RNAi knockdown of hPrp31 leads to an accumulation of U4/U6 di-snRNPs in Cajal bodies
- 15 July 2004
- journal article
- Published by Springer Science and Business Media LLC in The EMBO Journal
- Vol. 23 (15), 3000-3009
- https://doi.org/10.1038/sj.emboj.7600296
Abstract
Cajal bodies (CBs) are subnuclear organelles of animal and plant cells. A role of CBs in the assembly and maturation of small nuclear ribonucleoproteins (snRNP) has been proposed but is poorly understood. Here we have addressed the question where U4/U6.U5 tri‐snRNP assembly occurs in the nucleus. The U4/U6.U5 tri‐snRNP is a central unit of the spliceosome and must be re‐formed from its components after each round of splicing. By combining RNAi and biochemical methods, we demonstrate that, after knockdown of the U4/U6‐specific hPrp31 (61 K) or the U5‐specific hPrp6 (102 K) protein in HeLa cells, tri‐snRNP formation is inhibited and stable U5 mono‐snRNPs and U4/U6 di‐snRNPs containing U4/U6 proteins and the U4/U6 recycling factor p110 accumulate. Thus, hPrp31 and hPrp6 form an essential connection between the U4/U6 and U5 snRNPs in vivo . Using fluorescence microscopy, we show that, in the absence of either hPrp31 or hPrp6, U4/U6 di‐snRNPs as well as p110 accumulate in Cajal bodies. In contrast, U5 snRNPs largely remain in nucleoplasmic speckles. Our data support the idea that CBs may play a role in tri‐snRNP recycling.Keywords
This publication has 49 references indexed in Scilit:
- The centennial of the Cajal bodyNature Reviews Molecular Cell Biology, 2003
- Nuclear speckles: a model for nuclear organellesNature Reviews Molecular Cell Biology, 2003
- Cajal bodies and coilin—moving towards functionThe Journal of cell biology, 2002
- p110, a novel human U6 snRNP protein and U4/U6 snRNP recycling factorThe EMBO Journal, 2002
- Central Region of the Human Splicing Factor Hprp3p Interacts with Hprp4pPublished by Elsevier BV ,2002
- Analysis of gene function in somatic mammalian cells using small interfering RNAsMethods, 2002
- The human homologue of the yeast splicing factor prp6p contains multiple TPR elements and is stably associated with the U5 snRNP via protein-protein interactionsJournal of Molecular Biology, 2000
- Differential interaction of splicing snRNPs with coiled bodies and interchromatin granules during mitosis and assembly of daughter cell nuclei.The Journal of cell biology, 1994
- Disruption of pre-mRNA splicing in vivo results in reorganization of splicing factorsThe Journal of cell biology, 1994
- In vitro reconstitution of snRNPs: a reconstituted U4/U6 snRNP participates in splicing complex formation.Genes & Development, 1989