Dataset Information

A proteomics study identifying interactors of the FSHD2 gene product SMCHD1 reveals RUVBL1-dependent DUX4 repression.

ABSTRACT: Structural Maintenance of Chromosomes Hinge Domain Containing 1 (SMCHD1) is a chromatin repressor, which is mutated in >95% of Facioscapulohumeral dystrophy (FSHD) type 2 cases. In FSHD2, SMCHD1 mutations ultimately result in the presence of the cleavage stage transcription factor DUX4 in muscle cells due to a failure in epigenetic repression of the D4Z4 macrosatellite repeat on chromosome 4q, which contains the DUX4 locus. While binding of SMCHD1 to D4Z4 and its necessity to maintain a repressive D4Z4 chromatin structure are well documented, it is unclear how SMCHD1 is recruited to D4Z4, and how it exerts its repressive properties on the chromatin. Here, we employ a quantitative proteomics approach to identify and characterize novel SMCHD1 interacting proteins, and assess their functionality in D4Z4 repression. We identify 47 robust SMCHD1 interactors, of which 19 are present in D4Z4 chromatin. We demonstrate that one of these SMCHD1 interacting proteins in D4Z4, RuvB-like 1 (RUVBL1) is indeed required for maintaining DUX4 silencing in FSHD myocytes. We also confirm the interaction of SMCHD1 with EZH inhibitory protein (EZHIP), which prevents global H3K27me3 deposition by the Polycomb repressive complex PRC2, providing novel insights into the potential function of SMCHD1 in the repression of DUX4 in the early stages of embryogenesis. The SMCHD1 interactome outlined herein can thus provide further direction into research on the potential function of SMCHD1 at genomic loci where SMCHD1 is known to act, such as D4Z4 repeats, the inactive X chromosome, autosomal gene clusters, imprinted loci and telomeres.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Román González-Prieto

LAB HEAD: Alfred C.O. Vertegaal

PROVIDER: PXD023993 | Pride | 2021-12-15

REPOSITORIES: Pride

ACCESS DATA

Publications

A proteomics study identifying interactors of the FSHD2 gene product SMCHD1 reveals RUVBL1-dependent DUX4 repression.

Goossens Remko R Tihaya Mara S MS van den Heuvel Anita A Tabot-Ndip Klorane K Willemsen Iris M IM Tapscott Stephen J SJ González-Prieto Román R Chang Jer-Gung JG Vertegaal Alfred C O ACO Balog Judit J van der Maarel Silvère M SM

Scientific reports 20211208 1

Structural Maintenance of Chromosomes Hinge Domain Containing 1 (SMCHD1) is a chromatin repressor, which is mutated in > 95% of Facioscapulohumeral dystrophy (FSHD) type 2 cases. In FSHD2, SMCHD1 mutations ultimately result in the presence of the cleavage stage transcription factor DUX4 in muscle cells due to a failure in epigenetic repression of the D4Z4 macrosatellite repeat on chromosome 4q, which contains the DUX4 locus. While binding of SMCHD1 to D4Z4 and its necessity to maintain a repress ...[more]

PMID: 34880314

Similar Datasets

Project description:DUX4 is a double homeodomain transcription factor whose misexpression in the muscle causes facioscapulohumeral muscular dystrophy (FSHD). The transcriptional activity of DUX4 has been extensively characterized, and is thought to be the primary driver of FSHD pathogenesis. Yet, DUX4 expression lowers the protein level of an RNA quality control factor, UPF1, without affecting its transcript level, hinting at post-transcriptional regulatory activity downstream of DUX4 expression. How extensive the post-transcriptional activity of DUX4 is, and how relevant it is to FSHD pathogenesis, is unknown. In order to gain insight into DUX4-induced post-transcriptional gene regulation, we measured transcript and protein levels in DUX4 expressing cells via RNA-seq and SILAC-based quantitative mass spectrometry, respectively. We show that DUX4 transcriptional targets are robustly translated, including those genes previously identified as potential FSHD biomarkers. However, comparing the overall pattern of gene expression changes for RNA versus protein reveals striking differences in the most highly activated pathways, with the former showing changes in RNA processing and splicing, and the latter affecting the humoral immune response, proteolysis and exocytosis, among other pathways. Consistent with a misregulation of exocytosis, fluorescence imaging shows fragmented golgi apparatus in DUX4-expressing cells. Of the genes that showed discordant RNA and protein expression levels, post-transcriptional buffering was particularly evident for genes involved in stress response and may explain why DUX4-expressing cells succumb to toxicity despite robust transcriptional activation of stress response genes. Moreover, several genes involved in RNA decay including UPF1, UPF3B, SMG6 and XRN1 showed downregulation at the protein level, which may explain the massive inhibition of RNA quality control in DUX4-expressing cells. These results highlight the importance of considering post-transcriptional gene regulation in DUX4-expressing cells in order to fully understand the FSHD disease process.

Dataset Information

A proteomics study identifying interactors of the FSHD2 gene product SMCHD1 reveals RUVBL1-dependent DUX4 repression.

Publications

A proteomics study identifying interactors of the FSHD2 gene product SMCHD1 reveals RUVBL1-dependent DUX4 repression.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure