The polyribosomal protein bound to the 3' end of histone mRNA can function in histone pre-mRNA processing.
Cell cycle-regulated histone mRNAs end in a conserved 26-nt sequence that can form a stem-loop with a six-base stem and a four-base loop. The 3' end of histone mRNA has distinct functions in the nucleus and in the cytoplasm. In the nucleus it functions in pre-mRNA processing and transport, whereas in the cytoplasm it functions in translation and regulation of histone mRNA stability. The stem-loop binding protein (SLBP), present in both nuclei and polyribosomes, is likely the trans-acting factor that binds to the 3' end of mature histone mRNA and mediates its function. A nuclear extract that efficiently processes histone pre-mRNA was prepared from mouse myeloma cells. The factor(s) that bind to the 3' end of histone mRNA can be depleted from this extract using a biotinylated oligonucleotide containing the conserved stem-loop sequence. Using this depleted extract which is deficient in histone pre-mRNA processing, we show that SLBP found in polyribosomes can restore processing, suggesting that SLBP associates with histone pre-mRNA in the nucleus, participates in processing, and then accompanies the mature mRNA to the cytoplasm.
Dominski
Z
Z
Department of Biochemistry, University of North Carolina, Chapel Hill 27599, USA.
Sumerel
J
J
Hanson
R J
RJ
Marzluff
W F
WF
D000818:Animals; D001483:Base Sequence; D001710:Biotin / Q000737:chemistry; D002457:Cell Extracts / Q000737:chemistry; D002467:Cell Nucleus / Q000235:genetics; D002478:Cells, Cultured; D017124:Conserved Sequence; D006657:Histones / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000473:pathology; D009687:Nuclear Proteins; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism; D011132:Polyribosomes / Q000235:genetics*; D012322:RNA Precursors; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D039221:mRNA Cleavage and Polyadenylation Factors
D002457:Cell Extracts; D006657:Histones; D009687:Nuclear Proteins; D009841:Oligonucleotides; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear; C490494:Slbp protein, mouse; D039221:mRNA Cleavage and Polyadenylation Factors; D001710:Biotin