Changes in the stem-loop at the 3' terminus of histone mRNA affects its nucleocytoplasmic transport and cytoplasmic regulation.
The stem-loop structure at the 3' end of replication-dependent histone mRNA is required for efficient pre-mRNA processing, localization of histone mRNA to the polyribosomes, and regulation of histone mRNA degradation. A protein, the stem-loop binding protein (SLBP), binds the 3' end of histone mRNA and is thought to mediate some or all of these processes. A mutant histone mRNA with two nucleotide changes in the loop was constructed and found to be transported inefficiently to the cytoplasm. The mutant histone mRNA, unlike the wild-type histone mRNA, was not rapidly degraded when DNA synthesis is inhibited, and was not stabilized upon inhibition of protein synthesis. The stem-loop binding protein (SLBP) has between a 20-50 fold greater affinity for the wild type histone stem-loop structure than for the mutant stem-loop structure, suggesting that the alteration in the efficiency of transport and the normal degradation pathway in histone mRNA may be due to the reduced affinity of the mutant stem-loop for the SLBP.
Williams
A S
AS
Program in Molecular Biology and Biotechnology, University of North Carolina, Chapel Hill 27599.
Ingledue
T C
TC
Kay
B K
BK
Marzluff
W F
WF
D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D016466:CHO Cells; D017124:Conserved Sequence; D006224:Cricetinae; D003593:Cytoplasm / Q000378:metabolism*; D006657:Histones / Q000737:chemistry* / Q000235:genetics; D051379:Mice; D008845:Microinjections; D008969:Molecular Sequence Data; D009154:Mutation / Q000502:physiology; D009690:Nucleic Acid Conformation; D009865:Oocytes; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D014162:Transfection; D014981:Xenopus
D006657:Histones; D012333:RNA, Messenger; D016601:RNA-Binding Proteins