Abstract
A large GTPase dynamin, which is required for endocytic vesicle formation, regulates the actin cytoskeleton through its interaction with cortactin. Dynamin2 mutants impair the formation of actin comets, which are induced by Listeria monocytogenes or phosphatidylinositol-4-phosphate 5-kinase. However, the role of dynamin2 in the regulation of the actin comet is still unclear. Here we show that aberrant actin comets in dynamin2-depleted cells were rescued by disrupting of microtubule networks. Depletion of dynamin2, but not cortactin, significantly reduced the length and the speed of actin comets induced by Listeria. This implies that dynamin2 may regulate the actin comet in a cortactin-independent manner. As dynamin regulates microtubules, we investigated whether perturbation of microtubules would rescue actin comet formation in dynamin2-depleted cells. Treatment with taxol or colchicine created a microtubule-free space in the cytoplasm, and made no difference between control and dynamin2 siRNA cells. This suggests that the alteration of microtubules by dynamin2 depletion reduced the length and the speed of the actin comet.
Highlights
Dynamin GTPase plays an essential role in vesicle formation during endocytosis [1]
Both dynamin2 and cortactin localized in the actin comet tail, but cortactin localized in the actin cloud
Cortactin depletion had no significant effect on the length of the actin comet, as previously reported [21], but dynamin2 depletion significantly reduced both the comet tail length and speed of Listeria movement
Summary
Dynamin GTPase plays an essential role in vesicle formation during endocytosis [1]. Dynamin oligomerizes around the neck of the clathrin coat pit, and its GTPase activity is required for fission of the constricted membrane to produce endocytic vesicles. Dynamin is expressed in the brain, dynamin is ubiquitously expressed, and dynamin is expressed in neurons and testes [2,3]. All dynamin isoforms have five domains—the Nterminal GTPase domain, middle domain, pleckstrin homology domain, GTPase effector domain, and C-terminal proline rich domain (PRD). The GTPase domain plays a role in the hydrolysis of GTP. PRD connects with other SH3 domaincontaining proteins, such as amphiphysin, intersectin, and cortactin [4,5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
