Nuclear calcium signalling.
The topic of nuclear Ca2+ signalling is beset by discrepant observations of substantial nuclear/cytoplasmic gradients. The reasons why some labs have recorded such gradients, whilst other workers see equilibration of Ca2+(cyt) and Ca2+(nuc) using the same cells and techniques, is unexplained. Furthermore, how such gradients could arise across the NE that possesses many highly-conductive NPCs is a mystery. Although nuclei may have the capacity to be autonomous signalling entities, with functional Ca2+ release channels and an inositide cycle, the balance of evidence suggests that Ca2+ release on the inner NE does not occur during physiological stimulation. Our work suggests that elementary Ca2+ release events originating in the cytoplasm can give rise to Ca2+ signals without causing elevation of the bulk cytoplasm. Clearly, the many Ca2+ signalling mechanisms that may impinge on Ca2+(nuc) will remain a topic of controversy and debate for some time.
Bootman
M D
MD
Laboratory of Molecular Signalling, The Babraham Institute, Cambridge, United Kingdom. martin.bootman@bbsrc.ac.uk
Thomas
D
D
Tovey
S C
SC
Berridge
M J
MJ
Lipp
P
P
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002467:Cell Nucleus / Q000502:physiology*; D006801:Humans; D015398:Signal Transduction
D002118:Calcium