The two-pore-domain or tandem pore domain potassium channels are a family of 15 members that form what is known as leak channels which possess
Goldman-Hodgkin-Katz (open)
rectification
Rectification has the following technical meanings:
Mathematics
* Rectification (geometry), truncating a polytope by marking the midpoints of all its edges, and cutting off its vertices at those points
* Rectifiable curve, in mathematics
* Recti ...
.
These channels are regulated by several mechanisms including
signaling lipids,
oxygen tension,
pH,
mechanical stretch, and
G-protein
G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their act ...
s . Their name is derived from the fact that the α subunits consist of four
transmembrane
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...
segments, and each pair of transmembrane segments contains a pore loop between the two transmembrane segments. Thus, each subunit has two pore loops. As such, they structurally correspond to two inward-rectifier α subunits and thus form
dimer
Dimer may refer to:
* Dimer (chemistry), a chemical structure formed from two similar sub-units
** Protein dimer, a protein quaternary structure
** d-dimer
* Dimer model, an item in statistical mechanics, based on ''domino tiling''
* Julius Dimer ( ...
s in the membrane (whereas inward-rectifier α subunits form tetramers).
Each single channel does ''not'' have two pores; the name of the channel comes from the fact that ''each subunit'' has two P (pore) domains in its primary sequence.
To quote Rang and Dale (2015), "The nomenclature is
misleading, especially when they are incorrectly referred to as two-pore channels".
Below is a list of the 15 known two-pore-domain human
potassium channels:
See also
*
Ion channel
Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of io ...
*
Potassium channel
References
External links
*
*
{{protein-stub
Ion channels