Any feedback?
Literature summary for 7.6.2.1 extracted from
- Localization, purification, and functional reconstitution of the P4-ATPase Atp8a2, a phosphatidylserine flippase in photoreceptor disc membranes (2009), J. Biol. Chem., 284, 32670-32679.
Activating Compound
| Activating Compound | Comment | Organism | Structure |
|---|---|---|---|
| additional information | no activation by phosphatidylcholine or other membrane lipids | Bos taurus | |
| phosphatidylethanolamine | activates to a lesser degree | Bos taurus |  |
| phosphatidylserine | - |
Bos taurus | |
Cloned(Commentary)
| Cloned (Comment) | Organism |
|---|---|
| gene atp8a2, DNA and amino acid sequence determination and analysis, expression in HEK-293 cells | Mus musculus |
| gene atp8a2, DNA and amino acid sequence determination and analysis, expression in HEK-293 cells | Homo sapiens |
| gene atp8a2, DNA and amino acid sequence determination and analysis, expression of 1D4-tagged Atp8a2 in HEK-293 cells | Bos taurus |
Inhibitors
| Inhibitors | Comment | Organism | Structure |
|---|---|---|---|
| additional information | no inhibition by ouabain and azide | Bos taurus | |
| NEM | over 90% inhibition of ATPase activity at 1 mM | Bos taurus | |
| vanadate | over 90% inhibition of ATPase activity at 0.1 mM | Bos taurus | |
KM Value [mM]
| KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| additional information | - |
additional information | kinetics, overview | Homo sapiens | |
| additional information | - |
additional information | Michaelis-Menten kinetics, overview | Bos taurus | |
| 0.704 | - |
ATP | pH 7.5, 37°C | Homo sapiens | |
Localization
| Localization | Comment | Organism | GeneOntology No. | Textmining |
|---|---|---|---|---|
| membrane | - |
Mus musculus | 16020 | - |
| membrane | - |
Homo sapiens | 16020 | - |
| membrane | - |
Bos taurus | 16020 | - |
| additional information | localization study by immunofluorescence microscopy | Homo sapiens | - |
- |
| additional information | localization study by immunofluorescence microscopy | Bos taurus | - |
- |
Metals/Ions
| Metals/Ions | Comment | Organism | Structure |
|---|---|---|---|
| Mg2+ | required | Mus musculus | |
| Mg2+ | required | Homo sapiens | |
| Mg2+ | required | Bos taurus | |
Molecular Weight [Da]
| Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
|---|---|---|---|
| 132000 | - |
x * 132000, about, recombinant enzyme, SDS-PAGE | Homo sapiens |
| 132000 | - |
x * 132000, recombinant enzyme, SDS-PAGE | Bos taurus |
Natural Substrates/ Products (Substrates)
| Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| ATP + H2O + phosphatidylethanolamine/in | Bos taurus | - |
ADP + phosphate + phosphatidylethanolamine/out | - |
? | |
| ATP + H2O + phosphatidylserine/in | Bos taurus | - |
ADP + phosphate + phosphatidylserine/out | - |
? | |
| ATP + H2O + phospholipid/in | Mus musculus | - |
ADP + phosphate + phospholipid/out | - |
? | |
| ATP + H2O + phospholipid/in | Homo sapiens | - |
ADP + phosphate + phospholipid/out | - |
? | |
| additional information | Mus musculus | Atp8a2 flipps fluorescent-labeled phosphatidylserine from the inner leaflet of liposomes, equivalent to the exocytoplasmic leaflet of cell membranes, to the outer leaflet, equivalent to cytoplasmic leaflet, in an ATP-dependent manner | ? | - |
? | |
| additional information | Homo sapiens | Atp8a2 flipps fluorescent-labeled phosphatidylserine from the inner leaflet of liposomes, equivalent to the exocytoplasmic leaflet of cell membranes, to the outer leaflet, equivalent to cytoplasmic leaflet, in an ATP-dependent manner | ? | - |
? | |
| additional information | Bos taurus | Atp8a2 flipps fluorescent-labeled phosphatidylserine from the inner leaflet of liposomes, equivalent to the exocytoplasmic leaflet of cell membranes, to the outer leaflet, equivalent to cytoplasmic leaflet, in an ATP-dependent manner | ? | - |
? | |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Bos taurus | C7EXK4 | gene atp8a2 | - |
| Homo sapiens | Q9NTI2 | gene atp8a2 | - |
| Mus musculus | P98200 | C57/B6 and BALB/c mice, gene atp8a2 | - |
Purification (Commentary)
| Purification (Comment) | Organism |
|---|---|
| native Atp8a2 1887fold from photoreceptor outer segments by immunoaffinity chromatography | Bos taurus |
| recombinant enzyme from HEK-293 cells by immunoaffinity chromatography | Homo sapiens |
Renatured (Commentary)
| Renatured (Comment) | Organism |
|---|---|
| purified Atp8a2 is reconstituted into liposomes containing fluorescent-labeled phosphatidylserine to measure the ability of Atp8a2 to flip phosphatidylserine across the lipid bilayer. 30% of the reconstituted Atp8a2 is inaccessible to trypsin and correspondingly ATP | Bos taurus |
Source Tissue
| Source Tissue | Comment | Organism | Textmining |
|---|---|---|---|
| additional information | localization study by immunofluorescence microscopy | Homo sapiens | - |
| additional information | localization study by immunofluorescence microscopy | Bos taurus | - |
| photoreceptor cell | disc membranes | Mus musculus | - |
| photoreceptor cell | disc membranes | Homo sapiens | - |
| photoreceptor cell | disc membranes | Bos taurus | - |
