Overview
- Peptide (C)EFHPKPQ(N)QREVPH, corresponding to amino acid residues 10-23 of rat PMCA3 (Accession Q64568). Intracellular, N-terminus.
- Rat and mouse brain membranes (1:200-1:1000).
- Western blot analysis of mouse (lanes 1 and 3) and rat (lanes 2 and 4) brain membranes:1,2. Anti-PMCA3 Antibody (#ACP-003), (1:200).
3,4. Anti-PMCA3 Antibody, preincubated with PMCA3 Blocking Peptide (#BLP-CP003).
- Rat brain sections (1:200).
PMCAs (plasma membrane calcium ATPases) are P-type ATPases, a separate sub-group of Ca2 + pumps responsible for maintain intracellular Ca2+ homeostasis. PMCAs reduce Ca2 + in the cytosol by direct ejection, by controlling the formation of inositol-1,4,5-trisphosphate (IP3), and by decreasing Ca2 + release from the endoplasmic reticulum Ca2+ pool1,2.
Four PMAC proteins are expressed in mammals: PMCA1–4. Alternative splicing produces more than twenty variants that are dissimilar in their regulatory characteristics1,3. PMCA pumps have a C-terminus with a high affinity calmodulin-binding site that also acts as an auto-inhibitor. The C-terminal region also has phosphorylation sites as well as proteolytic sites for caspase-3 and calpain and several motifs that control trafficking of the pump1,2.
PMCA3 is usually present in excitable cells, in the brain and in hair cells of the inner ear or skeletal muscle. The variant is quickly activated and stays active for a long period of time1.