TY  - JOUR
A1  - Murakawa, Yasuhiro
A1  - Hinz, Michael
A1  - Mothes, Janina
A1  - Schuetz, Anja
A1  - Uhl, Michael
A1  - Wyler, Emanuel
A1  - Yasuda, Tomoharu
A1  - Mastrobuoni, Guido
A1  - Friedel, Caroline C.
A1  - Dölken, Lars
A1  - Kempa, Stefan
A1  - Schmidt-Supprian, Marc
A1  - Blüthgen, Nils
A1  - Backofen, Rolf
A1  - Heinemann, Udo
A1  - Wolf, Jana
A1  - Scheidereit, Claus
A1  - Landthaler, Markus
T1  - RC3H1 post-transcriptionally regulates A20 mRNA and modulates the activity of the IKK/NF-\(\kappa\)B pathway
JF  - Nature Communications
N2  - The RNA-binding protein RC3H1 (also known as ROQUIN) promotes TNF\(\alpha\) mRNA decay via a 3'UTR constitutive decay element (CDE). Here we applied PAR-CLIP to human RC3H1 to identify ~3,800 mRNA targets with >16,000 binding sites. A large number of sites are distinct from the consensus CDE and revealed a structure-sequence motif with U-rich sequences embedded in hairpins. RC3H1 binds preferentially short-lived and DNA damage-induced mRNAs, indicating a role of this RNA-binding protein in the post-transcriptional regulation of the DNA damage response. Intriguingly, RC3H1 affects expression of the NF-\(\kappa\)B pathway regulators such as I\(\kappa\)B\(\alpha\) and A20. RC3H1 uses ROQ and Zn-finger domains to contact a binding site in the A20 3'UTR, demonstrating a not yet recognized mode of RC3H1 binding. Knockdown of RC3H1 resulted in increased A20 protein expression, thereby interfering with I\(\kappa\)B kinase and NF-\(\kappa\)B activities, demonstrating that RC3H1 can modulate the activity of the IKK/NF-\(\kappa\)B pathway.
KW  - large gene lists
KW  - decay
KW  - identification
KW  - stress
KW  - binding protein
KW  - RQQ domain
KW  - autoimmunity
KW  - complex
KW  - degradation
KW  - motifs
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151596
VL  - 6
IS  - 7367
ER  - 
TY  - JOUR
A1  - Hafner, Christian
A1  - Houben, Roland
A1  - Baeurle, Anne
A1  - Ritter, Cathrin
A1  - Schrama, David
A1  - Landthaler, Michael
A1  - Becker, Jürgen C.
T1  - Activation of the PI3K/AKT Pathway in Merkel Cell Carcinoma
JF  - PLoS One
N2  - Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with an increasing incidence. The understanding of the molecular carcinogenesis of MCC is limited. Here, we scrutinized the PI3K/AKT pathway, one of the major pathways activated in human cancer, in MCC. Immunohistochemical analysis of 41 tumor tissues and 9 MCC cell lines revealed high levels of AKT phosphorylation at threonine 308 in 88% of samples. Notably, the AKT phosphorylation was not correlated with the presence or absence of the Merkel cell polyoma virus (MCV). Accordingly, knock-down of the large and small T antigen by shRNA in MCV positive MCC cells did not affect phosphorylation of AKT. We also analyzed 46 MCC samples for activating PIK3CA and AKT1 mutations. Oncogenic PIK3CA mutations were found in 2/46 (4%) MCCs whereas mutations in exon 4 of AKT1 were absent. MCC cell lines demonstrated a high sensitivity towards the PI3K inhibitor LY-294002. This finding together with our observation that the PI3K/AKT pathway is activated in the majority of human MCCs identifies PI3K/AKT as a potential new therapeutic target for MCC patients.
KW  - rare
KW  - T-antigen
KW  - PIK3CA mutations
KW  - squamous cell
KW  - melanoma
KW  - polymavirus
KW  - cancer
KW  - tumors
KW  - akt
KW  - expression
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131398
VL  - 7
IS  - 2
ER  -