Premium
Nuclear calcium and the regulation of the nuclear pore complex
Author(s) -
PerezTerzic Carmen,
Jaconi Marisa,
Clapham David E.
Publication year - 1997
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.950190908
Subject(s) - nuclear pore , nucleoporin , nucleoplasm , nuclear transport , nuclear lamina , biophysics , inner membrane , cytoplasm , nucleus , chemistry , cytosol , cell nucleus , nuclear protein , microbiology and biotechnology , biochemistry , membrane , biology , transcription factor , nucleolus , gene , enzyme
In eukaryotic cells the nucleus and its contents are separated from the cytoplasm by the nuclear envelope. Macromolecules, as well as smaller molecules and ions, can cross the nuclear envelope through the nuclear pore complex. Molecules greater than approx. 60 kDa and containing a nuclear localization signal are actively transported across the nuclear membranes, but there has been little evidence for regulatory mechanisms for smaller molecules and ions. Recently, diffusion across the nuclear envelope has been observed to be regulated by nuclear cisternal Ca 2+ concentrations. Following depletion of Ca 2+ from the nuclear store by inositol 1,4,5‐trisphosphate or Ca 2+ chelators, a fluorescent 10 kDa marker molecule was no longer able to enter the nucleus. Distinct conformational states of the nuclear pore complexes depended on the Ca 2+ filling state of the nuclear envelope, supporting the assumption that a switch in the conformation of the nuclear pore complex may control the transport of intermediate‐sized molecules across the nuclear envelope. Thus nuclear Ca 2+ stores may regulate the conformational state of the nuclear pore complex, and thereby passive diffusion of molecules between the cytosol and the nucleoplasm. The physiological significance of this finding is currently unknown.