- Author:
- Shelley Fong <sfon036@UoA.auckland.ac.nz>
- Date:
- 2024-09-12 13:54:06+12:00
- Desc:
- Init
- Permanent Source URI:
- https://models.physiomeproject.org/workspace/bd1/rawfile/40fc74f7c5e3ea82b4155115dc64cfb4d2ff6182/exposure/exposure_frontpage.rst
About
====================
Landing page for the proteins constituting the transient outward potassium current (**TO**).
This channel transports potassium ions across the plasma membrane according to the concentration gradient. It is crucial in the early repolarisation of the cell membrane during the cardiac action potential, as it rapidly activates and inactivates following membrane depolarization
There are 2 variants for this current: fast I\ :sub:`to, f` and slow I\ :sub:`to, s`
**TO** channels are tetramers of pore-forming alpha subunits.
Pictures
===================
.. figure:: exposure/6m85_assembly-1.jpeg
:width: 50%
:align: center
:alt: KIR2.2
Fig. 1. Visualisation of the KIR2.2 channel. Image from the RCSB PDB (RCSB.org) of PDB ID 1BNA (H.R. Drew, R.M. Wing, T. Takano, C. Broka, S. Tanaka, K. Itakura, R.E.Dickerson, Structure of a B-DNA dodecamer: conformation and dynamics (1981) Proc.Natl.Acad.Sci.USA 78: 2179-2183)
Subfamilies
===================
The following list contains the known proteins which may form the **TO** current.
.. csv-table:: Variants within the human species
:header: "Name", "Alias", Current, Gene, Structure, Interacts with
:widths: 4,4, 7,7,7, 9
KCND2, Kv4.2, fast, `Uniprot D2 <https://www.uniprot.org/uniprotkb/Q9NZV8/entry>`_, `PDB D2 <https://www.ebi.ac.uk/pdbe-srv/view/entry/7E7Z>`_, KCND3/KChIP2/DPP6
KCND3, Kv4.3, fast, `Uniprot D3 <https://www.uniprot.org/uniprotkb/Q9UK17/entry>`_, `SMR D3 <https://swissmodel.expasy.org/repository/uniprot/Q9UK17?csm=ADD1402A97204764>`_, KCND2/KChIP2/DPP6
KCNA4, Kv1.4, slow, `Uniprot A4 <https://www.uniprot.org/uniprotkb/P22459/entry>`_, `SMR A4 <https://swissmodel.expasy.org/repository/uniprot/P22459?csm=5E511DB704CCA013>`_,
KCNA7, Kv1.7, slow, `Uniprot A7 <https://www.uniprot.org/uniprotkb/Q96RP8/entry>`_, `SMR A7 <https://swissmodel.expasy.org/repository/uniprot/Q96RP8?csm=EF9980CF54D52FB8>`_,
Literature
===================
.. csv-table:: For further reading
:header: "Title", "Author"
:widths: 30, 15
"`The Molecular Physiology of the Cardiac Transient Outward Potassium Current (Ito) in Normal and Diseased Myocardium <https://doi.org/10.1006%2Fjmcc.2001.1376>`_", "Oudit et al."
"`Novel mechanism of transient outward potassium channel current regulation in the heart: implications for cardiac electrophysiology in health and disease <https://doi.org/10.1161/circresaha.115.306438>`_", "Bohnen et al."
Existing models
===================
.. csv-table:: Link to other PMR workspaces or exposures
:header: "Title", "Author"
:widths: 30, 15
"`BG_TO <https://models.physiomeproject.org/workspace/82e>`_", "S Fong"
"`A computational model of induced pluripotent stem-cell derived cardiomyocytes incorporating experimental variability from multiple data sources*^ <https://doi.org/10.1113/JP278739>`_", "Kernik et al."
Models denoted by [*] are not in bond graph form.
Models denoted by [^] are part of a whole cell model.
Other annotations
===================
.. csv-table::
:header: "Item", "Database"
:widths: 17, 15
