High impact information on rna1

• The distribution between the GTP- and GDP-bound forms of the protein is regulated by evolutionarily conserved gene products, rna1p and pim1p, functioning as GTPase-activating protein (GAP) and guanine nucleotide exchange factor (GEF), respectively [1].
• A loss of pim1p GEF activity or an increase in the rna1p GAP activity correlates with a change in the localization of the GTPase from predominantly nuclear to uniformly distributed, suggesting that the two forms are topologically segregated and that the nucleotide-bound state of spi1p may dictate its intracellular localization [1].
• By analyzing the RanGAP activity of a series of recombinantly expressed rna1p mutant derivatives, we show that the highly acidic sequence in the C-terminal domain of both yeast proteins is indispensable for activating Ran-mediated GTP hydrolysis [2].
• As the acidic C-terminal domain of rna1p is required for establishing the interaction with Ran, the leucine-rich repeats domain in rna1p is potentially available for additional protein interactions perhaps required for directing a fraction of rna1p to the nuclear pore [2].
• We identify a sequence motif of 29 residues, which is rich in leucine and repeated eight times both in S. pombe and in S. cerevisiae rna1p [3].

Analytical, diagnostic and therapeutic context of rna1

• Cell fractionation and immunofluorescence microscopy indicate that rna1p is a cytoplasmic protein possibly enriched in the nuclear periphery [3].

References