Abstract
Global Ca2+ transients have been observed to precede nuclear envelope breakdown and the onset of anaphase in Swiss 3T3 fibroblasts in 8% (vol/vol) FBS. The occurrence of these Ca2+ transients was dependent on intracellular stores. These Ca2+ transients could be (a) abolished by serum removal without halting mitosis, and (b) eliminated by increasing intracellular Ca2+ buffering capacity through loading the cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) buffer, via the tetra(acetoxymethyl) ester, without hindering the transition into anaphase. Microinjection of sufficient concentrations of BAPTA buffer could block nuclear envelope breakdown. Pulses of Ca2+ generated by flash photolysis of intracellularly trapped nitr-5, a "caged" Ca2+, could precipitate precocious nuclear envelope breakdown in prophase cells. In metaphase cells, photochemically generated Ca2+ pulses could cause changes in the appearance of the chromosomes, but the length of time required for cells to make the transition from metaphase to anaphase remained essentially unchanged regardless of whether a Ca2+ pulse was photoreleased during metaphase. The results from these photorelease experiments were not dependent on the presence of serum in the medium. Discharging intracellular Ca2+ stores with ionomycin in the presence of 1.8 mM extracellular Ca2+ doubled the time for cells to pass from late metaphase into anaphase, whereas severe Ca2+ deprivation by treatment with ionomycin in EGTA-containing medium halted mitosis. Our results collectively indicate that Ca2+ is actively involved in nuclear envelope breakdown, but Ca2+ signals are likely unnecessary for the metaphase-anaphase transition in Swiss 3T3 fibroblasts. Additional studies of intracellular Ca2+ concentrations in mitotic REF52 and PtK1 cells revealed that Ca2+ transients are not observed at all mitotic stages in all cells. The absence of observable global Ca2+ transients, where calcium buffers can block and pulses of Ca2+ can advance mitotic stages, may imply that the relevant Ca2+ movements are too local to be detected.
Full Text
The Full Text of this article is available as a PDF (2.5 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Arslan P., Di Virgilio F., Beltrame M., Tsien R. Y., Pozzan T. Cytosolic Ca2+ homeostasis in Ehrlich and Yoshida carcinomas. A new, membrane-permeant chelator of heavy metals reveals that these ascites tumor cell lines have normal cytosolic free Ca2+. J Biol Chem. 1985 Mar 10;260(5):2719–2727. [PubMed] [Google Scholar]
- Dinsmore J. H., Sloboda R. D. Calcium and calmodulin-dependent phosphorylation of a 62 kd protein induces microtubule depolymerization in sea urchin mitotic apparatuses. Cell. 1988 Jun 3;53(5):769–780. doi: 10.1016/0092-8674(88)90094-3. [DOI] [PubMed] [Google Scholar]
- Foskett J. K., Gunter-Smith P. J., Melvin J. E., Turner R. J. Physiological localization of an agonist-sensitive pool of Ca2+ in parotid acinar cells. Proc Natl Acad Sci U S A. 1989 Jan;86(1):167–171. doi: 10.1073/pnas.86.1.167. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hepler P. K., Callaham D. A. Free calcium increases during anaphase in stamen hair cells of Tradescantia. J Cell Biol. 1987 Nov;105(5):2137–2143. doi: 10.1083/jcb.105.5.2137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hepler P. K., Wolniak S. M. Membranes in the mitotic apparatus: their structure and function. Int Rev Cytol. 1984;90:169–238. doi: 10.1016/s0074-7696(08)61490-4. [DOI] [PubMed] [Google Scholar]
- Izant J. G. The role of calcium ions during mitosis. Calcium participates in the anaphase trigger. Chromosoma. 1983;88(1):1–10. doi: 10.1007/BF00329497. [DOI] [PubMed] [Google Scholar]
- Kao J. P., Harootunian A. T., Tsien R. Y. Photochemically generated cytosolic calcium pulses and their detection by fluo-3. J Biol Chem. 1989 May 15;264(14):8179–8184. [PubMed] [Google Scholar]
- Keith C. H. Effect of microinjected calcium-calmodulin on mitosis in PtK2 cells. Cell Motil Cytoskeleton. 1987;7(1):1–9. doi: 10.1002/cm.970070102. [DOI] [PubMed] [Google Scholar]
