Chromatin decondensation is accompanied by a transient increase in transcriptional output

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F17%3A10366988" target="_blank" >RIV/00216208:11310/17:10366988 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11110/17:10366988

Výsledek na webu

<a href="http://dx.doi.org/10.1111/boc.201600032" target="_blank" >http://dx.doi.org/10.1111/boc.201600032</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/boc.201600032" target="_blank" >10.1111/boc.201600032</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Chromatin decondensation is accompanied by a transient increase in transcriptional output

Popis výsledku v původním jazyce

The levels of chromatin condensation usually correlate inversely with the levels of transcription. The mechanistic links between chromatin condensation and RNA polymerase II activity remain to be elucidated. In the present work, we sought to experimentally determine whether manipulation of chromatin condensation levels can have a direct effect on transcriptional activity. ResultsWe generated a U-2-OS cell line in which the nascent transcription of a reporter gene could be imaged alongside chromatin compaction levels in living cells. The transcripts were tagged at their 5 end with PP7 stem loops, which can be detected upon expression of a PP7 capsid protein fused to green fluorescent protein. Cycles of global chromatin hypercondensation and decondensation were performed by perfusing culture media of different osmolarities during imaging. We used the fluorescence recovery after photobleaching technique to analyse the transcriptional dynamics in both conditions. Surprisingly, we found that, despite a drop in signal intensity, nascent transcription appeared to continue at the same rate in hypercondensed chromatin. Furthermore, quantification of transcriptional profiles revealed that chromatin decondensation was accompanied by a brief and transient spike in transcriptional output. ConclusionsWe propose a model whereby the initiation of transcription is not impaired in condensed chromatin, but inefficient elongation in these conditions leads to the accumulation of RNA polymerase II at the transcription site. Upon chromatin decondensation, release of the RNA polymerase II halt triggers a wave of transcription, which we detect as a transient spike in activity. SignificanceThe results presented here shed light on the activity of RNA polymerase II during chromatin condensation and decondensation. As such, they point to a new level of transcriptional regulation.

Název v anglickém jazyce

Chromatin decondensation is accompanied by a transient increase in transcriptional output

Popis výsledku anglicky

The levels of chromatin condensation usually correlate inversely with the levels of transcription. The mechanistic links between chromatin condensation and RNA polymerase II activity remain to be elucidated. In the present work, we sought to experimentally determine whether manipulation of chromatin condensation levels can have a direct effect on transcriptional activity. ResultsWe generated a U-2-OS cell line in which the nascent transcription of a reporter gene could be imaged alongside chromatin compaction levels in living cells. The transcripts were tagged at their 5 end with PP7 stem loops, which can be detected upon expression of a PP7 capsid protein fused to green fluorescent protein. Cycles of global chromatin hypercondensation and decondensation were performed by perfusing culture media of different osmolarities during imaging. We used the fluorescence recovery after photobleaching technique to analyse the transcriptional dynamics in both conditions. Surprisingly, we found that, despite a drop in signal intensity, nascent transcription appeared to continue at the same rate in hypercondensed chromatin. Furthermore, quantification of transcriptional profiles revealed that chromatin decondensation was accompanied by a brief and transient spike in transcriptional output. ConclusionsWe propose a model whereby the initiation of transcription is not impaired in condensed chromatin, but inefficient elongation in these conditions leads to the accumulation of RNA polymerase II at the transcription site. Upon chromatin decondensation, release of the RNA polymerase II halt triggers a wave of transcription, which we detect as a transient spike in activity. SignificanceThe results presented here shed light on the activity of RNA polymerase II during chromatin condensation and decondensation. As such, they point to a new level of transcriptional regulation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10600 - Biological sciences

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Biology of the Cell

ISSN

0248-4900

e-ISSN

—

Svazek periodika

109

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

15

Strana od-do

65-79

Kód UT WoS článku

000392489900004

EID výsledku v databázi Scopus

2-s2.0-84995618190