ClipR-59 interacts with Elmo2 and modulates myoblast fusion
Yingmin Sun1, Wenying Ren2, Jean-François Côté3
1From the State Key Laboratory for Agro-biotechnology, College of Biological Science, China Agricultural University, 10083 Beijing, China, the Molecular Oncology Research Institute, Tufts Medical Center, Boston, Massachusetts 02111, and.
Abstract:
Recent studies using ClipR-59 knock-out mice implicated this protein in the regulation of muscle function. In this report, we have examined the role of ClipR-59 in muscle differentiation and found that ClipR-59 knockdown in C2C12 cells suppressed myoblast fusion. To elucidate the molecular mechanism whereby ClipR-59 regulates myoblast fusion, we carried out a yeast two-hybrid screen using ClipR-59 as the bait and identified Elmo2, a member of the Engulfment and cell motility protein family, as a novel ClipR-59-associated protein. We showed that the interaction between ClipR-59 and Elmo2 was mediated by the atypical PH domain of Elmo2 and the Glu-Pro-rich domain of ClipR-59 and regulated by Rho-GTPase. We have examined the impact of ClipR-59 on Elmo2 downstream signaling and found that interaction of ClipR-59 with Elmo2 enhanced Rac1 activation. Collectively, our studies demonstrate that formation of an Elmo2·ClipR-59 complex plays an important role in myoblast fusion.
Insights
ClipR-59 protein is crucial for muscle cell fusion. It interacts with Elmo2 (Engulfment and cell motility protein 2) to regulate Rac1 activation, essential for proper muscle development.
Area of Science:
- Molecular Biology
- Cell Biology
- Muscle Physiology
Background:
- ClipR-59 (Clip domain-containing protein 5) has been implicated in muscle function.
- Understanding the molecular mechanisms regulating muscle differentiation is critical for addressing muscle-related disorders.
Purpose of the Study:
- To investigate the role of ClipR-59 in muscle differentiation and myoblast fusion.
- To identify molecular partners of ClipR-59 involved in myoblast fusion.
- To elucidate the signaling pathways regulated by the ClipR-59-Elmo2 complex.
Main Methods:
- ClipR-59 knockdown in C2C12 myoblasts.
- Yeast two-hybrid screening to identify interacting proteins.
- Co-immunoprecipitation to confirm protein interactions.
- Analysis of Rho-GTPase activity and downstream signaling (Rac1 activation).
Main Results:
- ClipR-59 knockdown suppressed myoblast fusion in C2C12 cells.
- Elmo2 was identified as a novel binding partner of ClipR-59.
- The interaction between ClipR-59 and Elmo2 is mediated by specific protein domains and regulated by Rho-GTPase.
- The ClipR-59-Elmo2 complex enhances Rac1 activation, a key regulator of cell motility and fusion.
Conclusions:
- ClipR-59 plays a significant role in regulating myoblast fusion.
- The formation of an Elmo2·ClipR-59 complex is essential for myoblast fusion.
- This complex modulates Rac1 signaling, highlighting a novel pathway in muscle development.
