RT Journal Article
SR Electronic
T1 Syntaxin 1B Suppresses Macropinocytosis and Semaphorin 3A-Induced Growth Cone Collapse
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 7357
OP 7364
DO 10.1523/JNEUROSCI.2718-10.2011
VO 31
IS 20
A1 Hiroyuki Kabayama
A1 Makoto Takeuchi
A1 Masahiko Taniguchi
A1 Naoko Tokushige
A1 Shunji Kozaki
A1 Akihiro Mizutani
A1 Takeshi Nakamura
A1 Katsuhiko Mikoshiba
YR 2011
UL http://www.jneurosci.org/content/31/20/7357.abstract
AB Growth cone collapse is a crucial process for repulsive axon guidance and is accompanied by a reduction in growth cone surface area. This process of reduction may be regulated by endocytosis; however, its molecular mechanism is unclear. Macropinocytosis is a clathrin-independent form of endocytosis in which large areas of plasma membrane can be engulfed. We have reported previously that macropinocytosis is induced in growth cones of chick dorsal root ganglion neurons by semaphorin 3A (Sema3A), a repulsive axon guidance cue, and that Sema3A-induced reduction in growth cone surface area and macropinocytic vacuole area were correlated, suggesting a positive role for macropinocytosis in Sema3A-induced growth cone collapse. In the present study, we found that syntaxin 1B (Syx1B), a membrane trafficking protein, is a negative regulator of macropinocytosis, and its expression is downregulated by Sema3A signaling. Macropinocytosis inhibitor ethylisopropylamiloride or Syx1B overexpression suppressed Sema3A-induced macropinocytosis and growth cone collapse. These results indicate that Syx1B couples macropinocytosis-mediated massive internalization of the plasma membrane to Sema3A-induced growth cone collapse.