Table I.
Human PMCA isoforms and major alternative splice variants
| Isoform | Major alternative splice variants |
Length in amino acids |
GenBank accession numbers |
Tissue distribution |
|---|---|---|---|---|
| PMCA1 | PMCA1x/a | 1176 | NM_001001323 | Brain, nervous tissue |
| PMCA1x/b | 1220 | NM_001682 | Ubiquitous | |
| PMCA1x/c | 1249 | Skeletal muscle, heart | ||
| PMCA2 | PMCA2w/a | 1199 | U15688* | Inner ear hair cells |
| PMCA2x/a | 1168 | Brain (relatively rare) | ||
| PMCA2z/a | 1154 | Brain (generally more abundant than 2x/a) | ||
| PMCA2w/b | 1243 | NM_001001331 | Brain, breast (lactating mammary gland), pancreatic β-cells | |
| PMCA2x/b | 1212 | Brain/excitable tissue | ||
| PMCA2z/b | 1198 | NM_001683 | Brain/excitable tissue | |
| PMCA3 | PMCA3x/a | 1173 | NM_021949 | Brain |
| PMCA3z/a | 1159 | Brain (cortex, thalamus, substantia nigra), pancreatic β-cells | ||
| PMCA3x/b | 1220 | NM_001001344 | Brain | |
| PMCA3z/b | 1206 | Brain (cortex, thalamus, substantia nigra) | ||
| PMCA3x/f | 1129 | (Fast) skeletal muscle, brain (rare) | ||
| PMCA4 | PMCA4x/a | 1170 | NM_001001396 | Brain, heart, stomach |
| PMCA4z/a | 1158 | Heart, pancreas (Islet of Langerhans) | ||
| PMCA4x/b | 1205 | NM_001684 | Ubiquitous | |
| PMCA4z/b | 1193 | Heart | ||
*
Splice site C alternative exon sequence only