BIPHASIC PATTERN OF GELSOLIN EXPRESSION AND VARIATIONS IN GELSOLIN ACTIN INTERACTIONS DURING MYOGENESIS
BIPHASIC PATTERN OF GELSOLIN EXPRESSION AND VARIATIONS IN GELSOLIN ACTIN INTERACTIONS DURING MYOGENESIS
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DOI：
10.1006/excr.1995.1243
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发表时间：
1995-08-01
影响因子：
3.7
通讯作者：
HINSSEN, H
中科院分区：
文献类型：
--
作者：
SCHOLZ, A;HINSSEN, H
在体外肌生成过程中，肌生成细胞中凝溶胶蛋白的量增加了约3倍，从每毫克总蛋白约200 ng增加到最大750 ng。凝溶胶蛋白从成肌细胞状态稳定增加到含有丰富横纹肌原纤维的终末分化肌管。同时，总肌动蛋白的量仅变化约30%，凝溶胶蛋白：肌动蛋白的摩尔比从1：500增加到约1：150。在禽类和哺乳动物的肌细胞培养物中均观察到凝溶胶蛋白表达的这种调节。一旦在肌培养中达到终末分化状态，凝溶胶蛋白的量再次下降。另一方面，凝溶胶蛋白在出生后小鼠肌肉中连续减少，在出生后第1天和第12天之间减少了约5倍。当用Triton X-100提取来自不同分化阶段的肌源性细胞时，大部分凝溶胶蛋白是可溶的，而小部分与细胞骨架紧密相关。不溶性凝溶胶蛋白的实际溶解度取决于提取过程中的Ca 2+浓度和分化程度。在[Ca ~（2+）] >10（-5）M时，在所有分化阶段，约三分之一的凝溶胶蛋白与细胞骨架结合，在存在EGTA的情况下，Triton提取后，不溶性凝溶胶蛋白的量在分化期间从3%增加到17%。可溶性肌动蛋白的量从40%下降到25%，在同一时期，独立的Ca 2+浓度。我们计算出与细胞骨架或肌原纤维系统相关的凝溶胶蛋白的量在分化的肌管中比在早期肌管中高约20倍，表明凝溶胶蛋白在肌原纤维组装中的功能作用。(C)出版社：Academic Press
During myogenesis in vitro, the amount of gelsolin in myogenic cells increased by a factor of similar to 3 from about 200 ng to a maximum of 750 ng per milligram of total protein. Gelsolin increased steadily from the myoblast state to terminally differentiated myotubes containing abundant cross-striated myofibrils. At the same time, the amount of total actin varied by only about 30%, the molar ratio of gelsolin:actin increased from 1:500 to approximately 1:150. This modulation of gelsolin expression was observed both in avian and mammalian myocultures. Once the state of terminal differentiation in myocultures was attained, the amount of gelsolin decreased again. On the other hand, gelsolin decreased continuously in the postnatal mouse muscle by a factor of similar to 5 between Day 1 and Day 12 after birth, When myogenic cells from various stages of differentiation were extracted with Triton X-100, the majority of gelsolin was soluble, whereas a minor fraction was tightly associated with the cytoskeleton. The actual amount-of insoluble gelsolin depended on both the Ca2+ concentration during extraction and the degree of differentiation. Whereas at [Ca2+] >10(-5) M about one-third of the total gelsolin was associated with the cytoskeleton at all stages of differentiation, the amount of insoluble gelsolin after Triton extraction in the presence of EGTA increased from 3 to 17% during differentiation. The amount of soluble actin decreased from 40 to 25% during the same period, independent of the Ca2+ concentration. We calculated that the amount of gelsolin associated with the cytoskeletal or myofibrillar system is approximately 20-fold higher in differentiated myotubes than in early myotubes, indicating a functional role of gelsolin for myofibrillar assembly. (C) 1995 Academic Press, Inc.