TY  - JOUR
A1  - Thomas, Sarah
A1  - Fiebig, Juliane E.
A1  - Kuhn, Eva-Maria
A1  - Mayer, Dominik S.
A1  - Filbeck, Sebastian
A1  - Schmitz, Werner
A1  - Krischke, Markus
A1  - Gropp, Roswitha
A1  - Mueller, Thomas D.
T1  - Design of glycoengineered IL-4 antagonists employing chemical and biosynthetic glycosylation
JF  - ACS Omega
N2  - Interleukin-4 (IL-4) plays a key role in atopic diseases. It coordinates T-helper cell differentiation to subtype 2, thereby directing defense toward humoral immunity. Together with Interleukin-13, IL-4 further induces immunoglobulin class switch to IgE. Antibodies of this type activate mast cells and basophilic and eosinophilic granulocytes, which release pro-inflammatory mediators accounting for the typical symptoms of atopic diseases. IL-4 and IL-13 are thus major targets for pharmaceutical intervention strategies to treat atopic diseases. Besides neutralizing antibodies against IL-4, IL-13, or its receptors, IL-4 antagonists can present valuable alternatives. Pitrakinra, an Escherichia coli-derived IL-4 antagonist, has been evaluated in clinical trials for asthma treatment in the past; however, deficits such as short serum lifetime and potential immunogenicity among others stopped further development. To overcome such deficits, PEGylation of therapeutically important proteins has been used to increase the lifetime and proteolytic stability. As an alternative, glycoengineering is an emerging strategy used to improve pharmacokinetics of protein therapeutics. In this study, we have established different strategies to attach glycan moieties to defined positions in IL-4. Different chemical attachment strategies employing thiol chemistry were used to attach a glucose molecule at amino acid position 121, thereby converting IL-4 into a highly effective antagonist. To enhance the proteolytic stability of this IL-4 antagonist, additional glycan structures were introduced by glycoengineering utilizing eucaryotic expression. IL-4 antagonists with a combination of chemical and biosynthetic glycoengineering could be useful as therapeutic alternatives to IL-4 neutralizing antibodies already used to treat atopic diseases.
KW  - Interleukin-4 (IL-4)
KW  - atopic diseases
KW  - IL-4 antagonists
KW  - glycoengineering
KW  - biosynthetic glycosylation
KW  - chemical glycosylation
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350278
SN  - 2470-1343
VL  - 8
IS  - 28
ER  - 
TY  - JOUR
A1  - Lehmann, Julian
A1  - Jørgensen, Morten E.
A1  - Fratz, Stefanie
A1  - Müller, Heike M.
A1  - Kusch, Jana
A1  - Scherzer, Sönke
A1  - Navarro-Retamal, Carlos
A1  - Mayer, Dominik
A1  - Böhm, Jennifer
A1  - Konrad, Kai R.
A1  - Terpitz, Ulrich
A1  - Dreyer, Ingo
A1  - Mueller, Thomas D.
A1  - Sauer, Markus
A1  - Hedrich, Rainer
A1  - Geiger, Dietmar
A1  - Maierhofer, Tobias
T1  - Acidosis-induced activation of anion channel SLAH3 in the flooding-related stress response of Arabidopsis
JF  - Current Biology
N2  - Plants, as sessile organisms, gained the ability to sense and respond to biotic and abiotic stressors to survive severe changes in their environments. The change in our climate comes with extreme dry periods but also episodes of flooding. The latter stress condition causes anaerobiosis-triggered cytosolic acidosis and impairs plant function. The molecular mechanism that enables plant cells to sense acidity and convey this signal via membrane depolarization was previously unknown. Here, we show that acidosis-induced anion efflux from Arabidopsis (Arabidopsis thaliana) roots is dependent on the S-type anion channel AtSLAH3. Heterologous expression of SLAH3 in Xenopus oocytes revealed that the anion channel is directly activated by a small, physiological drop in cytosolic pH. Acidosis-triggered activation of SLAH3 is mediated by protonation of histidine 330 and 454. Super-resolution microscopy analysis showed that the increase in cellular proton concentration switches SLAH3 from an electrically silent channel dimer into its active monomeric form. Our results show that, upon acidification, protons directly switch SLAH3 to its open configuration, bypassing kinase-dependent activation. Moreover, under flooding conditions, the stress response of Arabidopsis wild-type (WT) plants was significantly higher compared to SLAH3 loss-of-function mutants. Our genetic evidence of SLAH3 pH sensor function may guide the development of crop varieties with improved stress tolerance.
KW  - SLAH3
KW  - S-type anion channel
KW  - hypoxia
KW  - pH
KW  - cytosolic acidification
KW  - flooding
KW  - PALM
KW  - stoichiometry
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-363320
VL  - 31
ER  -