REGULATION OF NUCLEAR TRANSPORT IN PROLIFERATING AND QUIESCENT CELLS
REGULATION OF NUCLEAR TRANSPORT IN PROLIFERATING AND QUIESCENT CELLS
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DOI：
10.1006/excr.1993.1073
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发表时间：
1993-03-01
影响因子：
3.7
通讯作者：
AKIN, D
中科院分区：
文献类型：
--
作者：
FELDHERR, CM;AKIN, D
在此之前，我们比较了信号介导的核运输在增殖和静止的BALB/c 3 T3细胞，并发现核摄取的相对速率和功能的大小的运输通道显着更大的增殖细胞。在这项研究中，这些渗透性差异的可能原因进行了调查。为了确定静止细胞中转运能力的降低是否是由于可溶性细胞质因子的可用性降低（即，ATP或核定位序列的受体），或孔本身性质的变化，将增殖和静止细胞融合，并在50-60分钟后在异核体中测定核质蛋白包被的金（NP-金）颗粒的核输入。核摄取的显着差异保持融合后，即使两个核共享一个共同的细胞质，一致的观点，即渗透性调节的水平孔。细胞形状也影响信号介导的核输入。这是证明了通过研究运输圆形和扁平的细胞连接到不同大小的钯域沉积在非粘性基板上。基于对大（直径110-270 μ m）和小（直径50-80 μ m）包被的金颗粒的核摄取率的分析，确定扁平细胞中孔的功能尺寸显著更大。还分析了生长因子对血清耗竭后核转运能力恢复的影响。通过用生理浓度的EGF、IGF-1或PDGF处理细胞实现部分恢复;然而，完全恢复需要EGF和IGF-1。
Previously, we compared signal-mediated nuclear transport in proliferating and quiescent BALB/c 3T3 cells and found that both the relative rate of nuclear uptake and the functional size of the transport channels were significantly greater in proliferating cells. In this study, the possible causes of these permeability differences were investigated. To determine if the decrease in transport capacity in quiescent cells was due to a reduction in the availability of soluble cytoplasmic factors (i.e., ATP or receptors for nuclear location sequences), or changes in the properties of the pores themselves, proliferating and quiescent cells were fused, and nuclear import of nucleoplasmin-coated gold (NP-gold) particles was assayed in the heterokaryons 50-60 min later. Significant differences in nuclear uptake were maintained following fusion, even though the two nuclei shared a common cytoplasm, consistent with the view that permeability is regulated at the level of the pores. Cell shape also influenced signal-mediated nuclear import. This was demonstrated by studying transport in rounded and flattened cells attached to different-size palladium domains that were deposited on a nonadhesive substrate. Based on analysis of the nuclear uptake rates of large (110-270 Å in diameter) and small (50-80 Å in diameter) coated gold particles, it was determined that the functional size of the pores was significantly greater in flattened cells. The effect of growth factors on recovery of nuclear transport capacity following serum depletion was also analyzed. Partial recovery was achieved by treating cells with physiological concentrations of EGF, IGF-1, or PDGF; however, complete recovery required both EGF and IGF-1.