Designer Glycans, live at PCWB2021

The Designer Glycans lab is represented by four members (Catalin, Annika, Bo, and Madalen) at the 7th International Conference on Plant Cell Wall Biology (PCWB2021). Originally scheduled to take place in Sapporo, Japan last year, this meeting is now in a digital format to accommodate a global audience from June 27 to July 1, 2021.

We are happy to see many international colleagues from the plant cell wall biology field and present our latest unpublished results in two posters (Bo and Annika) and one talk (Madalen) during this exciting meeting.

Annika presents our latest finding on the biodiversity of heteromannan-producing enzymes from across the plant kingdom.

To prioritize enzymes to be characterized in planta, Annika is leveraging the power of our yeast expression system for heteromannan production: https://doi.org/10.1073/pnas.1814003116 and https://doi.org/10.3390/plants8110516

Madalen will talk about the modular engineering of cellulose-synthase like enzymes and the development of new carbohydrate-binding probes for non-invasive heteromannan detection.

Novel probes are required to monitor the dynamics of plant polysaccharides in a high-throughput. Limitations of current tools were discussed in this review: https://doi.org/10.1104/pp.17.01776

Bo present novel microtubule-related players that modulate of cellulose deposition around the surface of Arabidopsis seeds. This projects stems from a collaboration with Katharina Bürstenbinder at IPB Halle.

The new mutants are reminiscent of the published trm4 seed phenotypes, which Bo and Catalin previously worked on: https://doi.org/10.1111/nph.15442

We will look forward to many engaging discussions during PCWB2021.

Building modular hemicellulose synthases, now out in Biotechnology for Biofuels

We are happy to announce the publication of our work on modular hemicellulose production in Biotechnology for Biofuels, a leading (open-access!) journal for advancing the biological production of fuels, chemicals, and biomaterials. Here, we describe how enzymes from the cellulose synthase-like superfamily (found throughout the plant kingdom) can be assembled as modular parts (akin to LEGO bricks) to modulate their function and effects on eukaryotic cell growth.

Fig. 1

Reference:

Robert, M., Waldhauer, J., Stritt, F. et al. Modular biosynthesis of plant hemicellulose and its impact on yeast cells. Biotechnol Biofuels 14, 140 (2021). https://doi.org/10.1186/s13068-021-01985-z

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. 

Previously the article was available on bioRxiv preprint server: https://doi.org/10.1101/2021.04.20.440611

Funding for PhD and Postdoc Available

Two exciting career opportunities are available in the Designer Glycans group starting February 2022. The PhD and postdoctoral positions are fully funded and offer outstanding benefits. Our ambitious independent junior research group has state-of-the-art facilities for carbohydrate analysis, cell imaging and plant cultivation. We are looking for candidates who are interested in synthetic biology, plant cell walls and/or engineered living materials. Both positions will build upon our recent findings, such as:


Voiniciuc et al., 2019, PNAS https://doi.org/10.1073/pnas.1814003116

Yang et al., 2020, New Phytolhttps://doi.org/10.1111/nph.17056

Robert et al., 2021, bioRxivhttps://doi.org/10.1101/2021.04.20.440611

Full descriptions of the positions and how to apply can be downloaded below.

Review of applications begins immediately and will continue until each position is filled. Inquiries can be sent to Catalin.Voiniciuc[at]ipb-halle.de

Update to our bioRxiv preprint

We significantly revised our preprint on the modular biosynthesis of plant heteromannans and uploaded the new version to bioRxiv.

Full-text: https://www.biorxiv.org/content/10.1101/2021.04.20.440611v2.full

Original post

New preprint on yeast bioengineering to produce modular plant hemicellulose

Despite rising interest in the engineering of polysaccharide-based biomaterials, relatively little is known about how plant hemicelluloses can be built and tailored in non-plant cell factories. Pichia pastoris is a promising host to study cellulose synthase-like A (CSLA; heteromannan synthases) and CSLC (xyloglucan synthase) activities but the functions of specific protein motifs and the impactContinue reading “New preprint on yeast bioengineering to produce modular plant hemicellulose”

New preprint on yeast bioengineering to produce modular plant hemicellulose

Despite rising interest in the engineering of polysaccharide-based biomaterials, relatively little is known about how plant hemicelluloses can be built and tailored in non-plant cell factories. Pichia pastoris is a promising host to study cellulose synthase-like A (CSLA; heteromannan synthases) and CSLC (xyloglucan synthase) activities but the functions of specific protein motifs and the impact of their products remain unclear. Here, we used a Golden Gate-based system to assemble chimeric CSL enzymes and optimize yeast cultivation to rapidly produce hemicellulose in mg scale.

Part of Figure 1: Schematic of two plant CSLA enzymes, whose protein domains were exchanged in this study to generate a series of chimeric enzymes.

Interestingly, prolonged expression of a konjac AkCSLA3 glucomannan synthase was toxic to yeast cells, but this impairment was restored by swapping its C-terminal region with that of an Arabidopsis AtCSLA2 mannan synthase. Additional chimeras exceeded the yields of the native enzymes. Overall, cell size was increased or decreased depending on the CSLA sequences used.

Part of Figure 2. Mannose (Man) content, representing insoluble heteromannans, is significantly increased in three of the eight chimeric enzymes tested compared to the parental controls.

Part of Figure 5: The growth rate of the AkCSLA3 yeast strain is significantly lower than the rest. Prolonged glucomannan synthase expression also reduces cell integrity, evidenced by the uptake of the trypan blue strain (panel b), and size.

Yeast containing plant-like polysaccharides could be viewed as tunable biological capsules for further metabolic engineering studies. Sensitive macromolecules such as therapeutic proteins can be protected by encapsulation in non-toxic plant polysaccharides and Pichia cells are attractive hosts for recombinant protein production. Therefore, our strategy provides basic insight into matrix polysaccharide biosynthesis and could also be used to encapsulate valuable cargo.

Publication:

M Robert, J Waldhauer, F Stritt, B Yang, M Pauly, C Voiniciuc (2021) Rapid, modular biosynthesis of plant hemicellulose and its impact on yeast cells bioRxiv, https://doi.org/10.1101/2021.04.20.44061