Optogenetic regulation of site-specific subtelomeric DNA-methylation

Samrat Roy Choudhury, Yi Cui, Anoop Narayanan, David P. Gilley, Nazmul Huda, Chiao Ling Lo, Feng C. Zhou, Dinesh Yernool, Joseph Irudayaraj

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Telomere length homeostasis, critical for chromosomal integrity and genome stability, is controlled by intricate molecular regulatory machinery that includes epigenetic modifications. Here, we examine site-specific and spatiotemporal alteration of the subtelomeric methylation of CpG islands using optogenetic tools to understand the epigenetic regulatory mechanisms of telomere length maintenance. Human DNA methyltransferase3A (DNMT3A) were assembled selectively at chromosome ends by fusion to cryptochrome 2 protein (CRY2) and its interacting complement, the basic helix loop helix protein-1 (CIB1). CIB1 was fused to the telomere-associated protein telomere repeat binding factor-1 (TRF1), which localized the protein complex DNMT3A-CRY2 at telomeric regions upon excitation by blue-light monitored by singlemolecule fluorescence analyses. Increased methylation was achieved selectively at subtelomeric CpG sites on the six examined chromosome ends specifically after bluelight activation, which resulted in progressive increase in telomere length over three generations of HeLa cell replications. The modular design of the fusion constructs presented here allows for the selective substitution of other chromatin modifying enzymes and for loci-specific targeting to regulate the epigenetic pathways at telomeres and other selected genomic regions of interest.

Original languageEnglish (US)
Pages (from-to)50380-50391
Number of pages12
Issue number31
StatePublished - 2016

All Science Journal Classification (ASJC) codes

  • Oncology


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