Toxoplasma gondii myosins B/C: one gene, two tails, two localizations, anda role in parasite division

Citation
F. Delbac et al., Toxoplasma gondii myosins B/C: one gene, two tails, two localizations, anda role in parasite division, J CELL BIOL, 155(4), 2001, pp. 613-623
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
155
Issue
4
Year of publication
2001
Pages
613 - 623
Database
ISI
SICI code
0021-9525(20011112)155:4<613:TGMBOG>2.0.ZU;2-L
Abstract
In apicomplexan parasites, actin-disrupting drugs and the inhibitor of myos in heavy chain ATPase, 2,3-butanedione monoxime, have been shown to interfe re with host cell invasion by inhibiting parasite gliding motility. We repo rt here that the actomyosin system of Toxoplasma gondii also contributes to the process of cell division by ensuring accurate budding of daughter cell s. T gondii myosins B and C are encoded by alternatively spliced mRNAs and differ only in their COOH-terminal tails. MyoB and MyoC showed distinct sub cellular localizations and dissimilar solubilities, which were conferred by their tails. MyoC is the first marker selectively concentrated at the ante rior and posterior polar rings of the inner membrane complex, structures th at play a key role in cell shape integrity during daughter cell biogenesis. When transiently expressed, MyoB, MyoC, as well as the common motor domain lacking the tail did not distribute evenly between daughter cells, suggest ing some impairment in proper segregation. Stable overexpression of MyoB ca used a significant defect in parasite cell division, leading to the formati on of extensive residual bodies, a substantial delay in replication, and lo ss of acute virulence in mice. Altogether, these observations suggest that MyoB/C products play a role in proper daughter cell budding and separation.