Neuronal Ca2+ signaling via caldendrin and calneurons.
The calcium sensor protein caldendrin is abundantly expressed in neurons and is thought to play an important role in different aspects of synapto-dendritic Ca2+ signaling. Caldendrin is highly abundant in the postsynaptic density of a subset of excitatory synapses in brain and its distinct localization raises several decisive questions about its function. Previous work suggests that caldendrin is tightly associated with Ca2+ - and Ca2+ release channels and might be involved in different aspects of the organization of the postsynaptic scaffold as well as with synapse-to-nucleus communication. In this report we introduce two new EF-hand calcium sensor proteins termed calneurons that apart from calmodulin represent the closest homologues of caldendrin in brain. Calneurons have a different EF-hand organization than other calcium sensor proteins, are prominently expressed in neurons and will presumably bind Ca2+ with higher affinity than caldendrin. Despite some significant structural differences it is conceivable that they are involved in similar Ca2+ regulated processes like caldendrin and neuronal calcium sensor proteins.
Mikhaylova
Marina
M
AG Molecular Mechanisms of Plasticity, Department of Neurochemistry/Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestrasse 6, 39118 Magdeburg, Germany.
Sharma
Yogendra
Y
Reissner
Carsten
C
Nagel
Falko
F
Aravind
Penmatsa
P
Rajini
Bheemreddy
B
Smalla
Karl-Heinz
KH
Gundelfinger
Eckart D
ED
Kreutz
Michael R
MR
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D020013:Calcium Signaling; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D011487:Protein Conformation; D051381:Rats
D002135:Calcium-Binding Proteins; C516555:calneuron I, rat; C516556:calneuron II, rat; C085577:Ca2+-binding protein-1