Formation of the 3' end of histone mRNA.
All metazoan messenger RNAs, with the exception of the replication-dependent histone mRNAs, terminate at the 3' end with a poly(A) tail. Replication-dependent histone mRNAs end instead in a conserved 26-nucleotide sequence that contains a 16-nucleotide stem-loop. Formation of the 3' end of histone mRNA occurs by endonucleolytic cleavage of pre-mRNA releasing the mature mRNA from the chromatin template. Cleavage requires several trans-acting factors, including a protein, the stem-loop binding protein (SLBP), which binds the 26-nucleotide sequence; and a small nuclear RNP, U7 snRNP. There are probably additional factors also required for cleavage. One of the functions of the SLBP is to stabilize binding of the U7 snRNP to the histone pre-mRNA. In the nucleus, both U7 snRNP and SLBP are present in coiled bodies, structures that are associated with histone genes and may play a direct role in histone pre-mRNA processing in vivo. One of the major regulatory events in the cell cycle is regulation of histone pre-mRNA processing, which is at least partially mediated by cell-cycle regulation of the levels of the SLBP protein.
Dominski
Z
Z
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill 27599, USA.
Marzluff
W F
WF
D020413:3' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D006657:Histones / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D020885:Ribonucleoprotein, U7 Small Nuclear / Q000378:metabolism; D039221:mRNA Cleavage and Polyadenylation Factors
D020413:3' Untranslated Regions; D006657:Histones; D009687:Nuclear Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D020885:Ribonucleoprotein, U7 Small Nuclear; C092663:SLBP protein, human; D039221:mRNA Cleavage and Polyadenylation Factors