title: Optogenetic regulation of site-specific subtelomeric DNA methylation.
abstract: 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 single-molecule fluorescence analyses. Increased methylation was achieved selectively at subtelomeric CpG sites on the six examined chromosome ends specifically after blue-light 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.
authors.affiliation: Department of Agricultural & Biological Engineering, Bindley Bioscience Center, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Samrat Roy
authors.initials: SR
authors.lastname: Choudhury
authors.affiliation: Department of Agricultural & Biological Engineering, Bindley Bioscience Center, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Bindley Laboratory of Structural Biology, Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Anoop
authors.initials: A
authors.lastname: Narayanan
authors.affiliation: Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: David P
authors.initials: DP
authors.lastname: Gilley
authors.affiliation: Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Nazmul
authors.initials: N
authors.lastname: Huda
authors.affiliation: Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Chiao-Ling
authors.initials: CL
authors.lastname: Lo
authors.affiliation: Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.|Stark Institute of Neuroscience Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Feng C
authors.initials: FC
authors.lastname: Zhou
authors.affiliation: Bindley Laboratory of Structural Biology, Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Yernool
authors.affiliation: Department of Agricultural & Biological Engineering, Bindley Bioscience Center, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Irudayaraj
mesh_terms: D002135:Calcium-Binding Proteins / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry; D002875:Chromosomes / Q000648:ultrastructure; D018899:CpG Islands; D056931:Cryptochromes / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics*; D019175:DNA Methylation; D000090205:DNA Methyltransferase 3A; D044127:Epigenesis, Genetic; D006367:HeLa Cells; D006801:Humans; D062308:Optogenetics; D000072417:Protein Domains; D019098:Telomerase / Q000235:genetics; D016615:Telomere / Q000648:ultrastructure; D059505:Telomere Homeostasis; D035321:Telomeric Repeat Binding Protein 1 / Q000378:metabolism
chemical_list: C109198:CIB1 protein, human; C538966:CRY2 protein, human; D002135:Calcium-Binding Proteins; D002843:Chromatin; D056931:Cryptochromes; C000717967:DNMT3A protein, human; D035321:Telomeric Repeat Binding Protein 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D019098:Telomerase
keywords: optogenetics; single-cells tools; subtelomeric DNA-methylation; telomere-elongation