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Intracellular BK Ca (iBK Ca ) channels
Author(s) -
Singh Harpreet,
Stefani Enrico,
Toro Ligia
Publication year - 2012
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2011.215533
Subject(s) - endoplasmic reticulum , microbiology and biotechnology , intracellular , bk channel , chemistry , golgi apparatus , organelle , mitochondrion , potassium channel , membrane potential , biology , biophysics , biochemistry
The large conductance calcium‐ and voltage‐activated potassium channel (BK Ca ) is widely expressed at the plasma membrane. This channel is involved in a variety of fundamental cellular functions including excitability, smooth muscle contractility, and Ca 2+ homeostasis, as well as in pathological situations like proinflammatory responses in rheumatoid arthritis, and cancer cell proliferation. Immunochemical, biochemical and pharmacological studies from over a decade have intermittently shown the presence of BK Ca in intracellular organelles. To date, intracellular BK Ca (iBK Ca ) has been localized in the mitochondria, endoplasmic reticulum, nucleus and Golgi apparatus but its functional role remains largely unknown except for the mitochondrial BK Ca whose opening is thought to play a role in protecting the heart from ischaemic injury. In the nucleus, pharmacology suggests a role in regulating nuclear Ca 2+ , membrane potential and eNOS expression. Establishing the molecular correlates of iBK Ca , the mechanisms defining iBK Ca organelle‐specific targeting, and their modulation are challenging questions. This review summarizes iBK Ca channels, their possible functions, and efforts to identify their molecular correlates.