GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:19622636

From GONUTS
Jump to: navigation, search
Citation

Uemura, A, Oku, M, Mori, K and Yoshida, H (2009) Unconventional splicing of XBP1 mRNA occurs in the cytoplasm during the mammalian unfolded protein response. J. Cell. Sci. 122:2877-86

Abstract

XBP1 is a key transcription factor that regulates the mammalian unfolded protein response. Its expression is regulated by unconventional mRNA splicing that is carried out by endonuclease IRE1 and a specific, as yet unknown, RNA ligase in response to the accumulation of unfolded proteins in the ER. Conventional mRNA splicing occurs only in the nucleus, but it has remained unclear whether unconventional splicing of XBP1 mRNA takes place in the nucleus, cytoplasm or both. Here, we show that the catalytic domain of IRE1 contains a nuclear exclusion signal to prevent IRE1 from mislocalizing to the nucleus. In addition, RNA ligase, which joins XBP1 exons cleaved by IRE1 was detected in the cytoplasm but not in the nucleus. Moreover, the cytoplasm contained large amounts of unspliced XBP1 mRNA compared with the nucleus. Most unspliced XBP1 mRNA was converted to spliced mRNA by unconventional splicing even if de novo transcription was blocked, suggesting that cytoplasmic XBP1 mRNA, not nuclear XBP1 mRNA, is a major substrate for unconventional splicing. From these observations, we concluded that unconventional splicing of XBP1 mRNA occurs predominantly in the cytoplasm.

Links

PubMed Online version:10.1242/jcs.040584

Keywords

Amino Acid Sequence; Catalytic Domain; Cytoplasm/genetics; DNA-Binding Proteins/genetics; Endoribonucleases/chemistry; HeLa Cells; Humans; Intracellular Membranes/metabolism; Molecular Sequence Data; Nuclear Export Signals; Protein Folding; Protein-Serine-Threonine Kinases/chemistry; RNA Ligase (ATP); RNA Splicing/genetics; RNA, Messenger/genetics; RNA, Messenger/metabolism; Solubility; Subcellular Fractions/metabolism; Transcription Factors/genetics; Transcription, Genetic

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

HUMAN:ERN1

located_in

GO:0005737: cytoplasm

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:ERN1

part_of

GO:0005737: cytoplasm

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:ERN1

involved_in

GO:0033120: positive regulation of RNA splicing

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:ERN1

involved_in

GO:0070054: mRNA splicing, via endonucleolytic cleavage and ligation

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

Notes

See also

References

See Help:References for how to manage references in GONUTS.