TY  - JOUR
A1  - Norrmen, Camilla
A1  - Figlia, Gianluca
A1  - Lebrun-Julien, Frederic
A1  - Pereira, Jorge A.
A1  - Trötzmüller, Martin
A1  - Köfeler, Harald C.
A1  - Rantanen, Ville
A1  - Wessig, Carsten
A1  - van Deijk, Anne-Lieke F.
A1  - Smit, August B.
A1  - Verheijen, Mark H. G.
A1  - Rüegg, Markus A.
A1  - Hall, Michael N.
A1  - Suter, Ueli
T1  - mTORC1 Controls PNS Myelination along the mTORC1-RXR gamma-SREBP-Lipid Biosynthesis Axis in Schwann Cells
JF  - Cell Reports
N2  - Myelin formation during peripheral nervous system (PNS) development, and reformation after injury and in disease, requires multiple intrinsic and extrinsic signals. Akt/mTOR signaling has emerged as a major player involved, but the molecular mechanisms and downstream effectors are virtually unknown. Here, we have used Schwann-cell-specific conditional gene ablation of raptor and rictor, which encode essential components of the mTOR complexes 1 (mTORC1) and 2 (mTORC2), respectively, to demonstrate that mTORC1 controls PNS myelination during development. In this process, mTORC1 regulates lipid biosynthesis via sterol regulatory element-binding proteins (SREBPs). This course of action is mediated by the nuclear receptor RXRg, which transcriptionally regulates SREBP1c downstream of mTORC1. Absence of mTORC1 causes delayed myelination initiation as well as hypomyelination, together with abnormal lipid composition and decreased nerve conduction velocity. Thus, we have identified the mTORC1-RXR gamma-SREBP axis controlling lipid biosynthesis as a major contributor to proper peripheral nerve function.
KW  - axonal integrity
KW  - peripheral nervous-system
KW  - COMPLEX 1
KW  - rat hepatocytes
KW  - SREBP
KW  - mice
KW  - growth
KW  - protein
KW  - element
KW  - CNS Myelination
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114847
SN  - 2211-1247
VL  - 9
IS  - 2
ER  - 
TY  - JOUR
A1  - Dietz, Mariana S.
A1  - Hasse, Daniel
A1  - Ferraris, Davide M.
A1  - Göhler, Antonia
A1  - Niemann, Hartmut H.
A1  - Heilemann, Mike
T1  - Single-molecule photobleaching reveals increased MET receptor dimerization upon ligand binding in intact cells
JF  - BMC Biophysics
N2  - Background: The human receptor tyrosine kinase MET and its ligand hepatocyte growth factor/scatter factor are essential during embryonic development and play an important role during cancer metastasis and tissue regeneration. In addition, it was found that MET is also relevant for infectious diseases and is the target of different bacteria, amongst them Listeria monocytogenes that induces bacterial uptake through the surface protein internalin B. Binding of ligand to the MET receptor is proposed to lead to receptor dimerization. However, it is also discussed whether preformed MET dimers exist on the cell membrane. 
Results: To address these issues we used single-molecule fluorescence microscopy techniques. Our photobleaching experiments show that MET exists in dimers on the membrane of cells in the absence of ligand and that the proportion of MET dimers increases significantly upon ligand binding. 
Conclusions: Our results indicate that partially preformed MET dimers may play a role in ligand binding or MET signaling. The addition of the bacterial ligand internalin B leads to an increase of MET dimers which is in agreement with the model of ligand-induced dimerization of receptor tyrosine kinases.
KW  - single-molecule photobleaching
KW  - fluorescence correlation spectroscopy
KW  - fluorescence
KW  - EGF receptor
KW  - rat hepatocytes
KW  - structural insights
KW  - Scatter factor
KW  - SEMA domain
KW  - hepatocyte-growth-factor
KW  - invasion protein-INLB
KW  - listeria-monocytogenes
KW  - tyrosine kinase
KW  - living cells
KW  - dimerization
KW  - MET receptor
KW  - Signal transduction
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-121835
SN  - 2046-1682
VL  - 6
IS  - 6
ER  -