TY  - JOUR
A1  - Frank, Daniel O.
A1  - Dengjel, Jörn
A1  - Wilfling, Florian
A1  - Kozjak-Pavlovic, Vera
A1  - Häcker, Georg
A1  - Weber, Arnim
T1  - The Pro-Apoptotic BH3-Only Protein Bim Interacts with Components of the Translocase of the Outer Mitochondrial Membrane (TOM)
JF  - PLoS ONE
N2  - The pro-apoptotic Bcl-2-family protein Bim belongs to the BH3-only proteins known as initiators of apoptosis. Recent data show that Bim is constitutively inserted in the outer mitochondrial membrane via a C-terminal transmembrane anchor from where it can activate the effector of cytochrome c-release, Bax. To identify regulators of Bim-activity, we conducted a search for proteins interacting with Bim at mitochondria. We found an interaction of Bim with Tom70, Tom20 and more weakly with Tom40, all components of the Translocase of the Outer Membrane (TOM). In vitro import assays performed on tryptically digested yeast mitochondria showed reduced Bim insertion into the outer mitochondrial membrane (OMM) indicating that protein receptors may be involved in the import process. However, RNAi against components of TOM (Tom40, Tom70, Tom22 or Tom20) by siRNA, individually or in combination, did not consistently change the amount of Bim on HeLa mitochondria, either at steady state or upon de novo-induction. In support of this, the individual or combined knockdowns of TOM receptors also failed to alter the susceptibility of HeLa cells to Bim-induced apoptosis. In isolated yeast mitochondria, lack of Tom70 or the TOM-components Tom20 or Tom22 alone did not affect the import of Bim into the outer mitochondrial membrane. In yeast, expression of Bim can sensitize the cells to Bax-dependent killing. This sensitization was unaffected by the absence of Tom70 or by an experimental reduction in Tom40. Although thus the physiological role of the Bim-TOM-interaction remains unclear, TOM complex components do not seem to be essential for Bim insertion into the OMM. Nevertheless, this association should be noted and considered when the regulation of Bim in other cells and situations is investigated.
KW  - bax
KW  - preproteins
KW  - phosphorylation
KW  - proteomics
KW  - degradation
KW  - cells
KW  - family
KW  - import
KW  - BH3 domains
KW  - Bcl-2 proteins
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143301
VL  - 10
IS  - 4
ER  - 
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  -