Cold stress-induced protein Rbm3 binds 60S ribosomal subunits, alters microRNA levels, and enhances global protein synthesis

• DOI: 10.1073/pnas.0409764102
• Publication Date: 2005-02-01T01:24:43Z
• Authors: John Dresios; Armaz Aschrafi; Geoffrey C. Owens; Peter W. Vanderklish; Gerald M. Edelman; Vincent P. Mauro
• Keywords: Ribosomal protein; Stress granule

The expression of Rbm3, a glycine-rich RNA-binding protein, is enhanced under conditions mild hypothermia, and Rbm3 has been postulated to facilitate protein synthesis at colder temperatures. To investigate this possibility, was overexpressed as c-Myc fusion in mouse neuroblastoma N2a cells. Cells expressing showed 3-fold increase both 37°C 32°C compared with control Although polysome profiles cells the were similar, several differences noted, suggesting that might enhance association 40S 60S ribosomal subunits 32°C. Studies assess direct interaction ribosomes fraction associated an RNA-independent manner. It appeared unlikely could explain global enhancement synthesis, however, because no substantial size their monosome peaks, similar numbers mRNAs being translated approximately same rates. In contrast, complex sedimented between top gradient less abundant recombinant Rbm3. Further analysis RNA component microRNA. We discuss possibility alters by affecting microRNA levels suggest microRNAs are part homeostatic mechanism regulates normal cold-stress conditions.