Journal Article

The nucleus is insulated from large cytosolic calcium ion changes

Caddy, Keith W. T., Bolsover, Stephen R., Al-Mohanna, Futwan A.

1994

Overview

EXTRACELLULAR events regulate functions in the cell nucleus by means of calcium ions acting through effector enzymes 1–5 . Recently, the traditional view of the nuclear pore as freely permeable to small ions 6,7 has been questioned as a result of reports that nuclear calcium can be regulated independently of cytosolic calcium 8–12 . We have used confocal microscopy of fluorescent Ca 2+ indicators to investigate the Ca 2+ dynamics between cytosol and nucleus in neurons. We find that a previously reported amplification of Ca 2+ changes in the nucleus 13–16 is a measurement artefact. Small changes of cytosolic Ca 2+ cause equally rapid changes in nuclear Ca 2+ , consistent with the free diffusion of Ca 2+ through nuclear pores. In contrast, large cytosolic Ca 2+ increases (above 300 nM) are attenuated in the nucleus. Our results show the nuclear envelope shapes but does not block the passage of Ca 2+ signals from cytosol to nucleus.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Animals / Biological and medical sciences / Calcium / Calcium - metabolism / Cell Nucleus - physiology / Cytosol - metabolism / Diffusion / Fluorescence / Fundamental and applied biological sciences. Psychology / Humanities and Social Sciences / Ions / Isolated neuron and nerve. Neuroglia / letter / Mice / Microscopy / Microscopy, Phase-Contrast / multidisciplinary / Neuroblastoma / Neurons - metabolism / Nuclear Envelope - physiology / Science / Science (multidisciplinary) / Tumor Cells, Cultured / Vertebrates: nervous system and sense organs