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
Note to TJ-Train students: 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.
###: ###-### [PubMed]
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
(*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 arrangement.
Rossa J, Protze J, Kern C, Piontek A, Günzel D,
Br. J. Pharmacol.
Hülper P, Veszelka S, Walter FR, Wolburg H, Fallier-Becker P,
Blasig IE, Lakomek M, Kugler W, Deli MA (2013) Acute effects of short-chain
alkylglycerols on blood-brain barrier properties of cultured brain endothelial
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
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:
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
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
perfringens enterotoxin and claudin-3.