- Keith C. H., Maxfield F. R., Shelanski M. L. Intracellular free calcium levels are reduced in mitotic Pt K2 epithelial cells. Proc Natl Acad Sci U S A. 1985 Feb;82(3):800–804. doi: 10.1073/pnas.82.3.800. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Keith C. H., Ratan R., Maxfield F. R., Bajer A., Shelanski M. L. Local cytoplasmic calcium gradients in living mitotic cells. 1985 Aug 29-Sep 4Nature. 316(6031):848–850. doi: 10.1038/316848a0. [DOI] [PubMed] [Google Scholar]
- Kiehart D. P. Studies on the in vivo sensitivity of spindle microtubules to calcium ions and evidence for a vesicular calcium-sequestering system. J Cell Biol. 1981 Mar;88(3):604–617. doi: 10.1083/jcb.88.3.604. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marty A., Neher E. Potassium channels in cultured bovine adrenal chromaffin cells. J Physiol. 1985 Oct;367:117–141. doi: 10.1113/jphysiol.1985.sp015817. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Minta A., Kao J. P., Tsien R. Y. Fluorescent indicators for cytosolic calcium based on rhodamine and fluorescein chromophores. J Biol Chem. 1989 May 15;264(14):8171–8178. [PubMed] [Google Scholar]
- Poenie M., Alderton J., Steinhardt R., Tsien R. Calcium rises abruptly and briefly throughout the cell at the onset of anaphase. Science. 1986 Aug 22;233(4766):886–889. doi: 10.1126/science.3755550. [DOI] [PubMed] [Google Scholar]
- Poenie M., Alderton J., Tsien R. Y., Steinhardt R. A. Changes of free calcium levels with stages of the cell division cycle. Nature. 1985 May 9;315(6015):147–149. doi: 10.1038/315147a0. [DOI] [PubMed] [Google Scholar]
- Ratan R. R., Maxfield F. R., Shelanski M. L. Long-lasting and rapid calcium changes during mitosis. J Cell Biol. 1988 Sep;107(3):993–999. doi: 10.1083/jcb.107.3.993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ratan R. R., Shelanski M. L., Maxfield F. R. Transition from metaphase to anaphase is accompanied by local changes in cytoplasmic free calcium in Pt K2 kidney epithelial cells. Proc Natl Acad Sci U S A. 1986 Jul;83(14):5136–5140. doi: 10.1073/pnas.83.14.5136. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Somlyo A. P., Bond M., Somlyo A. V. Calcium content of mitochondria and endoplasmic reticulum in liver frozen rapidly in vivo. Nature. 1985 Apr 18;314(6012):622–625. doi: 10.1038/314622a0. [DOI] [PubMed] [Google Scholar]
- Somlyo A. P. Cell physiology: cellular site of calcium regulation. Nature. 1984 Jun 7;309(5968):516–517. doi: 10.1038/309516b0. [DOI] [PubMed] [Google Scholar]
- Speksnijder J. E., Miller A. L., Weisenseel M. H., Chen T. H., Jaffe L. F. Calcium buffer injections block fucoid egg development by facilitating calcium diffusion. Proc Natl Acad Sci U S A. 1989 Sep;86(17):6607–6611. doi: 10.1073/pnas.86.17.6607. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steinhardt R. A., Alderton J. Intracellular free calcium rise triggers nuclear envelope breakdown in the sea urchin embryo. Nature. 1988 Mar 24;332(6162):364–366. doi: 10.1038/332364a0. [DOI] [PubMed] [Google Scholar]
- Tombes R. M., Borisy G. G. Intracellular free calcium and mitosis in mammalian cells: anaphase onset is calcium modulated, but is not triggered by a brief transient. J Cell Biol. 1989 Aug;109(2):627–636. doi: 10.1083/jcb.109.2.627. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsien R. Y., Pozzan T., Rink T. J. Calcium homeostasis in intact lymphocytes: cytoplasmic free calcium monitored with a new, intracellularly trapped fluorescent indicator. J Cell Biol. 1982 Aug;94(2):325–334. doi: 10.1083/jcb.94.2.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Twigg J., Patel R., Whitaker M. Translational control of InsP3-induced chromatin condensation during the early cell cycles of sea urchin embryos. Nature. 1988 Mar 24;332(6162):366–369. doi: 10.1038/332366a0. [DOI] [PubMed] [Google Scholar]
- Wolniak S. M., Hepler P. K., Jackson W. T. The coincident distribution of calcium-rich membranes and kinetochore fibers at metaphase in living endosperm cells of Haemanthus. Eur J Cell Biol. 1981 Aug;25(1):171–174. [PubMed] [Google Scholar]
- Ziegler M. L., Sisken J. E., Vedbrat S. The alteration of mitotic events by ionophore A23187 and carbonyl cyanide n-chlorophenylhydrazone. J Cell Sci. 1985 Apr;75:347–355. doi: 10.1242/jcs.75.1.347. [DOI] [PubMed] [Google Scholar]