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Identification of MyoD Interactome Using Tandem Affinity Purification Coupled to Mass Spectrometry
Published on: May 17, 2016
Cdkn1c drives muscle differentiation through a positive feedback loop with Myod.
Daniel P S Osborn1, Kuoyu Li, Yaniv Hinits
1King's College London, Randall Division for Cell and Molecular Biophysics, London, UK.
Developmental Biology
|December 15, 2010
Summary
Hedgehog signaling enhances muscle development by increasing Myod protein activity through cdkn1c induction. This positive feedback loop drives myogenic cells toward terminal differentiation.
Area of Science:
- Developmental Biology
- Cellular Signaling
- Molecular Genetics
Background:
- Muscle differentiation (myogenesis) involves converting analog signals to binary outputs via positive feedback.
- Hedgehog (Hh) signaling is crucial for vertebrate myogenesis, primarily by elevating muscle regulatory factors (MRFs) like Myod above a critical threshold.
- While Hh signaling enhances MRF expression, its role in modulating Myod protein activity remains less understood.
Purpose of the Study:
- To elucidate the role of Hedgehog signaling in the post-transcriptional regulation of Myod activity during muscle differentiation.
- To investigate the molecular mechanisms by which Hh signaling influences Myod protein function beyond gene expression.
- To identify downstream targets of Hh signaling that mediate enhanced Myod activity and promote terminal differentiation.
Main Methods:
- Utilized zebrafish as a model organism for studying early muscle fiber development.
- Employed genetic manipulation to assess the requirement of Hh signaling and Cdkn1c in myogenesis.
- Analyzed gene and protein expression levels of key myogenic factors, including Myod and Cdkn1c (p57Kip2).
- Investigated the interplay between Myod and Cdkn1c in driving cell cycle exit and differentiation.
Main Results:
- Hedgehog signaling is essential for a secondary step that enhances Myod protein activity, independent of its role in MRF expression.
- Hh signaling induces the expression of cdkn1c (p57Kip2) in slow muscle precursor cells.
- Neither Hh nor Cdkn1c is required for the cell cycle exit of these precursor cells.
- Cdkn1c collaborates with Myod to promote the differentiation of various early zebrafish muscle fiber types.
- Myod positively regulates cdkn1c expression, establishing a feedback loop.
Conclusions:
- Hedgehog signaling plays a dual role in myogenesis: enhancing MRF expression and increasing Myod protein activity.
- Cdkn1c acts as a key mediator of Hh's effect on Myod activity, facilitating terminal differentiation.
- A positive feedback loop between Myod and cdkn1c is established, driving myogenic cells towards differentiation.
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