Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für biophysikalische Chemie     Collection: Zelluläre Biochemie (Prof. Reinhard Lührmann)     Display Documents

ID: 17159.0, MPI für biophysikalische Chemie / Zelluläre Biochemie (Prof. Reinhard Lührmann)
The human LSm1-7 proteins colocalize with the mRNA-degrading enzymes Dcp1/2 and Xrn1 in distinct cytoplasmic foci
Authors:Ingelfinger, D.; Arndt-Jovin, D. J.; Luehrmann, R.; Achsel, T.
Date of Publication (YYYY-MM-DD):2002-12
Title of Journal:RNA-A Publication of the RNA Society
Issue / Number:12
Start Page:1489
End Page:1501
Review Status:Peer-review
Audience:Not Specified
Abstract / Description:Sm and Sm-like (LSm) proteins form heptameric complexes that are involved in various steps of RNA metabolism. In yeast, the Lsm1-7 complex functions in mRNA degradation and is associated with several enzymes of this pathway, while the complex LSm2-8, the composition of which largely overlaps with that of LSm1-7, has a role in pre-mRNA splicing. A human gene encoding an LSm1 homolog has been identified, but its role in mRNA degradation has yet to be elucidated. We performed subcellular localization studies and found hLSm1 predominantly in the cytoplasm. However, it is not distributed evenly; rather, it is highly enriched in small, discrete foci. The endogenous hLSm4 is similarly localized, as are the overexpressed proteins hLSm1-7, but not hLSm8. The foci also contain two key factors in mRNA degradation, namely the decapping enzyme hDcp1/2 and the exonuclease hXrn1. Moreover, coexpression of wild-type and mutant LSm proteins, as well as fluorescence resonance energy transfer (FRET) studies, indicate that the mammalian proteins hLSm1-7 form a complex similar to the one found in yeast, and that complex formation is required for enrichment of the proteins in the cytoplasmic foci. Therefore, the foci contain a partially or fully assembled machinery for the degradation of mRNA.
Free Keywords:exoribonucleases; messenger RNA; ribonucleoproteins; RNA caps
Comment of the Author/Creator:Date: 2002, DEC
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für biophysikalische Chemie/Abt. Reinhard Lührmann / 100
MPI für biophysikalische Chemie/Abt. Thomas Jovin / 060/AG Donna Arndt-Jovin
External Affiliations:Fondaz Santa Lucia, Via Ardeatina 354, I-00179 Rome, Italy
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.