TY - JOUR
T1 - The preRC protein ORCA organizes heterochromatin by assembling histone H3 lysine 9 methyltransferases on chromatin
AU - Giri, Sumanprava
AU - Aggarwal, Vasudha
AU - Pontis, Julien
AU - Shen, Zhen
AU - Chakraborty, Arindam
AU - Khan, Abid
AU - Mizzen, Craig Andrew
AU - Prasanth, Kannanganattu V.
AU - Ait-Si-Ali, Slimane
AU - Ha, Taekjip
AU - Prasanth, Supriya G.
N1 - Publisher Copyright:
© 2015, eLife Sciences Publications Ltd. All rights reserved.
PY - 2015/4/29
Y1 - 2015/4/29
N2 - Heterochromatic domains are enriched with repressive histone marks, including histone H3lysine 9 methylation, written by lysine methyltransferases (KMTs). The pre-replication complex protein Origin Recognition Complex-Associated (ORCA/LRWD1) preferentially localizes to heterochromatic regions in post-replicated cells. Its role in heterochromatin organization remained elusive. ORCA recognizes methylated H3K9 marks and interacts with repressive KMTs, including G9a/GLP and Suv39H1 in a chromatin context-dependent manner. Single33 molecule pull-down assays demonstrate that ORCA-ORC and multiple H3K9 KMTs exist in a single complex and that ORCA stabilizes H3K9 KMT complex. Cells lacking ORCA show alterations in chromatin architecture, with significantly reduced H3K9 di- and tri-methylation at specific chromatin sites. Changes in heterochromatin structure due to loss of ORCA affects replication timing, preferentially at the late-replicating regions. We demonstrate that ORCA acts as a scaffold for the establishment of H3K9 KMT complex and its association and activity at specific chromatin sites is crucial for the organization of heterochromatin structure.
AB - Heterochromatic domains are enriched with repressive histone marks, including histone H3lysine 9 methylation, written by lysine methyltransferases (KMTs). The pre-replication complex protein Origin Recognition Complex-Associated (ORCA/LRWD1) preferentially localizes to heterochromatic regions in post-replicated cells. Its role in heterochromatin organization remained elusive. ORCA recognizes methylated H3K9 marks and interacts with repressive KMTs, including G9a/GLP and Suv39H1 in a chromatin context-dependent manner. Single33 molecule pull-down assays demonstrate that ORCA-ORC and multiple H3K9 KMTs exist in a single complex and that ORCA stabilizes H3K9 KMT complex. Cells lacking ORCA show alterations in chromatin architecture, with significantly reduced H3K9 di- and tri-methylation at specific chromatin sites. Changes in heterochromatin structure due to loss of ORCA affects replication timing, preferentially at the late-replicating regions. We demonstrate that ORCA acts as a scaffold for the establishment of H3K9 KMT complex and its association and activity at specific chromatin sites is crucial for the organization of heterochromatin structure.
KW - Heterochromatin
KW - Lysine methyl transferase
KW - ORCA/LRWD1
KW - Single molecule pull down and replication
UR - http://www.scopus.com/inward/record.url?scp=84929145918&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84929145918&partnerID=8YFLogxK
U2 - 10.7554/eLife.06496
DO - 10.7554/eLife.06496
M3 - Article
C2 - 25922909
AN - SCOPUS:84929145918
VL - 2015
SP - 1
EP - 54
JO - eLife
JF - eLife
SN - 2050-084X
IS - 4
M1 - e06496
ER -