Next Article in Journal
Clinical Utility of the Adrenocorticotropin Stimulation Test with/without Dexamethasone Suppression for Definitive and Subtype Diagnosis of Primary Aldosteronism
Previous Article in Journal
Clock Genes and Altered Sleep–Wake Rhythms: Their Role in the Development of Psychiatric Disorders
Previous Article in Special Issue
Unconventional Secretion of Heat Shock Proteins in Cancer
Article Menu
Issue 5 (May) cover image

Export Article

Open AccessArticle
Int. J. Mol. Sci. 2017, 18(5), 937;

Applying Unconventional Secretion in Ustilago maydis for the Export of Functional Nanobodies

Institute for Microbiology, Cluster for Excellence on Plant Sciences, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
Bioeconomy Science Center (BioSC), c/o Forschungszentrum Jülich, 52425 Jülich, Germany
Department of Biotechnology (DBT), Muthgasse 18, 1190 Vienna, Austria
Author to whom correspondence should be addressed.
Academic Editors: Gian-Pietro Di Sansebastiano and Antonio Gaballo
Received: 28 February 2017 / Revised: 21 April 2017 / Accepted: 24 April 2017 / Published: 29 April 2017
(This article belongs to the Special Issue Unconventional Proteins and Membranes Traffic)
Full-Text   |   PDF [3538 KB, uploaded 29 April 2017]   |  


Exploiting secretory pathways for production of heterologous proteins is highly advantageous with respect to efficient downstream processing. In eukaryotic systems the vast majority of heterologous proteins for biotechnological application is exported via the canonical endoplasmic reticulum–Golgi pathway. In the endomembrane system target proteins are often glycosylated and may thus be modified with foreign glycan patterns. This can be destructive for their activity or cause immune reactions against therapeutic proteins. Hence, using unconventional secretion for protein expression is an attractive alternative. In the fungal model Ustilago maydis, chitinase Cts1 is secreted via an unconventional pathway connected to cell separation which can be used to co-export heterologous proteins. Here, we apply this mechanism for the production of nanobodies. First, we achieved expression and unconventional secretion of a functional nanobody directed against green fluorescent protein (Gfp). Second, we found that Cts1 binds to chitin and that this feature can be applied to generate a Gfp-trap. Thus, we demonstrated the dual use of Cts1 serving both as export vehicle and as purification tag. Finally, we established and optimized the production of a nanobody against botulinum toxin A and hence describe the first pharmaceutically relevant target exported by Cts1-mediated unconventional secretion. View Full-Text
Keywords: Ustilago maydis; unconventional secretion; nanobody; chitinase; botulinum toxin A Ustilago maydis; unconventional secretion; nanobody; chitinase; botulinum toxin A

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Terfrüchte, M.; Reindl, M.; Jankowski, S.; Sarkari, P.; Feldbrügge, M.; Schipper, K. Applying Unconventional Secretion in Ustilago maydis for the Export of Functional Nanobodies. Int. J. Mol. Sci. 2017, 18, 937.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top