Histone H1 phosphorylation is associated with transcription by RNA polymerases I and II.
Histone H1 phosphorylation affects chromatin condensation and function, but little is known about how specific phosphorylations impact the function of H1 variants in higher eukaryotes. In this study, we show that specific sites in H1.2 and H1.4 of human cells are phosphorylated only during mitosis or during both mitosis and interphase. Antisera generated to individual H1.2/H1.4 interphase phosphorylations reveal that they are distributed throughout nuclei and enriched in nucleoli. Moreover, interphase phosphorylated H1.4 is enriched at active 45S preribosomal RNA gene promoters and is rapidly induced at steroid hormone response elements by hormone treatment. Our results imply that site-specific interphase H1 phosphorylation facilitates transcription by RNA polymerases I and II and has an unanticipated function in ribosome biogenesis and control of cell growth. Differences in the numbers, structure, and locations of interphase phosphorylation sites may contribute to the functional diversity of H1 variants.
Zheng
Yupeng
Y
Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
John
Sam
S
Pesavento
James J
JJ
Schultz-Norton
Jennifer R
JR
Schiltz
R Louis
RL
Baek
Sonjoon
S
Nardulli
Ann M
AM
Hager
Gordon L
GL
Kelleher
Neil L
NL
Mizzen
Craig A
CA
D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004275:DNA, Ribosomal / Q000378:metabolism; D016195:G2 Phase; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008856:Microscopy, Fluorescence; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012318:RNA Polymerase I / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D014158:Transcription, Genetic
D004275:DNA, Ribosomal; D006657:Histones; D012319:RNA Polymerase II; D012318:RNA Polymerase I