Isoform-specific distribution of the plasma membrane Ca2+ ATPase in the rat brain.
Regulation of cytoplasmic calcium is crucial both for proper neuronal function and cell survival. The concentration of Ca2+ in cytoplasm of a neuron at rest is 10,000 times lower than in the extracellular space, pointing to the importance of the transporters that extrude intracellular Ca2+. The family of plasma membrane calcium-dependent ATPases (PMCAs) represent a major component of the Ca2+ regulatory system. However, little information is available on the regional and cellular distribution of these calcium pumps. We used immunohistochemistry to investigate the distribution of each of the four PMCA isoforms (PMCA1-4) in the rat brain. Each isoform exhibited a remarkably precise and distinct pattern of distribution. In many cases, PMCA isoforms in a single brain structure were differentially expressed within different classes of neurons, and within different subcellular compartments. These data show that each isoform is independently organized and suggest that PMCAs may play a more complex role in calcium homeostasis than generally recognized.
Burette
Alain
A
Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA. alain_burette@med.unc.edu
Rockwood
Julia M
JM
Strehler
Emanuel E
EE
Weinberg
Richard J
RJ
D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000201:enzymology*; D001923:Brain Chemistry; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000145:classification / Q000378:metabolism*; D027682:Cation Transport Proteins; D005260:Female; D015151:Immunoblotting / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D053499:Plasma Membrane Calcium-Transporting ATPases; D051381:Rats; D017207:Rats, Sprague-Dawley
D027682:Cation Transport Proteins; D007527:Isoenzymes; D053499:Plasma Membrane Calcium-Transporting ATPases; C506955:Atp2b1 protein, rat; D000252:Calcium-Transporting ATPases; D002118:Calcium