| retina | outer segment disc membranes of rod and cone photoreceptor cells | Mus musculus | - |
| retina | outer segment disc membranes of rod and cone photoreceptor cells, high expression of atp8a2 | Homo sapiens | - |
| retina | outer segment disc membranes of rod and cone photoreceptor cells, high expression of atp8a2 | Bos taurus | - |
| testis | - |
Mus musculus | - |
| testis | high expression of atp8a2 | Homo sapiens | - |
| testis | high expression of atp8a2 | Bos taurus | - |
Specific Activity [micromol/min/mg]
| Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
|---|---|---|---|
| 0.054 | - |
purified native enzyme, pH 7.5, 37°C | Bos taurus |
| 35 | - |
purified native enzyme reconstituted in lipid vesicles, pH 7.5, 37°C | Bos taurus |
| 45 | 55 | purified lipid-stimulated enzyme, pH 7.5, 37°C | Homo sapiens |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| ATP + H2O + phosphatidylethanolamine/in | - |
Bos taurus | ADP + phosphate + phosphatidylethanolamine/out | - |
? | |
| ATP + H2O + phosphatidylethanolamine/in | the enzyme is specific for ATP and shows no activity with GTP, AMP-PNP, GDP, or ADP | Bos taurus | ADP + phosphate + phosphatidylethanolamine/out | - |
? | |
| ATP + H2O + phosphatidylserine/in | - |
Bos taurus | ADP + phosphate + phosphatidylserine/out | - |
? | |
| ATP + H2O + phosphatidylserine/in | the enzyme is specific for ATP and shows no activity with GTP, AMP-PNP, GDP, or ADP | Bos taurus | ADP + phosphate + phosphatidylserine/out | - |
? | |
| ATP + H2O + phospholipid/in | - |
Mus musculus | ADP + phosphate + phospholipid/out | - |
? | |
| ATP + H2O + phospholipid/in | - |
Homo sapiens | ADP + phosphate + phospholipid/out | - |
? | |
| additional information | Atp8a2 flipps fluorescent-labeled phosphatidylserine from the inner leaflet of liposomes, equivalent to the exocytoplasmic leaflet of cell membranes, to the outer leaflet, equivalent to cytoplasmic leaflet, in an ATP-dependent manner | Mus musculus | ? | - |
? | |
| additional information | Atp8a2 flipps fluorescent-labeled phosphatidylserine from the inner leaflet of liposomes, equivalent to the exocytoplasmic leaflet of cell membranes, to the outer leaflet, equivalent to cytoplasmic leaflet, in an ATP-dependent manner | Homo sapiens | ? | - |
? | |
| additional information | Atp8a2 flipps fluorescent-labeled phosphatidylserine from the inner leaflet of liposomes, equivalent to the exocytoplasmic leaflet of cell membranes, to the outer leaflet, equivalent to cytoplasmic leaflet, in an ATP-dependent manner | Bos taurus | ? | - |
? | |
| additional information | dithionite NBD-lipid assay for detection of flippase activity | Homo sapiens | ? | - |
? | |
| additional information | dithionite NBD-lipid assay for detection of flippase activity | Bos taurus | ? | - |
? | |
Subunits
| Subunits | Comment | Organism |
|---|---|---|
| ? | x * 132000, about, recombinant enzyme, SDS-PAGE | Homo sapiens |
| ? | x * 132000, recombinant enzyme, SDS-PAGE | Bos taurus |
Synonyms
| Synonyms | Comment | Organism |
|---|---|---|
| Atp8a2 | - |
Mus musculus |
| Atp8a2 | - |
Homo sapiens |
| Atp8a2 | - |
Bos taurus |
| More | the enzyme belongs to the P4-ATPase subfamily of the of P-type ATPases | Mus musculus |
| More | the enzyme belongs to the P4-ATPase subfamily of the of P-type ATPases | Homo sapiens |
| More | the enzyme belongs to the P4-ATPase subfamily of the of P-type ATPases | Bos taurus |
| P4-ATPase | - |
Mus musculus |
| P4-ATPase | - |
Homo sapiens |
| P4-ATPase | - |
Bos taurus |
| phosphatidylserine flippase | - |
Mus musculus |
| phosphatidylserine flippase | - |
Homo sapiens |
| phosphatidylserine flippase | - |
Bos taurus |
Temperature Optimum [°C]
| Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
|---|---|---|---|
| 23 | - |
flippase assay at | Homo sapiens |
| 23 | - |
flippase assay at | Bos taurus |
| 37 | - |
ATPase assay at | Homo sapiens |
| 37 | - |
ATPase assay at | Bos taurus |
pH Optimum
| pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
|---|---|---|---|
| 7 | 9 | with substrate phosphatidylserine | Bos taurus |
| 7.5 | - |
assay at | Homo sapiens |
| 8 | - |
with substrate phosphatidylethanolamine | Bos taurus |
General Information
| General Information | Comment | Organism |
|---|---|---|
| physiological function | P4-ATPases in general are implicated in the energy-dependent translocation of aminophospholipids across cell membranes. Atp8a2 is implicated in the generation and maintenance of phosphatidylserine asymmetry in photoreceptor disc membranes | Mus musculus |
| physiological function | P4-ATPases in general are implicated in the energy-dependent translocation of aminophospholipids across cell membranes. Atp8a2 is implicated in the generation and maintenance of phosphatidylserine asymmetry in photoreceptor disc membranes | Homo sapiens |
| physiological function | P4-ATPases in general are implicated in the energy-dependent translocation of aminophospholipids across cell membranes. Atp8a2 is implicated in the generation and maintenance of phosphatidylserine asymmetry in photoreceptor disc membranes | Bos taurus |
Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.
Release 2023.1 (January 2023)
Legal
Curated at
Member of
