ATP8A2
Function
Catalytic component of a P4-ATPase flippase complex which catalyzes the hydrolysis of ATP coupled to the transport of aminophospholipids from the outer to the inner leaflet of various membranes and ensures the maintenance of asymmetric distribution of phospholipids (By similarity). Able to translocate phosphatidylserine, but not phosphatidylcholine (PubMed:34403372). Phospholipid translocation seems also to be implicated in vesicle formation and in uptake of lipid signaling molecules (By similarity). Reconstituted to liposomes, the ATP8A2:TMEM30A flippase complex predominantly transports phosphatidylserine (PS) and to a lesser extent phosphatidylethanolamine (PE) (By similarity). Phospholipid translocation is not associated with a countertransport of an inorganic ion or other charged substrate from the cytoplasmic side toward the exoplasm in connection with the phosphorylation from ATP (By similarity). ATP8A2:TMEM30A may be involved in regulation of neurite outgrowth (By similarity). Proposed to function in the generation and maintenance of phospholipid asymmetry in photoreceptor disk membranes and neuronal axon membranes (By similarity). May be involved in vesicle trafficking in neuronal cells (By similarity). Required for normal visual and auditory function; involved in photoreceptor and inner ear spiral ganglion cell survival (By similarity).
Involvement in disease
Cerebellar ataxia, impaired intellectual development, and dysequilibrium syndrome 4
CAMRQ4
An autosomal recessive, congenital cerebellar ataxia associated with dysarthia, quadrupedal gait and intellectual disability.
None
The disease is caused by variants affecting the gene represented in this entry.
A chromosomal aberration disrupting ATP8A2 has been found in a patient with severe intellectual disability and major hypotonia. Translocation t(10;13)(p12.1;q12.13) (PubMed:20683487).
Sequence Similarities
Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IV subfamily.
Tissue Specificity
Strongly expressed in the brain, cerebellum, retina and testis.
Cellular localization
- Membrane
- Multi-pass membrane protein
- Golgi apparatus membrane
- Endosome membrane
- Cell membrane
- Photoreceptor outer segment membrane
- Photoreceptor inner segment membrane
- Localizes to the Golgi and endosomes in photoreceptor cells (By similarity). Localizes to disk membranes of rod photoreceptor outer segments (ROS) (By similarity).
Alternative names
ATPIB, ATP8A2, Phospholipid-transporting ATPase IB, ATPase class I type 8A member 2, ML-1, P4-ATPase flippase complex alpha subunit ATP8A2