Plasma membrane calcium-transporting ATPase 3
Developmental stage
Expressed in fetal skeletal muscle.
Function
ATP-driven Ca(2+) ion pump involved in the maintenance of basal intracellular Ca(2+) levels at the presynaptic terminals (PubMed:18029012, PubMed:22912398, PubMed:25953895, PubMed:27035656). Uses ATP as an energy source to transport cytosolic Ca(2+) ions across the plasma membrane to the extracellular compartment (PubMed:25953895, PubMed:27035656). May counter-transport protons, but the mechanism and the stoichiometry of this Ca(2+)/H(+) exchange remains to be established (By similarity).
Involvement in disease
Spinocerebellar ataxia, X-linked 1
SCAX1
Spinocerebellar ataxia is a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAX1 is characterized by hypotonia at birth, delayed motor development, gait ataxia, difficulty standing, dysarthria, and slow eye movements. Brain MRI shows cerebellar ataxia.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIB subfamily.
Tissue Specificity
Highly expressed in the cerebellum (PubMed:8187550). Expressed in adrenal glands (PubMed:27035656).
Cellular localization
- Cell membrane
- Multi-pass membrane protein
- Presynaptic cell membrane
- Multi-pass membrane protein
- Localized at parallel fiber terminals.
Alternative names
Plasma membrane calcium-transporting ATPase 3, PMCA3, Plasma membrane calcium ATPase isoform 3, Plasma membrane calcium pump isoform 3, ATP2B3