Role of Actin and Myo2p in Polarized Secretion and Growth of Saccharomyces cerevisiaeV⃞
AUTOR(ES)
Karpova, Tatiana S.
FONTE
The American Society for Cell Biology
RESUMO
We examined the role of the actin cytoskeleton in secretion in Saccharomyces cerevisiae with the use of several quantitative assays, including time-lapse video microscopy of cell surface growth in individual living cells. In latrunculin, which depolymerizes filamentous actin, cell surface growth was completely depolarized but still occurred, albeit at a reduced level. Thus, filamentous actin is necessary for polarized secretion but not for secretion per se. Consistent with this conclusion, latrunculin caused vesicles to accumulate at random positions throughout the cell. Cortical actin patches cluster at locations that correlate with sites of polarized secretion. However, we found that actin patch polarization is not necessary for polarized secretion because a mutant, bee1Δ(las17Δ), which completely lacks actin patch polarization, displayed polarized growth. In contrast, a mutant lacking actin cables, tpm1-2 tpm2Δ, had a severe defect in polarized growth. The yeast class V myosin Myo2p is hypothesized to mediate polarized secretion. A mutation in the motor domain of Myo2p, myo2-66, caused growth to be depolarized but with only a partial decrease in the level of overall growth. This effect is similar to that of latrunculin, suggesting that Myo2p interacts with filamentous actin. However, inhibition of Myo2p function by expression of its tail domain completely abolished growth.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=14879Documentos Relacionados
- Multiple Functions for Actin during Filamentous Growth of Saccharomyces cerevisiaeV⃞
- High-Voltage Electron Tomography of Spindle Pole Bodies and Early Mitotic Spindles in the Yeast Saccharomyces cerevisiaeV⃞
- The Rho-GEF Rom2p Localizes to Sites of Polarized Cell Growth and Participates in Cytoskeletal Functions in Saccharomyces cerevisiae
- The Glc7p-Interacting Protein Bud14p Attenuates Polarized Growth, Pheromone Response, and Filamentous Growth in Saccharomyces cerevisiae
- Cdc50p, a Conserved Endosomal Membrane Protein, Controls Polarized Growth in Saccharomyces cerevisiae