Although two Enhancer of Polycomb-like proteins,EPL1 A and EPL1 B(EPL1 A/B),are known to be conserved and characteristic subunits of the Nu A4-type histone acetyltransferase complex in Arabidopsis thaliana,the biologi...Although two Enhancer of Polycomb-like proteins,EPL1 A and EPL1 B(EPL1 A/B),are known to be conserved and characteristic subunits of the Nu A4-type histone acetyltransferase complex in Arabidopsis thaliana,the biological function of EPL1 A/B and the mechanism by which EPL1 A/B function in the complex remain unknown.Here,we report that EPL1 A/B are required for the histone acetyltransferase activity of the Nu A4 complex on the nucleosomal histone H4 in vitro and for the enrichment of histone H4 K5 acetylation at thousands of protein-coding genes in vivo.Our results suggest that EPL1 A/B are required for linking the Nu A4 catalytic subunits HISTONE ACETYLTRANSFERASE OF THE MYST FAMILY 1(HAM1)and HAM2 with accessory subunits in the Nu A4 complex.EPL1 A/B function redundantly in regulating plant development especially in chlorophyll biosynthesis and de-etiolation.The EPL1 A/B-dependent transcription and H4 K5 Ac are enriched at genes involved in chlorophyll biosynthesis and photosynthesis.We also find that EAF6,another characteristic subunit of the Nu A4 complex,contributes to de-etiolation.These results suggest that the Arabidopsis Nu A4 complex components function as a whole to mediate histone acetylation and transcriptional activation specifically at light-responsive genes and are critical for photomorphogenesis.展开更多
Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes.However,the deubiquitinase responsible for genome-...Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes.However,the deubiquitinase responsible for genome-wide H2A deubiquitination in plants has yet to be identified.In this study,we found that the previously identified PWWP-EPCR-ARID-TRB(PEAT)complex components interact with both the ubiquitin-specific protease UBP5 and the redundant histone acetyltransferases HAM1 and HAM2(HAM1/2)to form a larger version of PEAT complex in Arabidopsis thaliana.UBP5 functions as an H2A deubiquitinase in a nucleosome substrate-dependent manner in vitro and mediates H2A deubiquitination at the whole-genome level in vivo.HAM1/2 are shared subunits of the PEAT complex and the conserved NuA4 histone acetyltransferase com-plex,and are responsible for histone H4K5 acetylation.Within the PEAT complex,the PWWP components(PWWP1,PWWP2,and PWWP3)directly interact with UBP5 and are necessary for UBP5-mediated H2A deu-biquitination,while the EPCR components(EPCR1 and EPCR2)directly interact with HAM1/2 and are required for HAM1/2-mediated H4K5acetylation.Collectively,our study not onlyidentifies dual roles of thePEAT com-plex in H2A deubiquitination and H4K5 acetylation but also illustrates how these processes collaborate at the whole-genome level to regulate the transcription and development in plants.展开更多
基金supported by the National Natural Science Foundation of China(32025003)the National Key Research and Development Program of China(2016YFA0500801)from the Chinese Ministry of Science and Technology。
文摘Although two Enhancer of Polycomb-like proteins,EPL1 A and EPL1 B(EPL1 A/B),are known to be conserved and characteristic subunits of the Nu A4-type histone acetyltransferase complex in Arabidopsis thaliana,the biological function of EPL1 A/B and the mechanism by which EPL1 A/B function in the complex remain unknown.Here,we report that EPL1 A/B are required for the histone acetyltransferase activity of the Nu A4 complex on the nucleosomal histone H4 in vitro and for the enrichment of histone H4 K5 acetylation at thousands of protein-coding genes in vivo.Our results suggest that EPL1 A/B are required for linking the Nu A4 catalytic subunits HISTONE ACETYLTRANSFERASE OF THE MYST FAMILY 1(HAM1)and HAM2 with accessory subunits in the Nu A4 complex.EPL1 A/B function redundantly in regulating plant development especially in chlorophyll biosynthesis and de-etiolation.The EPL1 A/B-dependent transcription and H4 K5 Ac are enriched at genes involved in chlorophyll biosynthesis and photosynthesis.We also find that EAF6,another characteristic subunit of the Nu A4 complex,contributes to de-etiolation.These results suggest that the Arabidopsis Nu A4 complex components function as a whole to mediate histone acetylation and transcriptional activation specifically at light-responsive genes and are critical for photomorphogenesis.
基金supported by the National Natural Science Foundation of China(grant number:32025003).
文摘Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes.However,the deubiquitinase responsible for genome-wide H2A deubiquitination in plants has yet to be identified.In this study,we found that the previously identified PWWP-EPCR-ARID-TRB(PEAT)complex components interact with both the ubiquitin-specific protease UBP5 and the redundant histone acetyltransferases HAM1 and HAM2(HAM1/2)to form a larger version of PEAT complex in Arabidopsis thaliana.UBP5 functions as an H2A deubiquitinase in a nucleosome substrate-dependent manner in vitro and mediates H2A deubiquitination at the whole-genome level in vivo.HAM1/2 are shared subunits of the PEAT complex and the conserved NuA4 histone acetyltransferase com-plex,and are responsible for histone H4K5 acetylation.Within the PEAT complex,the PWWP components(PWWP1,PWWP2,and PWWP3)directly interact with UBP5 and are necessary for UBP5-mediated H2A deu-biquitination,while the EPCR components(EPCR1 and EPCR2)directly interact with HAM1/2 and are required for HAM1/2-mediated H4K5acetylation.Collectively,our study not onlyidentifies dual roles of thePEAT com-plex in H2A deubiquitination and H4K5 acetylation but also illustrates how these processes collaborate at the whole-genome level to regulate the transcription and development in plants.
