Next Article in Journal
A Cleared View on Retinal Organoids
Previous Article in Journal
Cholesterol Trafficking: An Emerging Therapeutic Target for Angiogenesis and Cancer
Article Menu

Export Article

Open AccessArticle

Telomere Function and the G-Quadruplex Formation are Regulated by hnRNP U

1 and 2,3,*
1
Department of Occupational Pneumology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Fukuoka 807-8555, Japan
2
Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, SE-40530 Gothenburg, Sweden
3
Oncology Laboratory, University of Gothenburg, Sahlgrenska Hospital, Gula stråket 8, SE-41345 Gothenburg, Sweden
*
Author to whom correspondence should be addressed.
Cells 2019, 8(5), 390; https://doi.org/10.3390/cells8050390
Received: 13 March 2019 / Revised: 22 April 2019 / Accepted: 25 April 2019 / Published: 28 April 2019
(This article belongs to the Section Cell Signaling and Regulated Cell Death)
  |  
PDF [2079 KB, uploaded 28 April 2019]
  |     |  

Abstract

We examine the role of the heterogenous ribonucleoprotein U (hnRNP U) as a G-quadruplex binding protein in human cell lines. Hypothesizing that hnRNP U is associated with telomeres, we investigate what other telomere-related functions it may have. Telomeric G-quadruplexes have been fully characterized in vitro, but until now no clear evidence of their function or in vivo interactions with proteins has been revealed in mammalian cells. Techniques used were immunoprecipitation, DNA pull-down, binding assay, and Western blots. We identified hnRNP U as a G-quadruplex binding protein. Immunoprecipitations disclosed that endogenous hnRNP U associates with telomeres, and DNA pull-downs showed that the hnRNP U C-terminus specifically binds telomeric G-quadruplexes. We have compared the effect of telomere repeat containing RNA (TERRA) on binding between hnRNP U and telomeric (Tel) or single- stranded Tel (ssTel) oligonucleotides and found that ssTel binds stronger to TERRA than to Tel. We also show that hnRNP U prevents replication protein A (RPA) accumulation at telomeres, and the recognition of telomeric ends by hnRNP suggests that a G-quadruplex promoting protein regulates its accessibility. Thus, hnRNP U-mediated formation has important functions for telomere biology. View Full-Text
Keywords: telomeres; hnRNP U; G-quadruplex; ssTel-oligonucleotide; Tel-oligonucleotide; RPA telomeres; hnRNP U; G-quadruplex; ssTel-oligonucleotide; Tel-oligonucleotide; RPA
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Izumi, H.; Funa, K. Telomere Function and the G-Quadruplex Formation are Regulated by hnRNP U. Cells 2019, 8, 390.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Cells EISSN 2073-4409 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top