Myosin-II negatively regulates minor process extension and the temporal development of neuronal polarity.
Myosin-II negatively regulates minor process extension and the temporal development of neuronal polarity.
复制标题
DOI：
10.1002/dneu.20704
复制
发表时间：
2009-04
影响因子：
3
通讯作者：
Gallo, G.
中科院分区：
文献类型：
--
作者：
Kollins, K. M.;Hu, J.;Bridgman, P. C.;Huang, Y. Q.;Gallo, G.
神经元极性发育的最早阶段是未分化的“小突起”(MPS)的延伸，随后分化为轴突和树突。我们利用前脑和海马神经元培养研究了肌球蛋白II运动蛋白在MP延伸中的作用。用肌球蛋白II ATPase抑制剂Blebbistatin慢性处理神经元可以增加MP的长度，这在肌球蛋白IIB基因敲除中也可以看到。通过活细胞成像，我们证明了肌球蛋白II的抑制会触发快速的小突起延伸到最大长度范围。肌球蛋白II的活性是由肌球蛋白轻链(MLCK)或RhoA-激酶(ROCK)介导的调节轻链(RMLC)的磷酸化决定的。药物抑制MLCK或ROCK可适度增加MP的长度，联合抑制这些激酶可导致MP长度的相加增加，与直接抑制肌球蛋白II的效果相似。选择性抑制ROCK上游的RhoA信号，结合细胞通透性C3转移酶，可增加MP的长度和数量。为了确定肌球蛋白II是否影响神经元极性的发育，在用直接或间接肌球蛋白II抑制剂处理的培养细胞中检测MP分化。值得注意的是，肌球蛋白II、MLCK或ROCK的抑制加速了神经元极性的发展。肌球蛋白II活性的增加，通过结构性激活的MLCK或RhoA，减少了MPS的长度和数量，从而延缓或消除了神经元的极性发育。综上所述，这些数据表明，肌球蛋白II负向调节MP的延长和轴突发生的发育时间进程。
The earliest stage in the development of neuronal polarity is characterized by extension of undifferentiated “minor processes” (MPs), which subsequently differentiate into the axon and dendrites. We investigated the role of the myosin II motor protein in MP extension using forebrain and hippocampal neuron cultures. Chronic treatment of neurons with the myosin II ATPase inhibitor blebbistatin increased MP length, which was also seen in myosin IIB knockouts. Through live-cell imaging we demonstrate that myosin II inhibition triggers rapid minor process extension to a maximum length range. Myosin II activity is determined by phosphorylation of its regulatory light chains (rMLC), mediated by myosin light chain kinase (MLCK) or RhoA-kinase (ROCK). Pharmacological inhibition of MLCK or ROCK increased MP length moderately, with combined inhibition of these kinases resulting in an additive increase in MP length similar to the effect of direct inhibition of myosin II. Selective inhibition of RhoA signaling upstream of ROCK, with cell-permeable C3 transferase, increased both the length and number of MPs. To determine whether myosin II affected development of neuronal polarity, MP differentiation was examined in cultures treated with direct or indirect myosin II inhibitors. Significantly, inhibition of myosin II, MLCK, or ROCK accelerated the development of neuronal polarity. Increased myosin II activity, through constitutively active MLCK or RhoA, decreased both the length and number of MPs and, consequently, delayed or abolished the development of neuronal polarity. Together, these data indicate that myosin II negatively regulates MP extension, and the developmental time course for axonogenesis.
登录
查看更多内容
影响因子：
4
作者：
de Anda, Froylan Calderon;Gaertner, Annette;Dotti, Carlos G.
通讯作者：
Dotti, Carlos G.
影响因子：
4.8
作者：
Gallagher, ED;Gutowski, S;Cobb, MH
通讯作者：
Cobb, MH
影响因子：
7.5
作者：
Bresnick, AR
通讯作者：
Bresnick, AR
影响因子：
4
作者：
Conti, Mary Anne;Adelstein, Robert S.
通讯作者：
Adelstein, Robert S.
影响因子：
16.8
作者：
Allingham, JS;Smith, R;Rayment, I
通讯作者：
Rayment, I