A genome-wide RNA interference screen reveals that variant histones are necessary for replication-dependent histone pre-mRNA processing.
Metazoan replication-dependent histone mRNAs are not polyadenylated and instead end in a conserved stem loop that is the cis element responsible for coordinate posttranscriptional regulation of these mRNAs. Using biochemical approaches, only a limited number of factors required for cleavage of histone pre-mRNA have been identified. We therefore performed a genome-wide RNA interference screen in Drosophila cells using a GFP reporter that is expressed only when histone pre-mRNA processing is disrupted. Four of the 24 genes identified encode proteins also necessary for cleavage/polyadenylation, indicating mechanistic conservation in formation of different mRNA 3' ends. We also unexpectedly identified the histone variants H2Av and H3.3A/B. In H2Av mutant cells, U7 snRNP remains active but fails to accumulate at the histone locus, suggesting there is a regulatory pathway that coordinates the production of variant and canonical histones that acts via localization of essential histone pre-mRNA processing factors.
Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Eric J
EJ
Wagner
Brandon D
BD
Burch
Ashley C
AC
Godfrey
Harmony R
HR
Salzler
Robert J
RJ
Duronio
William F
WF
Marzluff
D000818:Animals; D001483:Base Sequence; D004261:DNA Replication; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology; D017930:Genes, Reporter; D049750:Genome, Insect / Q000235:genetics*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism*; D026723:Polyadenylation; D021381:Protein Transport; D034622:RNA Interference; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D020885:Ribonucleoprotein, U7 Small Nuclear / Q000378:metabolism
D029721:Drosophila Proteins; D006657:Histones; D050505:Mutant Proteins; D012322:RNA Precursors; D020885:Ribonucleoprotein, U7 Small Nuclear