TY  - JOUR
A1  - Degenkolbe, Elisa
A1  - König, Jana
A1  - Zimmer, Julia
A1  - Walther, Maria
A1  - Reißner, Carsten
A1  - Nickel, Joachim
A1  - Plöger, Frank
A1  - Raspopovic, Jelena
A1  - Sharpe, James
A1  - Dathe, Katharina
A1  - Hecht, Jacqueline T.
A1  - Mundlos, Stefan
A1  - Doelken, Sandra C.
A1  - Seemann, Petra
T1  - A GDF5 Point Mutation Strikes Twice - Causing BDA1 and SYNS2
JF  - PLOS Genetics
N2  - Growth and Differentiation Factor 5 (GDF5) is a secreted growth factor that belongs to the Bone Morphogenetic Protein (BMP) family and plays a pivotal role during limb development. GDF5 is a susceptibility gene for osteoarthritis (OA) and mutations in GDF5 are associated with a wide variety of skeletal malformations ranging from complex syndromes such as acromesomelic chondrodysplasias to isolated forms of brachydactylies or multiple synostoses syndrome 2 (SYNS2). Here, we report on a family with an autosomal dominant inherited combination of SYNS2 and additional brachydactyly type A1 (BDA1) caused by a single point mutation in GDF5 (p.W414R). Functional studies, including chondrogenesis assays with primary mesenchymal cells, luciferase reporter gene assays and Surface Plasmon Resonance analysis, of the GDF5 W-414R variant in comparison to other GDF5 mutations associated with isolated BDA1 (p.R399C) or SYNS2 (p.E491K) revealed a dual pathomechanism characterized by a gain-and loss-of-function at the same time. On the one hand insensitivity to the main GDF5 antagonist NOGGIN (NOG) leads to a GDF5 gain of function and subsequent SYNS2 phenotype. Whereas on the other hand, a reduced signaling activity, specifically via the BMP receptor type IA (BMPR1A), is likely responsible for the BDA1 phenotype. These results demonstrate that one mutation in the overlapping interface of antagonist and receptor binding site in GDF5 can lead to a GDF5 variant with pathophysiological relevance for both, BDA1 and SYNS2 development. Consequently, our study assembles another part of the molecular puzzle of how loss and gain of function mutations in GDF5 affect bone development in hands and feet resulting in specific types of brachydactyly and SYNS2. These novel insights into the biology of GDF5 might also provide further clues on the pathophysiology of OA.
KW  - dominant-negative mutatio
KW  - morphogenetic protein receptors
KW  - brachtydacyly type A2
KW  - BMP
KW  - gene encoding noggin
KW  - growth factor beta
KW  - signal tranduction
KW  - molecular mechanism
KW  - crystal-structure
KW  - differentiation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127556
SN  - 1553-7404
VL  - 9
IS  - 10
ER  - 
TY  - JOUR
A1  - Diestel, Uschi
A1  - Resch, Marcus
A1  - Meinhardt, Kathrin
A1  - Weiler, Sigrid
A1  - Hellmann, Tina V.
A1  - Mueller, Thomas D.
A1  - Nickel, Joachim
A1  - Eichler, Jutta
A1  - Muller, Yves A.
T1  - Identification of a Novel TGF-beta-Binding Site in the Zona Pellucida C-terminal (ZP-C) Domain of TGF-\(\beta\)-Receptor-3 (TGFR-3)
JF  - PLoS ONE
N2  - The zona pellucida (ZP) domain is present in extracellular proteins such as the zona pellucida proteins and tectorins and participates in the formation of polymeric protein networks. However, the ZP domain also occurs in the cytokine signaling co-receptor transforming growth factor beta (TGF-\(\beta\)) receptor type 3 (TGFR-3, also known as betaglycan) where it contributes to cytokine ligand recognition. Currently it is unclear how the ZP domain architecture enables this dual functionality. Here, we identify a novel major TGF-beta-binding site in the FG loop of the C-terminal subdomain of the murine TGFR-3 ZP domain (ZP-C) using protein crystallography, limited proteolysis experiments, surface plasmon resonance measurements and synthetic peptides. In the murine 2.7 angstrom crystal structure that we are presenting here, the FG-loop is disordered, however, well-ordered in a recently reported homologous rat ZP-C structure. Surprisingly, the adjacent external hydrophobic patch (EHP) segment is registered differently in the rat and murine structures suggesting that this segment only loosely associates with the remaining ZP-C fold. Such a flexible and temporarily-modulated association of the EHP segment with the ZP domain has been proposed to control the polymerization of ZP domain-containing proteins. Our findings suggest that this flexibility also extends to the ZP domain of TGFR-3 and might facilitate co-receptor ligand interaction and presentation via the adjacent FG-loop. This hints that a similar C-terminal region of the ZP domain architecture possibly regulates both the polymerization of extracellular matrix proteins and cytokine ligand recognition of TGFR-3.
KW  - coreceptor
KW  - receptor type III
KW  - growth factor beta
KW  - ligand binding
KW  - betaglycan
KW  - proteins
KW  - mutagenesis
KW  - polymerization
KW  - glycoprotein
KW  - superfamily
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130904
VL  - 8
IS  - 6
ER  -