UBP1, a novel hnRNP-like protein that functions at multiple steps of higher plant nuclear pre-mRNA maturation
Efficient splicing of higher plant pre‐mRNAs depends on AU‐ or U‐rich sequences in introns. Moreover, AU‐rich sequences present in 3′‐untranslated regions (3′‐UTRs) may play a role in 3′ end processing of plant mRNAs. Here, we describe the cloning and characterization of a Nicotiana plumbaginifolia...
Gespeichert in:
Veröffentlicht in: | The EMBO journal 2000-04, Vol.19 (7), p.1638-1649 |
---|---|
Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Efficient splicing of higher plant pre‐mRNAs depends on AU‐ or U‐rich sequences in introns. Moreover, AU‐rich sequences present in 3′‐untranslated regions (3′‐UTRs) may play a role in 3′ end processing of plant mRNAs. Here, we describe the cloning and characterization of a
Nicotiana plumbaginifolia
nuclear protein that can be cross‐linked to U‐rich intron and 3′‐UTR sequences
in vitro
, and associates with nuclear poly(A)
+
RNA
in vivo
. The protein, UBP1, strongly enhances the splicing of otherwise inefficiently processed introns when overexpressed in protoplasts. It also increases the accumulation of reporter mRNAs that contain suboptimal introns or are intronless. The enhanced accumulation is apparently due to UBP1 interacting with the 3′‐UTR and protecting mRNA from exonucleolytic degradation. The effect on mRNA accumulation but not on mRNA splicing was found to be promoter specific. The fact that these effects of UBP1 can be separated suggests that they represent two independent activities. The properties of UBP1 indicate that it is an hnRNP protein that functions at multiple steps to facilitate the nuclear maturation of plant pre‐mRNAs. |
---|---|
ISSN: | 0261-4189 1460-2075 1460-2075 |
DOI: | 10.1093/emboj/19.7.1638 |