Yejun Wang - Academia.edu (original) (raw)
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Papers by Yejun Wang
Scientific Reports, 2014
Remodeling of the local chromatin structure is essential for the regulation of gene expression. W... more Remodeling of the local chromatin structure is essential for the regulation of gene expression. While a number of biochemical and bioimaging experiments suggest decondensed chromatin structures are associated with transcription, a direct visualization of DNA and transcriptionally active RNA polymerase II (RNA pol II) at super-resolution is still lacking. Here we investigate the structure of chromatin isolated from HeLa cells using binding activatable localization microscopy (BALM). The sample preparation method preserved the structural integrity of chromatin. Interestingly, BALM imaging of the chromatin spreads revealed the presence of decondensed chromatin as gap structures along the spreads. These gaps were enriched with phosphorylated S5 RNA pol II, and were sensitive to the cellular transcriptional state. Taken together, we could visualize the decondensed chromatin regions together with active RNA pol II for the first time using super-resolution microscopy. E ukaryotic DNA is packaged, together with histones and non-histone proteins, into chromatin fibers 1,2 . The fundamental unit of this fiber is the nucleosome 3 , which consists of ,150 base pairs of DNA wrapped 1.6 times around an octamer of core histones (H2A, H2B, H3, H4) and sealed with a single linker histone (H1) molecule that is bound closely to the core particle dyad 4,5 . In interphase cells, chromatin fibers are further packed into higher order structures composed of euchromatin and heterochromatin 6 . Euchromatin is mostly comprised of active genes and gene-rich regions, while repressive DNA is usually heterochromatinized 7 . The various levels of DNA packaging are mediated by a number of post-translational modifications on both core and linker histones .
Scientific Reports, 2014
Remodeling of the local chromatin structure is essential for the regulation of gene expression. W... more Remodeling of the local chromatin structure is essential for the regulation of gene expression. While a number of biochemical and bioimaging experiments suggest decondensed chromatin structures are associated with transcription, a direct visualization of DNA and transcriptionally active RNA polymerase II (RNA pol II) at super-resolution is still lacking. Here we investigate the structure of chromatin isolated from HeLa cells using binding activatable localization microscopy (BALM). The sample preparation method preserved the structural integrity of chromatin. Interestingly, BALM imaging of the chromatin spreads revealed the presence of decondensed chromatin as gap structures along the spreads. These gaps were enriched with phosphorylated S5 RNA pol II, and were sensitive to the cellular transcriptional state. Taken together, we could visualize the decondensed chromatin regions together with active RNA pol II for the first time using super-resolution microscopy. E ukaryotic DNA is packaged, together with histones and non-histone proteins, into chromatin fibers 1,2 . The fundamental unit of this fiber is the nucleosome 3 , which consists of ,150 base pairs of DNA wrapped 1.6 times around an octamer of core histones (H2A, H2B, H3, H4) and sealed with a single linker histone (H1) molecule that is bound closely to the core particle dyad 4,5 . In interphase cells, chromatin fibers are further packed into higher order structures composed of euchromatin and heterochromatin 6 . Euchromatin is mostly comprised of active genes and gene-rich regions, while repressive DNA is usually heterochromatinized 7 . The various levels of DNA packaging are mediated by a number of post-translational modifications on both core and linker histones .