“…BUD1\RSR1 is essential for maintaining proper axial and bipolar budding polarity (Bender & Pringle, 1989 ;, as are its GTPaseactivating protein and guanine nucleotide exchange factor, Bud2p and Bud5p, respectively (Bender, 1993 ;Park et al, 1993 ;Powers et al, 1991). Further, an activated allele of the Bud1\Rsr1 GTPase fails to rescue the bud-site selection defects of a bud1\rsr1 deletion strain (Ruggieri et al, 1992).…”