Expression of metazoan replication-dependent histone genes.
Histone proteins are essential components of eukaryotic chromosomes. In metazoans, they are produced from the so-called replication-dependent histone genes. The biogenesis of histones is tightly coupled to DNA replication in a stoichiometric manner because an excess of histones is highly toxic for the cell. Therefore, a strict cell cycle-regulation of critical factors required for histone expression ensures exclusive S-phase expression. This review focuses on the molecular mechanisms responsible for such a fine expression regulation. Among these, a large part will be dedicated to post-transcriptional events occurring on histone mRNA, like histone mRNA 3' end processing, nucleo-cytoplasmic mRNA export, translation and mRNA degradation. Many factors are involved, including an RNA-binding protein called HBP, also called SLBP (for hairpin- or stem-loop-binding protein) that binds to a conserved hairpin located in the 3' UTR part of histone mRNA. HBP plays a pivotal role in the expression of histone genes since it is necessary for most of the steps of histone mRNA metabolism in the cell. Moreover, the strict S-phase expression pattern of histones is achieved through a fine cell cycle-regulation of HBP. A large part of the discussion will be centered on the critical role of HBP in histone biogenesis.
Jaeger
Sophie
S
Département Mécanismes et Macromolécules de la Synthèse Protéique et Cristallogenèse, UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, 15, rue René Descartes, 67084 Strasbourg cedex, France.
Barends
Sharief
S
Giegé
Richard
R
Eriani
Gilbert
G
Martin
Franck
F
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle; D004261:DNA Replication; D005786:Gene Expression Regulation; D006657:Histones / Q000096:biosynthesis / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016196:S Phase; D014158:Transcription, Genetic
D006657:Histones; D012333:RNA, Messenger