Directed motility of phagosomes in Tetrahymena thermophila requires actin and Myo1p, a novel unconventional myosin.
Cell Motil Cytoskeleton
; 61(1): 49-60, 2005 May.
Article
em En
| MEDLINE
| ID: mdl-15810016
ABSTRACT
The phagosome cycle was investigated in Tetrahymena thermophila, which had internalized fluorescent latex beads. Confocal microscopy of cells from a GFP-actin strain revealed actin filaments that extended 3-5 mum from the periphery of fluorescent phagosomes. In GFP-actin cells and in wild-type cells, motility of fluorescent phagosomes was directed from the oral cavity to the posterior end of the cell. Although 60% of fluorescent phagosomes in the MYO1-knockout strain were motile, movement of phagosomes was not directed toward the posterior end of the cell and was random. Forty percent of fluorescent phagosomes in knockout cells were non-motile in contrast to only 20% non-motile phagosomes in wild-type cells. The increased incidence of non-motile phagosomes in the knockout strain could reflect absence of Myo1p as a motor. Another myosin or other molecular motors could power random movement of phagosomes in the MYO1-knockout strain. In latrunculin-treated GFP-actin cells, movement of fluorescent phagosomes was random. Average velocity of random movement of fluorescent phagosomes in the knockout strain and in latrunculin-treated cells was statistically the same as the average velocity (2.0 +/- 1.9 microm/min) of phagosomes in GFP-actin cells. These findings are an indication that dynamic actin and Myo1p are required for directed motility of phagosomes.
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Base de dados:
MEDLINE
Assunto principal:
Fagossomos
/
Proteínas de Protozoários
/
Actinas
/
Tetrahymena thermophila
/
Cadeias Pesadas de Miosina
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article