Roelink H, Porter J A, Chiang C, Tanabe Y, Chang D T, Beachy P A, Jessell T M
Howard Hughes Medical Institute, Columbia University, New York, New York 10032, USA.
Cell. 1995 May 5;81(3):445-55. doi: 10.1016/0092-8674(95)90397-6.
The differentiation of floor plate cells and motor neurons can be induced by Sonic hedgehog (SHH), a secreted signaling protein that undergoes autoproteolytic cleavage to generate amino- and carboxy-terminal products. We have found that both floor plate cells and motor neurons are induced by the amino-terminal cleavage product of SHH (SHH-N). The threshold concentration of SHH-N required for motor neuron induction is about 5-fold lower than that required for floor plate induction. Higher concentrations of SHH-N can induce floor plate cells at the expense of motor neuron differentiation. Our results suggest that the induction of floor plate cells and motor neurons by the notochord in vivo is mediated by exposure of neural plate cells to different concentrations of the amino-terminal product of SHH autoproteolytic cleavage.
底板细胞和运动神经元的分化可由音猬因子（SHH）诱导，SHH是一种分泌型信号蛋白，会经历自蛋白水解切割以产生氨基末端和羧基末端产物。我们发现，底板细胞和运动神经元均由SHH的氨基末端切割产物（SHH-N）诱导。诱导运动神经元所需的SHH-N阈值浓度比诱导底板所需的浓度低约5倍。更高浓度的SHH-N可诱导底板细胞，但会以运动神经元分化为代价。我们的结果表明，脊索在体内对底板细胞和运动神经元的诱导是通过神经板细胞暴露于不同浓度的SHH自蛋白水解切割的氨基末端产物来介导的。
