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potassium inwardly-rectifying channel, subfamily J, member 6
Kcnj6 : potassium inwardly-rectifying channel, subfamily J, member 6
The activation of GIRK channels is mediated by a pertussis toxin-sensitive G protein, via a direct membrane-delimited pathway without involving intracellular second messenger systems. The G-beta-gamma subunit plays an important physiological role in the activation by direct binding to multiple regions of GIRK channels (Huang ). Signaling via the G-protein-mediated pathway is regulated by a recently identified gene family, known to encode RGS proteins (regulators of G-protein signaling) (Druey ).
RGS4 reduces the basal GIRK1/GIRK2 current and strongly increases the percentage agonist-evoked K+ conductance. RGS4 reconstitutes the native gating kinetics by accelerating GIRK1/GIRK2 channel deactivation. Ulens 
GIRK2 but not GIRK3 can be activated by G protein subunits Gj3, and G-y2 in Xenopus oocytes. Kofuji 
Kir3.2 ( = GIRK2) is important for opioid receptor transmission. Loetsch 
The importance of the strong expression of Kir3.2 in midbrain neurons is documented by the fact that a point mutation in the pore of the mouse Kir3.2 channel, leading to a loss of ion selectivity, results in the weaver (wv) phenotype. Such mice suffer from aberrant postnatal development and death of several classes of neurons including the dopaminergic neurons of the SNc (Liao et al., 1996 ; Surmeier et al., 1996 ).
The heterogeneously distributed Kir3.2 channel proteins could help to discriminate the dopaminergic neurons of ventral tegmental area and substantia nigra pars compacta. Eulitz