Abstract
Dynamin GTPase, a key molecule in endocytosis, mechanically severs the invaginated membrane upon GTP hydrolysis. Dynamin functions also in regulating actin cytoskeleton, but the mechanisms are yet to be defined. Here we show that dynamin 1, a neuronal isoform of dynamin, and cortactin form ring complexes, which twine around F-actin bundles and stabilize them. By negative-staining EM, dynamin 1 cortactin complexes appeared as "open" or "closed" rings depending on guanine nucleotide conditions. By pyrene actin assembly assay, dynamin 1 stimulated actin assembly in mouse brain cytosol. In vitro incubation of F-actin with both dynamin 1 and cortactin led to the formation of long and thick actin bundles, on which dynamin 1 and cortactin were periodically colocalized in puncta. A depolymerization assay revealed that dynamin 1 and cortactin increased the stability of actin bundles, most prominently in the presence of GTP. In rat cortical neurons and human neuroblastoma cell line, SH-SY5Y, both dynamin 1 and cortactin localized on actin filaments and the bundles at growth cone filopodia as revealed by immunoelectron microscopy. In SH-SY5Y cell, acute inhibition of dynamin 1 by application of dynamin inhibitor led to growth cone collapse. Cortactin knockdown also reduced growth cone filopodia. Together, our results strongly suggest that dynamin 1 and cortactin ring complex mechanically stabilizes F-actin bundles in growth cone filopodia. Thus, the GTPase-dependent mechanochemical enzyme property of dynamin is commonly used both in endocytosis and regulation of F-actin bundles by a dynamin 1 cortactin complex.
| Original language | English |
|---|---|
| Pages (from-to) | 4514-4526 |
| Number of pages | 13 |
| Journal | Journal of Neuroscience |
| Volume | 33 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Mar 6 2013 |
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Stabilization of actin bundles by a Dynamin 1/cortactin ring complex is necessary for growth cone filopodia. / Yamada, Hiroshi; Abe, Tadashi; Satoh, Ayano; Okazaki, Nana; Tago, Shota; Kobayashi, Kinue; Yoshida, Yumi; Oda, Yoshiya; Watanabe, Masami; Tomizawa, Kazuhito; Matsui, Hideki; Takei, Kohji.
In: Journal of Neuroscience, Vol. 33, No. 10, 06.03.2013, p. 4514-4526.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Stabilization of actin bundles by a Dynamin 1/cortactin ring complex is necessary for growth cone filopodia
AU - Yamada, Hiroshi
AU - Abe, Tadashi
AU - Satoh, Ayano
AU - Okazaki, Nana
AU - Tago, Shota
AU - Kobayashi, Kinue
AU - Yoshida, Yumi
AU - Oda, Yoshiya
AU - Watanabe, Masami
AU - Tomizawa, Kazuhito
AU - Matsui, Hideki
AU - Takei, Kohji
PY - 2013/3/6
Y1 - 2013/3/6
N2 - Dynamin GTPase, a key molecule in endocytosis, mechanically severs the invaginated membrane upon GTP hydrolysis. Dynamin functions also in regulating actin cytoskeleton, but the mechanisms are yet to be defined. Here we show that dynamin 1, a neuronal isoform of dynamin, and cortactin form ring complexes, which twine around F-actin bundles and stabilize them. By negative-staining EM, dynamin 1 cortactin complexes appeared as "open" or "closed" rings depending on guanine nucleotide conditions. By pyrene actin assembly assay, dynamin 1 stimulated actin assembly in mouse brain cytosol. In vitro incubation of F-actin with both dynamin 1 and cortactin led to the formation of long and thick actin bundles, on which dynamin 1 and cortactin were periodically colocalized in puncta. A depolymerization assay revealed that dynamin 1 and cortactin increased the stability of actin bundles, most prominently in the presence of GTP. In rat cortical neurons and human neuroblastoma cell line, SH-SY5Y, both dynamin 1 and cortactin localized on actin filaments and the bundles at growth cone filopodia as revealed by immunoelectron microscopy. In SH-SY5Y cell, acute inhibition of dynamin 1 by application of dynamin inhibitor led to growth cone collapse. Cortactin knockdown also reduced growth cone filopodia. Together, our results strongly suggest that dynamin 1 and cortactin ring complex mechanically stabilizes F-actin bundles in growth cone filopodia. Thus, the GTPase-dependent mechanochemical enzyme property of dynamin is commonly used both in endocytosis and regulation of F-actin bundles by a dynamin 1 cortactin complex.
AB - Dynamin GTPase, a key molecule in endocytosis, mechanically severs the invaginated membrane upon GTP hydrolysis. Dynamin functions also in regulating actin cytoskeleton, but the mechanisms are yet to be defined. Here we show that dynamin 1, a neuronal isoform of dynamin, and cortactin form ring complexes, which twine around F-actin bundles and stabilize them. By negative-staining EM, dynamin 1 cortactin complexes appeared as "open" or "closed" rings depending on guanine nucleotide conditions. By pyrene actin assembly assay, dynamin 1 stimulated actin assembly in mouse brain cytosol. In vitro incubation of F-actin with both dynamin 1 and cortactin led to the formation of long and thick actin bundles, on which dynamin 1 and cortactin were periodically colocalized in puncta. A depolymerization assay revealed that dynamin 1 and cortactin increased the stability of actin bundles, most prominently in the presence of GTP. In rat cortical neurons and human neuroblastoma cell line, SH-SY5Y, both dynamin 1 and cortactin localized on actin filaments and the bundles at growth cone filopodia as revealed by immunoelectron microscopy. In SH-SY5Y cell, acute inhibition of dynamin 1 by application of dynamin inhibitor led to growth cone collapse. Cortactin knockdown also reduced growth cone filopodia. Together, our results strongly suggest that dynamin 1 and cortactin ring complex mechanically stabilizes F-actin bundles in growth cone filopodia. Thus, the GTPase-dependent mechanochemical enzyme property of dynamin is commonly used both in endocytosis and regulation of F-actin bundles by a dynamin 1 cortactin complex.
UR - http://www.scopus.com/inward/record.url?scp=84874632542&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84874632542&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.2762-12.2013
DO - 10.1523/JNEUROSCI.2762-12.2013
M3 - Article
C2 - 23467367
AN - SCOPUS:84874632542
VL - 33
SP - 4514
EP - 4526
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 10
ER -