PT  - JOURNAL ARTICLE
AU  - Hiroyuki Kabayama
AU  - Makoto Takeuchi
AU  - Masahiko Taniguchi
AU  - Naoko Tokushige
AU  - Shunji Kozaki
AU  - Akihiro Mizutani
AU  - Takeshi Nakamura
AU  - Katsuhiko Mikoshiba
TI  - Syntaxin 1B Suppresses Macropinocytosis and Semaphorin 3A-Induced Growth Cone Collapse
AID  - 10.1523/JNEUROSCI.2718-10.2011
DP  - 2011 May 18
TA  - The Journal of Neuroscience
PG  - 7357--7364
VI  - 31
IP  - 20
4099  - http://www.jneurosci.org/content/31/20/7357.short
4100  - http://www.jneurosci.org/content/31/20/7357.full
SO  - J. Neurosci.2011 May 18; 31
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.