Absolute quantification of cohesin, CTCF and their regulators in human cells
Abstract
The organisation of mammalian genomes into loops and topologically associating domains (TADs) contributes to chromatin structure, gene expression and recombination. TADs and many loops are formed by cohesin and positioned by CTCF. In proliferating cells, cohesin also mediates sister chromatid cohesion, which is essential for chromosome segregation. Current models of chromatin folding and cohesion are based on assumptions of how many cohesin and CTCF molecules organise the genome. Here we have measured absolute copy numbers and dynamics of cohesin, CTCF, NIPBL, WAPL and sororin by mass spectrometry, fluorescence-correlation spectroscopy and fluorescence recovery after photobleaching in HeLa cells. In G1-phase there are ~250,000 nuclear cohesin complexes, of which ~160,000 are chromatin-bound. Comparison with chromatin immunoprecipitation-sequencing data implies that some genomic cohesin and CTCF enrichment sites are unoccupied in single cells at any one time. We discuss the implications of these findings for how cohesin can contribute to genome organisation and cohesion.
Data availability
Mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD012712. Sequencing data have been deposited in GEO (GSE126990.
-
ChIP-seq data from Absolute quantification of cohesin, CTCF and their regulators in human cellsNCBI Gene Expression Omnibus, GSE126990.
Article and author information
Author details
Funding
Boehringer Ingelheim
- Johann Holzmann
- Kota Nagasaka
- Johannes Fuchs
- Gerhard Dürnberger
- Wen Tang
- Rene Ladurner
- Georg A Busslinger
- Karl Mechtler
- Iain Finley Davidson
- Jan-Michael Peters
European Molecular Biology Laboratory
- Antonio Z Politi
- Merle Hantsche-Grininger
- Nike Walther
- Birgit Koch
- Jan Ellenberg
National Institutes of Health (Common Fund 4D Nucleome Program (U01 EB021223 / U01 DA047728))
- Jan Ellenberg
Paul G. Allen Frontiers Group (Allen Distinguished Investigator Program)
- Jan Ellenberg
EMBL International PhD Programme
- Nike Walther
Austrian Research Promotion Agency (FFG-852936)
- Jan-Michael Peters
Austrian Research Promotion Agency (Laura Bassi Centre for Optimized Structural Studies grant FFG-840283)
- Jan-Michael Peters
Austrian Science Fund (Wittgenstein award Z196-B20)
- Jan-Michael Peters
Horizon 2020 Framework Programme (653706)
- Jan Ellenberg
Horizon 2020 Framework Programme (823839)
- Karl Mechtler
Austrian Science Fund (I 3686-B25 MEIOREC - ERA-CAPS)
- Karl Mechtler
Austrian Science Fund (FWF special research program SFB F34)
- Jan-Michael Peters
Austrian Research Promotion Agency (FFG-834223)
- Jan-Michael Peters
Vienna Science and Technology Fund (WWTF LS09-13)
- Jan-Michael Peters
Seventh Framework Programme (241548 (MitoSys))
- Jan Ellenberg
- Jan-Michael Peters
Horizon 2020 Framework Programme (693949)
- Jan-Michael Peters
Sixth Framework Programme (503464 (MitoCheck))
- Jan-Michael Peters
European Molecular Biology Organization (ALTF 1335-2016)
- Kota Nagasaka
Human Frontier Science Program (LT001527/2017)
- Kota Nagasaka
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- David J Sherratt, University of Oxford, United Kingdom
Version history
- Received: February 20, 2019
- Accepted: June 13, 2019
- Accepted Manuscript published: June 17, 2019 (version 1)
- Version of Record published: July 2, 2019 (version 2)
- Version of Record updated: July 22, 2019 (version 3)
Copyright
© 2019, Holzmann 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
-
- 4,875
- views
-
- 922
- downloads
-
- 78
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
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)
Further reading
-
- Cell Biology
- Neuroscience
Mutations in Drosophila Swiss cheese (SWS) gene or its vertebrate orthologue neuropathy target esterase (NTE) lead to progressive neuronal degeneration in flies and humans. Despite its enzymatic function as a phospholipase is well established, the molecular mechanism responsible for maintaining nervous system integrity remains unclear. In this study, we found that NTE/SWS is present in surface glia that forms the blood-brain barrier (BBB) and that NTE/SWS is important to maintain its structure and permeability. Importantly, BBB glia-specific expression of Drosophila NTE/SWS or human NTE in the sws mutant background fully rescues surface glial organization and partially restores BBB integrity, suggesting a conserved function of NTE/SWS. Interestingly, sws mutant glia showed abnormal organization of plasma membrane domains and tight junction rafts accompanied by the accumulation of lipid droplets, lysosomes, and multilamellar bodies. Since the observed cellular phenotypes closely resemble the characteristics described in a group of metabolic disorders known as lysosomal storage diseases (LSDs), our data established a novel connection between NTE/SWS and these conditions. We found that mutants with defective BBB exhibit elevated levels of fatty acids, which are precursors of eicosanoids and are involved in the inflammatory response. Also, as a consequence of a permeable BBB, several innate immunity factors are upregulated in an age-dependent manner, while BBB glia-specific expression of NTE/SWS normalizes inflammatory response. Treatment with anti-inflammatory agents prevents the abnormal architecture of the BBB, suggesting that inflammation contributes to the maintenance of a healthy brain barrier. Considering the link between a malfunctioning BBB and various neurodegenerative diseases, gaining a deeper understanding of the molecular mechanisms causing inflammation due to a defective BBB could help to promote the use of anti-inflammatory therapies for age-related neurodegeneration.
-
- Cancer Biology
- Cell Biology
Enhanced protein synthesis is a crucial molecular mechanism that allows cancer cells to survive, proliferate, metastasize, and develop resistance to anti-cancer treatments, and often arises as a consequence of increased signaling flux channeled to mRNA-bearing eukaryotic initiation factor 4F (eIF4F). However, the post-translational regulation of eIF4A1, an ATP-dependent RNA helicase and subunit of the eIF4F complex, is still poorly understood. Here, we demonstrate that IBTK, a substrate-binding adaptor of the Cullin 3-RING ubiquitin ligase (CRL3) complex, interacts with eIF4A1. The non-degradative ubiquitination of eIF4A1 catalyzed by the CRL3IBTK complex promotes cap-dependent translational initiation, nascent protein synthesis, oncogene expression, and cervical tumor cell growth both in vivo and in vitro. Moreover, we show that mTORC1 and S6K1, two key regulators of protein synthesis, directly phosphorylate IBTK to augment eIF4A1 ubiquitination and sustained oncogenic translation. This link between the CRL3IBTK complex and the mTORC1/S6K1 signaling pathway, which is frequently dysregulated in cancer, represents a promising target for anti-cancer therapies.