Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins.
ATP-sensitive potassium channel complex
A protein complex that comprises four pore-forming (Kir6.x) and four regulatory sulphonylurea receptor (SURx) subunits and forms a transmembrane channel through which ions may pass. The opening and closing of the channel is regulated by ATP: binding of ATP to the Kir6.2 subunit inhibits channel activity, whereas binding of Mg2+-complexed ATP or ADP to the SUR1 subunit stimulates channel activity.
The outer membrane of a muscle cell, consisting of the plasma membrane, a covering basement membrane (about 100 nm thick and sometimes common to more than one fiber), and the associated loose network of collagen fibers.
Any of the small, heterogeneous, artifactual, vesicular particles, 50-150 nm in diameter, that are formed when some eukaryotic cells are homogenized and that sediment on centrifugation at 100000 g.
The contractile element of skeletal and cardiac muscle; a long, highly organized bundle of actin, myosin, and other proteins that contracts by a sliding filament mechanism.
A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.
integral to membrane
Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane.
KATP channels -of which Kir6.1 is a key unit - are inhibited
by increasing intracellular [ATP] and activated by
increasing [ADP]. (Ng )
The KATP channel opener
diazoxide increased reactive oxygen species production,
and glibenclamide abolished this effect. However, in cells
lacking Kir6.1 or expressing siRNA or dominant negative
constructs of Kir6.1, the same effect was seen. (Ng )
The KATP channel is
an octameric complex comprised of four Kir6.0 subunits
from the inward rectifier family of potassium channels and
four sulfonylurea receptors (SURs), a member of the ATP-
binding cassette family of proteins. The pore-forming sub-
unit Kir6.0 has two different members, Kir6.1 and Kir6.2,
which share 70% amino acid identity. The regulatory sub-
unit SUR is encoded by two distinct genes, SUR1 and
SUR2, and is the site of action for antidiabetic drugs such as
glibenclamide used in the treatment of type 2 diabetes
mellitus (Babenko et al. 1998 ; Seino 1999 ; Rodrigo and
Standen 2005 ; Ashcroft and Gribble 1998 ).
KATP channels - of which kKr6.1 is a key unit - are present on endomembranes, in particular in mitochondria (‘‘mitoKATP’’)
(Inoue et al. 1991 ; Paucek et al. 1992 ).
showed that a major proportion of heterologously expressed Kir6.1-GFP and endogenously expressed Kir6.1 was
distributed in the endoplasmic reticulum with little in the
mitochondria or plasma membrane. (Ng )
ATP-sensitive potassium (KATP) channels - of which Kir6.1 is a central unit - are involved in a
number of physiological and pathophysiological processes
and form a link between cellular metabolism and membrane
excitability. (Ng )
Kir6.1 plays a
role in modifying Ca2+ release from intracellular stores. (Ng )