A cellular protein binds B1 and Alu small cytoplasmic RNAs in vitro.

摘要: B1 and Alu are sequence-homologous interspersed elements of unknown function that have expanded in the genomes mice humans, respectively. A minority sequences expressed as small cytoplasmic RNAs. These RNAs conserved a secondary structure motif also present signal recognition particle (SRP) RNA despite substantial sequence divergence, whereas random not. This has been by source gave rise to successive transpositions during evolution. In work synthesized vitro were found bind cellular protein mobility shift UV cross-linking analyses. The mouse human proteins demonstrate same specificity panel competitor Results using mutated indicate single strand loop is essential for binding. Previous Strub et al. (Stub, K., Moss, J. B., Walter, P. (1991) Mol. Cell. Biol. 11, 3949-3959) demonstrated Alu-specific SRP 9/14 does not footprint this region RNA. observation coupled with failure anti-SRP/9 antibodies identify RNA-protein complex well apparent mass other characteristics described here suggest it novel B1-Alu RNA-binding protein. Conservation primary features their specific expression ability interact binding these more homologous than previously appreciated.