The small Ras-like GTPase Ran plays an essential role in the transport of macromolecules in and out of the nucleus and has been implicated in spindle and nuclear envelope formation during mitosis in higher eukaryotes. The S. cerevisiae ORF YGL164c encoding a novel RanGTP-binding protein, termed Yrb30p was identified. The protein competes with yeast RanBP1 (Yrb1p) for binding to the GTP-bound form of yeast Ran (Gsp1p) and is, like Yrb1p, able to form trimeric complexes with RanGTP and some of the karyopherins [1].

1: Identification and characterization of a novel RanGTP-binding protein in the yeast Saccharomyces cerevisiae. Braunwarth A, Fromont-Racine M, Legrain P, Bischoff FR, Gerstberger T, Hurt E, Kunzler M; J Biol Chem 2003;0:0-0. PMID:12578832