effector RhsA from Pseudomonas protegens and its cognate T6SS spike protein, VgrG1, at 3.3 Å resolution. The structures reveal that the rearrangement hotspot (Rhs) repeats of RhsA assemble into a closed anticlockwise β-barrel spiral similar to that found in bacterial insecticidal Tc toxins and in metazoan teneurin proteins. We find that the C-terminal toxin domain of RhsA is autoproteolytically cleaved but remains inside the Rhs ‘cocoon’ where, with the exception of three ordered structural elements, most of the toxin is disordered. The N-terminal ‘plug’ domain is unique to T6SS Rhs proteins and resembles a champagne cork that seals the Rhs cocoon at one end while also mediating interactions with VgrG1. Interestingly, this domain is also autoproteolytically cleaved inside the cocoon but remains associated with it. We propose that mechanical force is required to remove the cleaved part of the plug, resulting in the release of the toxin domain as it is delivered into a susceptible bacterial cell by the T6SS.

scholarly journals Fhl1p protein, a positive transcription factor in Pichia pastoris, enhances the expression of recombinant proteins

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Xueyun Zheng ◽  
Yimin Zhang ◽  
Xinying Zhang ◽  
Cheng Li ◽  
Xiaoxiao Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Pichia Pastoris ◽  
Recombinant Proteins ◽  
Recombinant Protein Expression ◽  
Large Subunit ◽  
Protein A ◽  
Methylotrophic Yeast ◽  
Regulation Mechanism ◽  
Heterologous Proteins ◽  
Foreign Proteins

Abstract Background The methylotrophic yeast Pichia pastoris is well-known for the production of a broad spectrum of functional types of heterologous proteins including enzymes, antigens, engineered antibody fragments, and next gen protein scaffolds and many transcription factors are utilized to address the burden caused by the high expression of heterologous proteins. In this article, a novel P. pastoris transcription factor currently annotated as Fhl1p, an activator of ribosome biosynthesis processing, was investigated for promoting the expression of the recombinant proteins. Results The function of Fhl1p of P. pastoris for improving the expression of recombinant proteins was verified in strains expressing phytase, pectinase and mRFP, showing that the productivity was increased by 20–35%. RNA-Seq was used to study the Fhl1p regulation mechanism in detail, confirming Fhl1p involved in the regulation of rRNA processing genes, ribosomal small/large subunit biogenesis genes, Golgi vesicle transport genes, etc., which contributed to boosting the expression of foreign proteins. The overexpressed Fhl1p strain exhibited increases in the polysome and monosome levels, showing improved translation activities. Conclusion This study illustrated that the transcription factor Fhl1p could effectively enhance recombinant protein expression in P. pastoris. Furthermore, we provided the evidence that overexpressed Fhl1p was related to more active translation state.

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