Homologous Transcription Factors DUX4 and DUX4c Associate with Cytoplasmic Proteins during Muscle Differentiation
Authors
Ansseau, EugenieEidahl, Jocelyn O.
Lancelot, Celine
Tassin, Alexandra
Matteotti, Christel
Yip, Cassandre
Liu, Jian
Leroy, Baptiste
Hubeau, Celine
Gerbaux, Cecile
Cloet, Samuel
Wauters, Armelle
Zorbo, Sabrina
Meyer, Pierre
Pirson, Isabelle
Laoudj-Chenivesse, Dalila
Wattiez, Ruddy
Harper, Scott Q.
Belayew, Alexandra
Coppee, Frederique
UMass Chan Affiliations
Wellstone Center for FSHDDocument Type
Journal ArticlePublication Date
2016-01-27Keywords
Cell BiologyDevelopmental Biology
Molecular Biology
Molecular Genetics
Musculoskeletal Diseases
Nervous System Diseases
Metadata
Show full item recordAbstract
Hundreds of double homeobox (DUX) genes map within 3.3-kb repeated elements dispersed in the human genome and encode DNA-binding proteins. Among these, we identified DUX4, a potent transcription factor that causes facioscapulohumeral muscular dystrophy (FSHD). In the present study, we performed yeast two-hybrid screens and protein co-purifications with HaloTag-DUX fusions or GST-DUX4 pull-down to identify protein partners of DUX4, DUX4c (which is identical to DUX4 except for the end of the carboxyl terminal domain) and DUX1 (which is limited to the double homeodomain). Unexpectedly, we identified and validated (by co-immunoprecipitation, GST pull-down, co-immunofluorescence and in situ Proximal Ligation Assay) the interaction of DUX4, DUX4c and DUX1 with type III intermediate filament protein desmin in the cytoplasm and at the nuclear periphery. Desmin filaments link adjacent sarcomere at the Z-discs, connect them to sarcolemma proteins and interact with mitochondria. These intermediate filament also contact the nuclear lamina and contribute to positioning of the nuclei. Another Z-disc protein, LMCD1 that contains a LIM domain was also validated as a DUX4 partner. The functionality of DUX4 or DUX4c interactions with cytoplasmic proteins is underscored by the cytoplasmic detection of DUX4/DUX4c upon myoblast fusion. In addition, we identified and validated (by co-immunoprecipitation, co-immunofluorescence and in situ Proximal Ligation Assay) as DUX4/4c partners several RNA-binding proteins such as C1QBP, SRSF9, RBM3, FUS/TLS and SFPQ that are involved in mRNA splicing and translation. FUS and SFPQ are nuclear proteins, however their cytoplasmic translocation was reported in neuronal cells where they associated with ribonucleoparticles (RNPs). Several other validated or identified DUX4/DUX4c partners are also contained in mRNP granules, and the co-localizations with cytoplasmic DAPI-positive spots is in keeping with such an association. Large muscle RNPs were recently shown to exit the nucleus via a novel mechanism of nuclear envelope budding. Following DUX4 or DUX4c overexpression in muscle cell cultures, we observed their association with similar nuclear buds. In conclusion, our study demonstrated unexpected interactions of DUX4/4c with cytoplasmic proteins playing major roles during muscle differentiation. Further investigations are on-going to evaluate whether these interactions play roles during muscle regeneration as previously suggested for DUX4c.Source
PLoS One. 2016 Jan 27;11(1):e0146893. doi: 10.1371/journal.pone.0146893. eCollection 2016. Link to article on publisher's siteDOI
10.1371/journal.pone.0146893Permanent Link to this Item
http://hdl.handle.net/20.500.14038/50571PubMed ID
26816005Related Resources
Link to Article in PubMedRights
Copyright: © 2016 Ansseau et al.Distribution License
http://creativecommons.org/licenses/by/4.0/ae974a485f413a2113503eed53cd6c53
10.1371/journal.pone.0146893