Secretory vesicle transport velocity in living cells depends on the myosin-V lever arm length
2002; Rockefeller University Press; Volume: 156; Issue: 1 Linguagem: Inglês
10.1083/jcb.200110086
ISSN1540-8140
AutoresDaniel Schott, Ruth Collins, Anthony Bretscher,
Tópico(s)Microtubule and mitosis dynamics
ResumoMyosins are molecular motors that exert force against actin filaments. One widely conserved myosin class, the myosin-Vs, recruits organelles to polarized sites in animal and fungal cells. However, it has been unclear whether myosin-Vs actively transport organelles, and whether the recently challenged lever arm model developed for muscle myosin applies to myosin-Vs. Here we demonstrate in living, intact yeast that secretory vesicles move rapidly toward their site of exocytosis. The maximal speed varies linearly over a wide range of lever arm lengths genetically engineered into the myosin-V heavy chain encoded by the MYO2 gene. Thus, secretory vesicle polarization is achieved through active transport by a myosin-V, and the motor mechanism is consistent with the lever arm model.
Referência(s)