Myogenin controls via AKAP6 non-centrosomal microtubule organizing center formation at the nuclear envelope
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
- Sorbonne Universités, France
Abstract
Non-centrosomal microtubule organizing centers (MTOC) are pivotal for the function of multiple cell types, but the processes initiating their formation are unknown. Here, we find that the transcription factor myogenin is required in murine myoblasts for the localization of MTOC proteins to the nuclear envelope. Moreover, myogenin is sufficient in fibroblasts for nuclear envelope MTOC (NE-MTOC) formation and centrosome attenuation. Bioinformatics combined with loss- and gain-of-function experiments identified induction of AKAP6 expression as one central mechanism for myogenin-mediated NE-MTOC formation. Promoter studies indicate that myogenin preferentially induces the transcription of muscle- and NE-MTOC-specific isoforms of Akap6 and Syne1, which encodes nesprin-1α, the NE-MTOC anchor protein in muscle cells. Overexpression of AKAP6β and nesprin-1α was sufficient to recruit endogenous MTOC proteins to the nuclear envelope of myoblasts in the absence of myogenin. Taken together, our results illuminate how mammals transcriptionally control the switch from a centrosomal MTOC to an NE-MTOC and identify AKAP6 as a novel NE-MTOC component in muscle cells.
Data availability
This work is based exclusively on the analysis of previously published data sets.
-
Transcription Factor Binding Sites by ChIP-seq from ENCODE/CaltechGene Expression Omnibus (GEO) GSE36024.
-
Transcriptome changes during the differentiation of myoblasts into myotubesGene Expression Omnibus (GEO) GSE84158.
Article and author information
Author details
Silvia Vergarajauregui
Funding
Interdisciplinary Center for Clinical Research , Uniklinikum Erlangen (J42)
- Fulvia Ferrazzi
Friedrich-Alexander-Universität Erlangen-Nürnberg (ELAN-16-01-04-1-Vergarajauregui)
- Silvia Vergarajauregui
Friedrich-Alexander-Universität Erlangen-Nürnberg (CYDER)
- Felix B Engel
Deutsche Forschungsgemeinschaft (INST 410/91-1 FUGG)
- Felix B Engel
Deutsche Forschungsgemeinschaft (EN 453/12-1)
- Felix B Engel
Research Foundation Medicine at the University Clinic Erlangen
- Silvia Vergarajauregui
- Felix B Engel
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Jens Lüders, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Spain
Version history
- Preprint posted: December 11, 2020 (view preprint)
- Received: December 11, 2020
- Accepted: October 1, 2021
- Accepted Manuscript published: October 4, 2021 (version 1)
- Version of Record published: October 18, 2021 (version 2)
Copyright
© 2021, Becker et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,345
- views
-
- 228
- downloads
-
- 7
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Myogenin controls via AKAP6 non-centrosomal microtubule organizing center formation at the nuclear envelope
eLife 10:e65672.
https://doi.org/10.7554/eLife.65672
Further reading
-
- Cell Biology
- Structural Biology and Molecular Biophysics
Mutations in the human PURA gene cause the neurodevelopmental PURA syndrome. In contrast to several other monogenetic disorders, almost all reported mutations in this nucleic acid-binding protein result in the full disease penetrance. In this study, we observed that patient mutations across PURA impair its previously reported co-localization with processing bodies. These mutations either destroyed the folding integrity, RNA binding, or dimerization of PURA. We also solved the crystal structures of the N- and C-terminal PUR domains of human PURA and combined them with molecular dynamics simulations and nuclear magnetic resonance measurements. The observed unusually high dynamics and structural promiscuity of PURA indicated that this protein is particularly susceptible to mutations impairing its structural integrity. It offers an explanation why even conservative mutations across PURA result in the full penetrance of symptoms in patients with PURA syndrome.
-
- Cell Biology
Endogenous tags have become invaluable tools to visualize and study native proteins in live cells. However, generating human cell lines carrying endogenous tags is difficult due to the low efficiency of homology-directed repair. Recently, an engineered split mNeonGreen protein was used to generate a large-scale endogenous tag library in HEK293 cells. Using split mNeonGreen for large-scale endogenous tagging in human iPSCs would open the door to studying protein function in healthy cells and across differentiated cell types. We engineered an iPS cell line to express the large fragment of the split mNeonGreen protein (mNG21-10) and showed that it enables fast and efficient endogenous tagging of proteins with the short fragment (mNG211). We also demonstrate that neural network-based image restoration enables live imaging studies of highly dynamic cellular processes such as cytokinesis in iPSCs. This work represents the first step towards a genome-wide endogenous tag library in human stem cells.
