DFG Research Training Group "TJ-Train" (GRK 2318)
Tight junctions and their proteins
Molecular features and actions in health and disease
Clostridium perfringens enterotoxin (CPE) causes one of the most common food borne illnesses. CPE binds to tight junction
(TJ) proteins (e.g. claudin-3 and -4) and subsequently forms pores in the membrane leading to damage of epithelial cells. Due to its cytotoxicity, CPE is used for targeting of
claudin-overexpressing tumor cells. In contrast, the c-terminal domain cCPE of CPE is non-toxic and contains the claudin binding domain. cCPE is used as a TJ modulator to increase paracellular
drug delivery. Previously, we elucidated in structure-based studies the molecular mechanism of the CPE-claudin interaction and designed CPE- or cCPE-variants with shifted claudin
subtypespecificity (e.g. binding to claudin-1 or -5).
Aim of this project are expanded structure-function studies to design and to test variants of cCPE and CPE as claudin subtype-specific and in turn tissue-specific biologicals for (i)
improved drug delivery by TJ-modulation, (ii) molecular diagnosis or (iii) cytotoxic treatment of carcinomas.
Methods: Molecular modelling, site-directed mutagenesis, expression and purification of recombinant proteins, protein-protein interaction assays, cell culture of differentiated epithelial
and carcinoma cells, immunocytochemistry and confocal microscopy. Activity of cCPE- and CPE-variants will be tested by measurements of transepithelial resistance and paracellular solute
permeability as well as imaging and cytotoxicity assays with cell lines and in vivo xenotransplant tumor models.
PhD doctoral student
If a paper is
not accessible, please mail to
Baumholtz AI, Simard A, Nikolopoulou E, Oosenbrug M, Collins MM, Piontek A, Krause G, Piontek J, Greene NDE, Ryan AK (2017) Claudins are essential for cell shape changes and
convergent extension movements during neural tube closure.
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Liao Z, Yang Z, Piontek A, Eichner M, Krause G, Li L,
Piontek J, Zhang J (2016) Specific binding of a mutated fragment of Clostridium perfringens
enterotoxin to endothelial claudin-5 and its modulation of cerebral vascular permeability.
(*shared last authorship) (2015) Directed structural modification of Clostridium perfringens enterotoxin to enhance binding to claudin-5.
Cell. Mol. Life Sci.
Protze J, Eichner M, Piontek A, Dinter S, Rossa J, Blecharz KG, Vajkoczy P, Piontek J
Zhang J, Ni C, Yang Z, Piontek A, Chen H, Wang S, Fan Y, Qin Z,
Piontek J (2015) Specific binding of Clostridium perfringens enterotoxin fragment to claudin-b and modulation of zebrafish epidermal barrier.
(*shared last authorship) (2014) Molecular and structural transmembrane determinants critical for embedding claudin-5 into tight junctions reveal a distinct four-helix bundle
Rossa J, Protze J, Kern C, Piontek A, Günzel D,
Br. J. Pharmacol.
Hülper P, Veszelka S, Walter FR, Wolburg H, Fallier-Becker P,
Piontek J, Blasig IE, Lakomek M, Kugler W, Deli MA (2013) Acute effects of short-chain alkylglycerols on blood-brain barrier properties of cultured brain endothelial cells.
Veshnyakova A*, Piontek J* (*shared first authorship), Protze J, Waziri N, Heise I, Krause G (2012) Mechanism of
Clostridium perfringens enterotoxin interaction with claudin-3/-4 protein suggests structural modifications of the toxin to target specific claudin.
Walther W, Petkov S, Kuvardina ON, Aumann J, Kobelt D, Fichtner I, Lemm M,
Piontek J, Blasig IE, Stein U, Schlag PM (2012) Novel Clostridium perfringens
enterotoxin suicide gene therapy for selective treatment of claudin-3 and -4 overexpressing tumors.
Piehl C*, Piontek J* (*shared first authorship), Cording J, Wolburg H, Blasig IE (2010) Participation of the second extracellular loop
of claudin-5 in paracellular tightening against ions, small and large molecules.
Cell. Mol. Life Sci. 67: 2131-2140
BMC Mol. Biol.
10: 61 (printed pages 1-8)
Lohrberg D, Schümann M, Piontek J, Winkler L, Krause E, Blasig IE, Haseloff RF (2009) A proteomic approach for identification of tight
junction-associated proteins, based on claudin affinity to Clostridium perfringens enterotoxin.
J. Biol. Chem.
Winkler L, Wenzel A, Gehring C, Piehl C, Mueller SL,
Krause G, Blasig IE,
Piontek J (2009) Molecular determinants of the interaction between
Clostridium perfringens enterotoxin and claudin-3.