TY  - JOUR
A1  - Weigand, Isabel
A1  - Ronchi, Cristina L.
A1  - Vanselow, Jens T.
A1  - Bathon, Kerstin
A1  - Lenz, Kerstin
A1  - Herterich, Sabine
A1  - Schlosser, Andreas
A1  - Kroiss, Matthias
A1  - Fassnacht, Martin
A1  - Calebiro, Davide
A1  - Sbiera, Silviu
T1  - PKA Cα subunit mutation triggers caspase-dependent RIIβ subunit degradation via Ser\(^{114}\) phosphorylation
JF  - Science Advances
N2  - Mutations in the PRKACA gene are the most frequent cause of cortisol-producing adrenocortical adenomas leading to Cushing’s syndrome. PRKACA encodes for the catalytic subunit α of protein kinase A (PKA). We already showed that PRKACA mutations lead to impairment of regulatory (R) subunit binding. Furthermore, PRKACA mutations are associated with reduced RIIβ protein levels; however, the mechanisms leading to reduced RIIβ levels are presently unknown. Here, we investigate the effects of the most frequent PRKACA mutation, L206R, on regulatory subunit stability. We find that Ser\(^{114}\) phosphorylation of RIIβ is required for its degradation, mediated by caspase 16. Last, we show that the resulting reduction in RIIβ protein levels leads to increased cortisol secretion in adrenocortical cells. These findings reveal the molecular mechanisms and pathophysiological relevance of the R subunit degradation caused by PRKACA mutations, adding another dimension to the deregulation of PKA signaling caused by PRKACA mutations in adrenal Cushing’s syndrome.
KW  - mutation triggers
KW  - phosphorylation
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270445
VL  - 7
IS  - 8
ER  - 
TY  - JOUR
A1  - Harnoš, Jakub
A1  - Cañizal, Maria Consuelo Alonso
A1  - Jurásek, Miroslav
A1  - Kumar, Jitender
A1  - Holler, Cornelia
A1  - Schambony, Alexandra
A1  - Hanáková, Kateřina
A1  - Bernatík, Ondřej
A1  - Zdráhal, Zbynêk
A1  - Gömöryová, Kristína
A1  - Gybeľ, Tomáš
A1  - Radaszkiewicz, Tomasz Witold
A1  - Kravec, Marek
A1  - Trantírek, Lukáš
A1  - Ryneš, Jan
A1  - Dave, Zankruti
A1  - Fernández-Llamazares, Ana Iris
A1  - Vácha, Robert
A1  - Tripsianes, Konstantinos
A1  - Hoffmann, Carsten
A1  - Bryja, Vítězslav
T1  - Dishevelled-3 conformation dynamics analyzed by FRET-based biosensors reveals a key role of casein kinase 1
JF  - Nature Communications
N2  - Dishevelled (DVL) is the key component of the Wnt signaling pathway. Currently, DVL conformational dynamics under native conditions is unknown. To overcome this limitation, we develop the Fluorescein Arsenical Hairpin Binder- (FlAsH-) based FRET in vivo approach to study DVL conformation in living cells. Using this single-cell FRET approach, we demonstrate that (i) Wnt ligands induce open DVL conformation, (ii) DVL variants that are predominantly open, show more even subcellular localization and more efficient membrane recruitment by Frizzled (FZD) and (iii) Casein kinase 1 ɛ (CK1ɛ) has a key regulatory function in DVL conformational dynamics. In silico modeling and in vitro biophysical methods explain how CK1ɛ-specific phosphorylation events control DVL conformations via modulation of the PDZ domain and its interaction with DVL C-terminus. In summary, our study describes an experimental tool for DVL conformational sampling in living cells and elucidates the essential regulatory role of CK1ɛ in DVL conformational dynamics.
KW  - biological techniques
KW  - cell signalling
KW  - phosphorylation
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227837
VL  - 10
ER  -