SLBP is associated with histone mRNA on polyribosomes as a component of the histone mRNP.
The stem-loop binding protein (SLBP) binds the 3' end of histone mRNA and is present both in nucleus, and in the cytoplasm on the polyribosomes. SLBP participates in the processing of the histone pre-mRNA and in translation of the mature message. Histone mRNAs are rapidly degraded when cells are treated with inhibitors of DNA replication and are stabilized by inhibitors of translation, resulting in an increase in histone mRNA levels. Here, we show that SLBP is a component of the histone messenger ribonucleoprotein particle (mRNP). Histone mRNA from polyribosomes is immunoprecipitated with anti-SLBP. Most of the SLBP in cycloheximide-treated cells is present on polyribosomes as a result of continued synthesis and transport of the histone mRNP to the cytoplasm. When cells are treated with inhibitors of DNA replication, histone mRNAs are rapidly degraded but SLBP levels remain constant and SLBP is relocalized to the nucleus. SLBP remains active both in RNA binding and histone pre-mRNA processing when DNA replication is inhibited.
Whitfield
Michael L
ML
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.
Kaygun
Handan
H
Erkmann
Judith A
JA
Townley-Tilson
W H Davin
WH
Dominski
Zbigniew
Z
Marzluff
William F
WF
D000818:Animals; D016466:CHO Cells; D002467:Cell Nucleus / Q000737:chemistry; D006224:Cricetinae; D003412:Cricetulus; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication / Q000187:drug effects; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism*; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D011132:Polyribosomes / Q000378:metabolism*; D011233:Precipitin Tests; D012322:RNA Precursors / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins / Q000737:chemistry*; D014407:Tumor Cells, Cultured; D039221:mRNA Cleavage and Polyadenylation Factors / Q000032:analysis* / Q000276:immunology / Q000378:metabolism*
D006657:Histones; D009687:Nuclear Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; C092663:SLBP protein, human; C490494:Slbp protein, mouse; D039221:mRNA Cleavage and Polyadenylation Factors; C026452:messenger ribonucleoprotein; D004247:DNA; D003513:Cycloheximide