Ubiquitin-mediated processes in erythroid cell maturation.
Ubiquitin-mediated processes in erythroid cell maturation.
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DOI：
10.1007/978-1-4684-5985-2_18
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发表时间：
1991
影响因子：
--
通讯作者：
A. Haas
中科院分区：
文献类型：
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作者：
A. Haas
红细胞成熟过程中，红母细胞的终末分化需要显著的细胞重塑。在鸟类细胞中，这部分是通过细胞核转录的显著衰减来完成的，而在哺乳动物细胞中，这部分是通过细胞核的物理挤压来完成的。因此，除了维持成熟红细胞所需的那些蛋白质外，缺乏替代所有蛋白质的能力，细胞成分的正常补体随后被一个高度活跃的降解机制修饰，以产生对这种蛋白质水解稳定的蛋白质亚群。在此期间，许多代谢途径被关键酶的选择性周转所分流。红细胞成熟所必需的增强降解被认为涉及相同的ATP，泛素依赖的多酶途径，负责所有真核生物的胞质蛋白周转。使红母细胞增强降解和指导关键酶的选择性降解所需的机制为有核细胞中观察到的较不急性的调节提供了一个易于处理的模型。红细胞中ATP、泛素依赖通路的表征，以及最近在其他细胞和组织中观察到的各种实验操作导致的增强降解，提供了对该系统在终末分化过程中所表现出的动力学的一些理解。
The terminal differentiation of erythroblasts during erythrocyte maturation entails significant cellular remodeling. In avian cells this is accomplished in part by marked attenuation of nuclear transcription and in mammalian cells by the physical extrusion of the nucleus. Thus lacking the ability to replace all but those proteins required for maintenance of the mature erythrocyte, the normal complement of cellular constituents is subsequently modified by a highly active degradative mechanism(s) to yield a sub-population of proteins stable to such proteolysis. During this time many metabolic pathways are shunted by selective turnover of key enzymes. The enhanced degradation essential to erythroid cell maturation is assumed to involve the same ATP, ubiquitin-dependent multi-enzyme pathway responsible for cytosolic protein turnover within all eukaryotes. The mechanism(s) required to commit erythroblasts to enhanced degradation and to direct the resulting selective degradation of key enzymes provides a tractable model for the less acute regulation observed within nucleated cells. Characterization of the ATP, ubiquitin-dependent pathway in erythroid cells and recent observations in other cells and tissues subject to enhanced degradation in response to various experimental manipulations provides some understanding of the dynamics exhibited by this system during terminal differentiation.