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Spatial and Temporal Analysis of Active ERK in the C. elegans Germline
Published on: November 29, 2016
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praja2 regulates KSR1 stability and mitogenic signaling
L Rinaldi1, R Delle Donne1, M Sepe1
1Dipartimento di Medicina Molecolare e Biotecnologie Mediche, IEOS-CNR, CEINGE University Federico II, Naples 80131, Italy.
Cell Death & Disease
|May 20, 2016
Summary
The kinase suppressor of Ras 1 (KSR1) is degraded via ubiquitination, a process regulated by praja2. This mechanism controls ERK signaling, impacting cell proliferation and stem cell pluripotency.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Kinase suppressor of Ras 1 (KSR1) is crucial for Ras/MAP kinase pathway signaling.
- KSR1 scaffolds signaling components to activate ERK, a key mitogenic pathway.
- Regulation of KSR1 stability is essential for controlling cellular responses.
Purpose of the Study:
- To elucidate a novel mechanism for ERK pathway attenuation.
- To identify the E3 ligase responsible for KSR1 degradation.
- To investigate the role of KSR1 ubiquitination in cancer cell growth and stem cell pluripotency.
Main Methods:
- Studied KSR1 polyubiquitination upon growth factor stimulation.
- Identified praja2 as the E3 ligase targeting KSR1.
- Assessed the impact of praja2-dependent KSR1 regulation on ERK signaling, cancer cell proliferation, and embryonic stem cell pluripotency.
Main Results:
- Hormone or growth factor stimulation induced KSR1 polyubiquitination, correlating with decreased ERK1/2 signaling.
- Praja2 was identified as the E3 ligase responsible for KSR1 ubiquitination.
- Praja2-mediated regulation of KSR1 influences cancer cell growth and maintains the pluripotent state of mouse embryonic stem cells.
Conclusions:
- Ubiquitin-dependent proteolysis of KSR1 represents a novel mechanism for ERK pathway attenuation.
- Praja2 plays a critical role in regulating KSR1 levels and downstream signaling.
- The interplay between ubiquitination and KSR1 scaffolding impacts cell proliferation and stem cell pluripotency, offering potential therapeutic targets.
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