Rolls, Stein, and colleagues (page 29) adapted a screening approach, which had previously been used only in yeast, to identify novel nuclear envelope proteins in mammalian cells. This technique could have a wide range of applications in cell biology and proteomics. The screen, which involves cloning a library of mammalian cDNA sequences into an expression vector with a green fluorescent protein (GFP) tag, allows the cloning of genes whose products have specific intracellular localization patterns. Cells are transformed with pools of cDNA-carrying plasmids, and sib selection allows enrichment of pools that show a desired pattern of fluorescence.
After demonstrating that known proteins localized correctly in the assay when fused to GFP, the team screened half of a cDNA library for novel nuclear envelope proteins. The screen uncovered a multiple membrane-spanning protein, subsequently named nurim, which is targeted to the...
