Actin-related protein 5 functions as a novel modulator of MyoD and MyoG in skeletal muscle and in rhabdomyosarcoma

Abstract
Data availability
Article and author information

Abstract

Myogenic regulatory factors (MRFs) are pivotal transcription factors in myogenic differentiation. MyoD commits cells to the skeletal muscle lineage by inducing myogenic genes through recruitment of chromatin remodelers to its target loci. This study showed that Actin-related protein 5 (Arp5) acts as an inhibitory regulator of MyoD and MyoG by binding to their cysteine-rich (CR) region, which overlaps with the region essential for their epigenetic functions. Arp5 expression was faint in skeletal muscle tissues. Excessive Arp5 in mouse hind limbs caused skeletal muscle fiber atrophy. Further, Arp5 overexpression in myoblasts inhibited myotube formation by diminishing myogenic gene expression, whereas Arp5 depletion augmented myogenic gene expression. Arp5 disturbed MyoD-mediated chromatin remodeling through competition with the three-amino-acid-loop-extension-class homeodomain transcription factors the Pbx1–Meis1 heterodimer for binding to the CR region. This antimyogenic function was independent of the INO80 chromatin remodeling complex, although Arp5 is an important component of that. In rhabdomyosarcoma (RMS) cells, Arp5 expression was significantly higher than in normal myoblasts and skeletal muscle tissue, probably contributing to MyoD and MyoG activity dysregulation. Arp5 depletion in RMS partially restored myogenic properties while inhibiting tumorigenic properties. Thus, Arp5 is a novel modulator of MRFs in skeletal muscle differentiation.

Data availability

DNA microarray data have been deposited in the GEO database https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE169681 (accession no. GSE169681).ChIP-Seq data have been deposited in the DDBJ database https://ddbj.nig.ac.jp/resource/bioproject/PRJDB13012 (Run accession no. DRR345782-DRR345785).All data generated or analysed during this study are included in the manuscript and supporting files; Source Data files have been provided for Figures 1, 2, 3, 4, 5, 6 and 7.

The following data sets were generated

1. Morita T
2. Hayashi K
(2021) Knockdown of Ino80 complex subunits Actr5, Ies6, and Ino80 in RD cells
NCBI Gene Expression Omnibus, GSE169681.

https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE169681
1. Tsuyoshi Morita
(2022) Comparison of MyoD binding sites in WT and Arp5-KO RD cells [ChIP-seq]
DNA Data Bank of Japan, PRJDB13012.

https://ddbj.nig.ac.jp/resource/bioproject/PRJDB13012

The following previously published data sets were used

1. Sarver A
(2011) Endothelial and Alveolar Rhabdomyosarcoma mRNA expression
NCBI Gene Expression Omnibus; GSE28511.

https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE28511

Article and author information

Author details

Tsuyoshi Morita

Department of Biology, Wakayama Medical University, Wakayama, Japan

For correspondence
tsuyo@wakayama-med.ac.jp

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0002-9022-298X
Ken'ichiro Hayashi

Department of RNA Biology and Neuroscience, Osaka University, Osaka, Japan

Competing interests
The authors declare that no competing interests exist.

Funding

Japan Society for the Promotion of Science (KAKENHI 15K07076)

Tsuyoshi Morita

Japan Society for the Promotion of Science (KAKENHI 18K06913)

Tsuyoshi Morita

Japan Society for the Promotion of Science (KAKENHI 19K07351)

Ken'ichiro Hayashi

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: All animal experiments were conducted in accordance with the guidelines for animal experiments specified by the Wakayama Medical University, Japan, and Osaka University School of Medicine, Japan. The Protocols were approved by the Committee on the Ethics of Animal Experiments of the Wakayama Medical University (Permit Number: 900 ) and Osaka University School of Medicine (Permit Number: 28-018).

Copyright

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.