DFG Research Training Group "TJ-Train" (GRK 2318)
Tight junctions and their proteins
Molecular features and actions in health and disease
Prof. Dr. Dominik Müller
Klinik für Pädiatrie m.S. Nephrologie, Charité - Universitätsmedizin Berlin,
The magnesiome, an integrative view of magnesium regulation
Background: Knowledge about renal physiology and pathophysiology of Mg2+
handling has been broadened by the identification of mutations in humans causing Mg2+-related disorders as well as by the generation of different mouse models of
Hypothesis: We hypothesize that maintaining Mg2+ homeostasis in the kidney is
regulated by para- and transcellular mechanisms acting tightly concerted via a crosstalk between the TAL and the DCT thereby integrating paracellular (tight junction) and transcellular pathways.
Aims: The project aims to elucidate local, regional and global mechanisms of renal Mg2+ regulation, establishing a network of Mg2+
regulation. Different sources of mouse models with normal and disordered Mg2+
regulation will be used (RNA, protein) to identify differential regulation.
Methods: In this project, we will use our mouse models (deficient in Cldn16, Cldn10, Cldn10/16 and recently
generated, Cnnm2) together with patient data to generate an integra-tive view on magnesium homeostasis, the ‚magnesiome‘. To reach this goal, we will pheno- and genotype the mentioned mouse
models, which display hypo-, normo- or even hy-permagnesemia. Analysis will include RNAseq and ChiP analysis. Further, we aim to identify and characterize proteins interacting with claudin-16,
claudin-10, claudin-10/-16 and Cnnm2 by protein affinity purification and SILAC (stable isotope labelling by amino acids in cell culture). Subsequently, patients
of our large cohort with so far unexplained Mg2+
deficiency will be screened for mutations in the genes or transcripts of the identified proteins.
Thesis project: Upon completion of this project, the successful candidate will finally be able to conduct
phenotyping and genotyping with special emphasis on renal homeostasis of mouse models. RNASeq and CHiP analysis will be performed as well as Proteomic studies. The data generated will then be
analysed and assembled by means of bioinformatics tools in order to provide common pathways of Mg2+ homeostasis but also identify crucial variations in specific
Suggested reading: See Project-related publications,
especially Refs. 4, 5, 7, and 11
PhD doctoral student
Seker M, Fernandez-Rodriguez C, Martinez-Cruz LA, Müller D (2019) Mouse models of human claudin-associated disorders:
benefits and limitations. Int. J. Mol. Sci. 20(21): 5504 (19 pages)
(°IF 4.2) [PDF] [WebPage]
a paper is not accessible, please mail to
Corral-Rodríguez MA, Stuiver M, Abascal-Palacios G, Diercks T, Oyenarte I, Ereño-Orbea J, Ibáñez De Opakua A, Blanco FJ, Encinar
JA, Spiwok V, Terashima H, Accardi A, Müller D, Martinez-Cruz LA (2014) Nucleotide binding triggers a conformational change of the CBS module of the magnesium transporter CNNM2 from a
twisted towards a flat structure.
Kooij G, Kopplin K, Blasig R, Stuiver M, Koning N, Goverse G, van der Pol SM, van Het Hof B, Gollasch M, Drexhage JA, Reijerkerk A,
Meij IC, Mebius R, Willnow TE, Müller D, Blasig IE, de Vries HE (2014) Disturbed function of the blood-cerebrospinal fluid barrier aggravates neuro-inflammation.
de Baaij JH, Stuiver M, Meij IC, Lainez S, Kopplin K, Venselaar H,
Müller D, Bindels RJ, Hoenderop JG (2012) Membrane topology and intracellular processing of cyclin M2 (CNNM2).
Proc. Natl. Acad. Sci. USA
Breiderhoff T, Himmerkus N, Stuiver M, Mutig K, Will C, Meij IC, Bachmann S, Bleich M, Willnow TE, Müller D (2012)
Deletion of claudin-10 (Cldn10) in the thick ascending limb impairs paracellular sodium permeability and leads to hypermagnesemia and nephrocalcinosis.
handling, is mutated in dominant hypomagnesemia.
Am. J. Hum. Genet.
Stuiver M, Lainez S, Will C, Terryn S, Günzel D, Debaix H, Sommer K, Kopplin K, Thumfart J, Kampik NB, Querfeld U, Willnow TE,
Němec V, Wagner CA, Hoenderop JG, Devuyst O, Knoers NV, Bindels RJ, Meij IC, Müller D (2011) CNNM2, encoding a basolateral protein required for renal Mg
Biochim. Biophys. Acta
Milatz S, Krug SM, Rosenthal R, Günzel D, Müller D, Schulzke JD, Amasheh S, Fromm M (2010) Claudin-3 acts as a sealing
component of the tight junction for ions of either charge and uncharged solutes.
identifies extra- and intrarenal compensatory mechanisms of Ca2+
wasting. Am. J. Physiol. Renal Physiol.
Will C, Breiderhoff T, Thumfart J, Stuiver M, Kopplin K, Sommer K, Günzel D, Querfeld U, Meij IC, Shan Q, Bleich M, Willnow TE,
Müller D (2010) Targeted deletion of murine
J. Cell Sci.
Günzel D, Stuiver M, Kausalya PJ, Haisch L, Hunziker W, Krug S, Meij IC, Fromm M, Müller D (2009) Identification and
characterization of six novel claudin-10 splice variants.
Am. J. Physiol. Renal Physiol.
Thumfart J, Jung S, Amasheh S, Krämer S, Peters H, Sommer K, Biber J, Murer H, Meij IC, Querfeld U, Wagner CA, Müller D
(2008) Magnesium stimulates renal phosphate reabsorption.
Am. J. Hum. Genet.
Müller D, Kausalya PJ, Claverie-Martin F, Meij IC, Eggert P, Garcia-Nieto V, Hunziker W (2003) A novel mutation in
claudin-16 associated with childhood hypercalciuria abolishes binding to ZO-1 and leads to lysosomal mistargeting.
Jeroen H. F. de Baaij, Joost G. J. Hoenderop, René J. M. Bindels (2014) Magnesium in man: Implications for health
Physiol. Rev. 95: 1-46