Toward an assembly line for U7 snRNPs: interactions of U7-specific Lsm proteins with PRMT5 and SMN complexes.

Azzouz, Teldja N.; Pillai, Ramesh S.; Däpp, Christoph; Chari, Ashwin; Meister, Gunter; Kambach, Christian; Fischer, Utz; Schümperli, Daniel (2005). Toward an assembly line for U7 snRNPs: interactions of U7-specific Lsm proteins with PRMT5 and SMN complexes. Journal of biological chemistry, 280(41), pp. 34435-34440. American Society for Biochemistry and Molecular Biology 10.1074/jbc.M505077200

Text schümperli_däpp.pdf - Published Version Restricted to registered users only Available under License Publisher holds Copyright. Download (756kB)

The survival of motor neurons (SMN) complex mediates the assembly of small nuclear ribonucleoproteins (snRNPs) involved in splicing and histone RNA processing. A crucial step in this process is the binding of Sm proteins onto the SMN protein. For Sm B/B', D1, and D3, efficient binding to SMN depends on symmetrical dimethyl arginine (sDMA) modifications of their RG-rich tails. This methylation is achieved by another entity, the PRMT5 complex. Its pICln subunit binds Sm proteins whereas the PRMT5 subunit catalyzes the methylation reaction. Here, we provide evidence that Lsm10 and Lsm11, which replace the Sm proteins D1 and D2 in the histone RNA processing U7 snRNPs, associate with pICln in vitro and in vivo without receiving sDMA modifications. This implies that the PRMT5 complex is involved in an early stage of U7 snRNP assembly and hence may have a second snRNP assembly function unrelated to sDMA modification. We also show that the binding of Lsm10 and Lsm11 to SMN is independent of any methylation activity. Furthermore, we present evidence for two separate binding sites in SMN for Sm/Lsm proteins. One recognizes Sm domains and the second one, the sDMA-modified RG-tails, which are present only in a subset of these proteins.

Interest & Impact

Downloads

13 since deposited on 22 Aug 2014
0 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item