P-type ATPases

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Phosphorylation-type ATPases (EC 3.6.3.-) are associated with membranes and the transport of ions or phospholipids. A characteristic is the interconversion between E1 and E2 conformations in the activity cycle of the transporters.


Na+/K+-ATPase


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The cell-surface Na+/K+-ATPase is an integral membrane protein which regulates the membrane potential of the cell by maintaining gradients of Na+ and K+ ions across the plasma membrane, also making a small, direct contribution to membrane potential, particularly in cardiac cells. The active enzyme is a heteromultimer with incompletely defined stoichiometry, possibly as tetramers of heterodimers, each consisting of one of four large, ten TM domain catalytic α subunits and one of three smaller single TM domain glycoprotein β-subunits (see table). Additional protein partners known as FXYD proteins (e.g. FXYD2, ENSG00000137731) appear to associate with and regulate the activity of the pump.


Unless otherwise stated all data refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).

Transporters

α1 Show »

α2 Show »

α3 Show »

α4 Show »

β1 Show »

β2 Show »

β3 Show »


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Ca2+-ATPases


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The sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) is an intracellular membrane-associated pump for sequestering calcium from the cytosol into intracellular organelles, usually associated with the recovery phase following excitation of muscle and nerves.

The plasma membrane Ca2+-ATPase (PMCA) is a cell-surface pump for extruding calcium from the cytosol, usually associated with the recovery phase following excitation of cells. The active pump is a homodimer, each subunit of which is made up of ten TM segments, with cytosolic C- and N-termini and two large intracellular loops.

Secretory pathway Ca2+-ATPases (SPCA) allow accumulation of calcium and manganese in the Golgi apparatus.


Unless otherwise stated all data refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).

Transporters

SERCA1 Show »

SERCA2 Show »

SERCA3 Show »

PMCA1 Show »

PMCA2 Show »

PMCA3 Show »

PMCA4 Show »

SPCA1 Show »

SPCA2 Show »


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H+/K+-ATPase


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The H+/K+ ATPase is a heterodimeric protein, made up of α and β subunits. The α subunit has 10 TM domains and exhibits catalytic and pore functions, while the β subunit has a single TM domain, which appears to be required for intracellular trafficking and stabilising the α subunit. The ATP4A and ATP4B subunits are expressed together, while the ATP12A subunit is suggested to be expressed with the β1 (ATP1B1) subunit of the Na+/K+-ATPase [5].


Unless otherwise stated all data refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).

Transporters

ATP4A Show »

ATP12A Show »

ATP4B Show »


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Cu2+-ATPase


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Copper-transporting ATPases convey copper ions across cell-surface and intracellular membranes. They consist of eight TM domains and associate with multiple copper chaperone proteins (e.g. ATOX1, ENSG00000177556).


Unless otherwise stated all data refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).

Transporters

ATP7A Show »

ATP7B Show »


Phospholipid-transporting ATPase


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These transporters are thought to translocate the aminophospholipids phosphatidylserine and phosphatidylethanolamine from one side of the phospholipid bilayer to the other.


Unless otherwise stated all data refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).

Transporters

ATP8A1 Show »

ATP8A2 Show »

ATP8B1 Show »

ATP8B2 Show »

ATP8B3 Show »

ATP8B4 Show »

ATP9A Show »

ATP9B Show »

ATP10A Show »

ATP10B Show »

ATP10D Show »

ATP11A Show »

ATP11B Show »

ATP11C Show »


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