Structural complexity and functional diversity of endoplasmic reticulum Ca(2+) stores.
Considerable evidence, including recent direct observations, suggest that endoplasmic reticulum (ER) Ca(2+) stores in neurons, glia, and other cell types, consists of spatially-distinct compartments that can be individually loaded and unloaded. In addition, sub-plasmalemmal ('junctional') components of the ER (jER) are functionally coupled to the overlying plasmalemmal (PL) microdomains in PL-jER units named 'PLasmERosomes'. The PL microdomains and the jER contain clusters of specific transport proteins that regulate Na(+) and Ca(2+) concentrations in the tiny cytosolic space between the PL and jER. This organization helps the ER to produce the many types of complex local and global Ca(2+) signals that are responsible for the simultaneous control of numerous neuronal and glial functions.
Blaustein
M P
MP
Department of Physiology, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD 21201, USA. mblauste@umaryland.edu
Golovina
V A
VA
D000818:Animals; D002118:Calcium / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000502:physiology*; D006801:Humans; D009457:Neuroglia / Q000502:physiology; D009474:Neurons / Q000502:physiology
D002118:Calcium