Long-lasting and rapid calcium changes during mitosis.
Long-lasting and rapid calcium changes during mitosis.
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DOI：
10.1083/jcb.107.3.993
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发表时间：
1988-09
影响因子：
7.8
通讯作者：
Shelanski, M L
中科院分区：
文献类型：
--
作者：
Ratan, R R;Maxfield, F R;Shelanski, M L
要更全面地了解钙在细胞分裂中的作用，需要了解与特定有丝分裂事件相关的胞质游离钙（[Ca 2 +]i）变化的时间、幅度和持续时间。为了确定[Ca 2 +]i变化与细胞和染色体运动的时间关系，我们使用Fura-2和显微分光光度法每6-7秒测量一次单分裂Pt K2细胞中的[Ca 2 +]i，将每个钙测量与亮场观察相结合。在可分辨的染色体分离前12 min内，90%的中期分裂相细胞至少出现一次[Ca ~（2+）]i升高，72%的中期分裂相细胞在5 min内出现最后一次[Ca ~（2+）]i升高，在染色体分离前3 min出现一次[Ca ~（2+）] i升高高峰。中期瞬变的平均[Ca 2 +]i为148 +/- 31 nM（35个细胞中有61个瞬变），平均持续时间为21 +/- 14 s。这些增加的时间使得这些[Ca 2 +]i的瞬时增加不太可能直接触发后期的开始。然而，有可能在中期晚期钙离子的短暂升高是更复杂的后期进展的一部分。除了这些短暂的变化，[Ca 2 +]i的逐渐增加，观察后期开始。在胞质分裂开始的2分钟内，82%的细胞显示[Ca 2 +]i瞬时增加至171 +/- 48 nM（32个细胞中有53个瞬时）。这些变化与卵裂的密切时间相关性与钙在此事件中的更直接作用一致，可能是通过激活收缩系统。为了评估这些变化对有丝分裂周期的特异性，我们检测了间期细胞中钙的变化。三分之二的间期细胞未显示钙的瞬时增加，平均[Ca 2 +]i为100 +/-18 nM（n = 12）.然而，三分之一的人表现出[Ca 2 +]i的急剧和反复的瞬时增加。这些瞬变的平均峰值[Ca 2 +]i为389 +/- 70 nM，平均持续时间为77 s。有丝分裂或分裂间期活动完成的钙的任何这些短暂变化的必要性仍在调查中。
A more complete understanding of calcium's role in cell division requires knowledge of the timing, magnitude, and duration of changes in cytoplasmic-free calcium, [Ca2+]i, associated with specific mitotic events. To define the temporal relationship of changes in [Ca2+]i to cellular and chromosomal movements, we have measured [Ca2+]i every 6-7 s in single-dividing Pt K2 cells using fura-2 and microspectrophotometry, coupling each calcium measurement with a bright- field observation. In the 12 min before discernable chromosome some separation, 90% of metaphase cells show at least one transient of increased [Ca2+]i, 72% show their last transient within 5 min, and a peak of activity is seen at 3 min before chromosome separation. The mean [Ca2+]i of the metaphase transients is 148 +/- 31 nM (61 transients in 35 cells) with an average duration of 21 +/- 14 s. The timing of these increases makes it unlikely that these transient increases in [Ca2+]i are acting directly to trigger the start of anaphase. However, it is possible that a transient rise in calcium during late metaphase is part of a more complex progression to anaphase. In addition to these transient changes, a gradual increase in [Ca2+]i was observed starting in late anaphase. Within the 2 min surrounding cytokinesis onset, 82% of cells show a transient increase in [Ca2+]i to 171 +/- 48 nM (53 transients in 32 cells). The close temporal correlation of these changes with cleavage is consistent with a more direct role for calcium in this event, possibly by activating the contractile system. To assess the specificity of these changes to the mitotic cycle, we examined calcium changes in interphase cells. Two- thirds of interphase cells show no transient increases in calcium with a mean [Ca2+]i of 100 +/- 18 nM (n = 12). However, one-third demonstrate dramatic and repeated transient increases in [Ca2+]i. The mean peak [Ca2+]i of these transients is 389 +/- 70 nM with an average duration of 77 s. The necessity of any of these transient changes in calcium for the completion of mitotic or interphase activities remains under investigation.