Rbl2p, a yeast protein that binds to beta-tubulin and participates in microtubule function in vivo.
Genetic configurations resulting in high ratios of beta-tubulin to alpha-tubulin are toxic in S. cerevisiae, causing microtubule disassembly and cell death. We identified three non-tubulin yeast genes that, when overexpressed, rescue cells from excess beta-tubulin. One, RBL2, rescues beta-tubulin lethality as efficiently as does alpha-tubulin. Rbl2p binds to beta-tubulin in vivo. Deficiencies or excesses of either Rbl2p or alpha-tubulin affect microtubule-dependent functions in a parallel fashion. Rbl2p has functional homology with murine cofactor A, a protein important for in vitro assays of beta-tubulin folding. The results suggest that Rbl2p participates in microtubule morphogenesis but not in the assembled polymer.
Archer
J E
JE
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
Vega
L R
LR
Solomon
F
F
D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000302:isolation & purification* / Q000502:physiology; D008870:Microtubules / Q000502:physiology*; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D016415:Sequence Alignment; D014404:Tubulin / Q000502:physiology*
D005656:Fungal Proteins; D014404:Tubulin