2D gel electrophoresis reveals dynamics of t-loop formation during the cell cycle and t-loop in maintenance regulated by heterochromatin state

The Journal of Biological Chemistry
Zepeng ZhangYong Zhao

Abstract

Linear chromosome ends are capped by telomeres that have been previously reported to adopt a t-loop structure. The lack of simple methods for detecting t-loops has hindered progress in understanding the dynamics of t-loop formation and its function in protecting chromosome ends. Here, we employed a classical two-dimensional agarose gel method (2D gel method) to innovatively apply to t-loop detection. Briefly, restriction fragments of genomic DNA were separated in a 2D gel, and the telomere sequence was detected by in-gel hybridization with telomeric probe. Using this method, we found that t-loops are present throughout the cell cycle, and t-loop formation tightly couples to telomere replication. We also observed that t-loop abundance positively correlates with chromatin condensation, i.e. cells with less compact telomeric chromatin (ALT cells and trichostatin A (TSA)-treated HeLa cells) exhibited fewer t-loops. Moreover, we observed that telomere dysfunction-induced foci, ALT-associated promyelocytic leukemia bodies, and telomere sister chromatid exchanges are activated upon TSA-induced loss of t-loops. These findings confirm the importance of the t-loop in protecting linear chromosomes from damage or illegitimate recombination.

References

May 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·D E Gottschling
Mar 1, 1991·Molecular and Cellular Biology·P J Krysan, M P Calos
Jan 1, 1995·Methods in Enzymology·K L Friedman, B J Brewer
Nov 14, 1997·Genes & Development·W E WrightJ W Shay
Feb 26, 1998·Cell·B van SteenselT de Lange
Feb 26, 1999·Science·J KarlsederT de Lange
May 25, 1999·Cell·J D GriffithT de Lange
Feb 7, 2001·The EMBO Journal·J L Muñoz-JordánJ D Griffith
Sep 27, 2001·Cell·E H Blackburn
Sep 28, 2001·The EMBO Journal·R M StanselJ D Griffith
Sep 29, 2001·Science·S M BaileyE H Goodwin
Feb 19, 2002·Oncogene·Titia de Lange
Aug 10, 2002·The EMBO Journal·Agata Smogorzewska, Titia de Lange
Sep 6, 2003·Current Biology : CB·Hiroyuki TakaiTitia de Lange
Oct 11, 2003·The Plant Journal : for Cell and Molecular Biology·Anthony J CesareJack D Griffith
Nov 20, 2003·Cellular and Molecular Life Sciences : CMLS·C Wei, M Price
Jul 14, 2004·The Journal of Cell Biology·Tatiana Nikitina, Christopher L Woodcock
Oct 29, 2004·Molecular and Cellular Biology·Anthony J Cesare, Jack D Griffith
Aug 11, 2005·Nucleic Acids Research·Sarit CohenDaniel Segal
Sep 10, 2005·PLoS Genetics·Marcela RaicesJan Karlseder
Sep 17, 2005·Genes & Development·Titia de Lange
Dec 13, 2005·Molecular Biology of the Cell·Rebecca L TomlinsonMichael P Terns
Jan 24, 2007·Nature Genetics·Roberta BenettiMaría A Blasco
Mar 17, 2007·Nature Reviews. Genetics·María A Blasco
Feb 14, 2009·The EMBO Journal·Hilda A PickettRoger R Reddel
Mar 31, 2010·Nature Reviews. Genetics·Anthony J Cesare, Roger R Reddel
May 5, 2012·Science·Agnel Sfeir, Titia de Lange
Dec 12, 2012·Frontiers in Oncology·Sarah Luke-GlaserBrian Luke
Jan 26, 2013·DNA Repair·Liana Oganesian, Jan Karlseder
Dec 12, 2013·Nature Reviews. Molecular Cell Biology·Stephanie Panier, Simon J Boulton
Feb 7, 2014·Nucleic Acids Research·Harikleia EpiskopouAnabelle Decottignies
Nov 20, 2015·Nature Structural & Molecular Biology·Hilda A Pickett, Roger R Reddel
Jun 16, 2017·EMBO Reports·Tianpeng ZhangYong Zhao

❮ Previous
Next ❯

Related Concepts

Related Feeds

ASBMB Publications

The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.