New aspects of nuclear calcium signalling.
Nuclear calcium signalling has been a controversial battlefield for many years and the question of how permeable the nuclear pore complexes (NPCs) are to Ca2+ has been the subject of a particularly hot dispute. Recent data from isolated nuclei suggest that the NPCs are open even after depletion of the Ca2+ store in the nuclear envelope. Other research has suggested that a new Ca2+ -releasing messenger, nicotinic acid adenine dinucleotide phosphate (NAADP), can liberate Ca2+ only from acidic organelles, probably lysosomes, rather than from the traditional Ca2+ store in the endoplasmic reticulum (ER). Recent work indicates that NAADP can release Ca2+ from the nuclear envelope (NE), which has a thapsigargin-sensitive, ER-type Ca2+ store. NAADP acts in a manner similar to inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] or cyclic ADP-ribose (cADPR): all three messengers are equally able to reduce the Ca2+ concentration inside the NE and this is associated with a transient rise in the nucleoplasmic Ca2+ concentration. The NE contains ryanodine receptors (RyRs) and Ins(1,4,5)P3 receptors [Ins(1,4,5)P3Rs], and these can be activated separately and independently: the RyRs by either NAADP or cADPR, and the Ins(1,4,5)P3Rs by Ins(1,4,5)P3.
Gerasimenko
Oleg
O
MRC Secretory Control Research Group, The Physiological Laboratory, University of Liverpool, Crown Street, L69 3BX, UK. o.v.gerasimenko@liverpool.ac.uk
Gerasimenko
Julia
J
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D036563:Cyclic ADP-Ribose / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D008954:Models, Biological; D009249:NADP / Q000031:analogs & derivatives* / Q000494:pharmacology; D010179:Pancreas / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D015398:Signal Transduction; D019284:Thapsigargin / Q000494:pharmacology
D019837:Ryanodine Receptor Calcium Release Channel; D036563:Cyclic ADP-Ribose; D009249:NADP; C024376:NAADP; D019284:Thapsigargin; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium