Degradation of the Neurospora circadian clock protein FREQUENCY through the ubiquitin–proteasome pathway

2005 ◽  
Vol 33 (5) ◽  
pp. 953 ◽  
Author(s):  
Y. Liu ◽  
Q. He
Keyword(s):  
Circadian Clock ◽  
Ubiquitin Proteasome Pathway ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
Clock Protein

Degradation of the Neurospora circadian clock protein FREQUENCY through the ubiquitin–proteasome pathway

2005 ◽  
Vol 33 (5) ◽  
pp. 953-956 ◽  
Author(s):  
Q. He ◽  
Y. Liu
Keyword(s):  
Circadian Clock ◽  
Major Function ◽  
Ubiquitin Proteasome Pathway ◽  
Mutant Strains ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
The Stability ◽  
Clock Protein

Phosphorylation of the Neurospora circadian clock protein FREQUENCY (FRQ) promotes its degradation through the ubiquitin–proteasome pathway. Ubiquitination of FRQ requires FWD-1 (F-box/WD-40 repeat-containing protein-1), which is the substrate-recruiting subunit of an SCF (SKP/Cullin/F-box)-type ubiquitin ligase. In the fwd-1 mutant strains, FRQ degradation is defective, resulting in the accumulation of hyperphosphorylated FRQ and the loss of the circadian rhythmicities. The CSN (COP9 signalosome) promotes the function of SCF complexes in vivo. But in vitro, deneddylation of cullins by CSN inhibits SCF activity. In Neurospora, the disruption of the csn-2 subunit impairs FRQ degradation and compromises the normal circadian functions. These defects are due to the dramatically reduced levels of FWD-1 in the csn-2 mutant, a result of its rapid degradation. Other components of the SCFFWD−1 complex, SKP-1 and CUL-1 are also unstable in the mutant. These results establish important roles for SCFFWD−1 and CSN in the circadian clock of Neurospora and suggest that they are conserved components of the eukaryotic circadian clocks. In addition, these findings resolve the CSN paradox and suggest that the major function of CSN is to maintain the stability of SCF ubiquitin ligases in vivo.

The Ubiquitin-Proteasome Pathway an Emerging Anticancer Strategy for Therapeutics: A Patent Analysis

2015 ◽  
Vol 10 (2) ◽  
pp. 201-213 ◽  
Author(s):  
Chakresh Jain ◽  
Shivam Arora ◽  
Aparna Khanna ◽  
Money Gupta ◽  
Gulshan Wadhwa ◽  
...  
Keyword(s):  
Patent Analysis ◽  
Ubiquitin Proteasome Pathway ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway

scholarly journals Toll-like Receptor 4 Signaling in Ventilator-induced Diaphragm Atrophy

2012 ◽  
Vol 117 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Willem-Jan M. Schellekens ◽  
Hieronymus W. H. van Hees ◽  
Michiel Vaneker ◽  
Marianne Linkels ◽  
P. N. Richard Dekhuijzen ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Caspase 3 ◽  
Toll Like Receptor ◽  
Wild Type ◽  
Toll Like Receptor 4 ◽  
Ubiquitin Proteasome Pathway ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
Diaphragm Atrophy ◽  
Deficient Mice

Background Mechanical ventilation induces diaphragm muscle atrophy, which plays a key role in difficult weaning from mechanical ventilation. The signaling pathways involved in ventilator-induced diaphragm atrophy are poorly understood. The current study investigated the role of Toll-like receptor 4 signaling in the development of ventilator-induced diaphragm atrophy. Methods Unventilated animals were selected for control: wild-type (n = 6) and Toll-like receptor 4 deficient mice (n = 6). Mechanical ventilation (8 h): wild-type (n = 8) and Toll-like receptor 4 deficient (n = 7) mice.Myosin heavy chain content, proinflammatory cytokines, proteolytic activity of the ubiquitin-proteasome pathway, caspase-3 activity, and autophagy were measured in the diaphragm. Results Mechanical ventilation reduced myosin content by approximately 50% in diaphragms of wild-type mice (P less than 0.05). In contrast, ventilation of Toll-like receptor 4 deficient mice did not significantly affect diaphragm myosin content. Likewise, mechanical ventilation significantly increased interleukin-6 and keratinocyte-derived chemokine in the diaphragm of wild-type mice, but not in ventilated Toll-like receptor 4 deficient mice. Mechanical ventilation increased diaphragmatic muscle atrophy factor box transcription in both wild-type and Toll-like receptor 4 deficient mice. Other components of the ubiquitin-proteasome pathway and caspase-3 activity were not affected by ventilation of either wild-type mice or Toll-like receptor 4 deficient mice. Mechanical ventilation induced autophagy in diaphragms of ventilated wild-type mice, but not Toll-like receptor 4 deficient mice. Conclusion Toll-like receptor 4 signaling plays an important role in the development of ventilator-induced diaphragm atrophy, most likely through increased expression of cytokines and activation of lysosomal autophagy.

Mergla K + channel induces skeletal muscle atrophy by activating the ubiquitin proteasome pathway

2006 ◽  
Vol 20 (9) ◽  
pp. 1531-1533 ◽  
Author(s):  
Xun Wang ◽  
Gregory H. Hockerman ◽  
Henry W. Green ◽  
Charles F. Babbs ◽  
Sulma I. Mohammad ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Skeletal Muscle Atrophy ◽  
K Channel ◽  
Ubiquitin Proteasome Pathway ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway
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