Pertussis-toxin-sensitive Gα subunits selectively bind to C-terminal domain of neuronal GIRK channels: evidence for a heterotrimeric G-protein-channel complex

Selective Gαi Subunits as Novel Direct Activators of Transient Receptor Potential Canonical (TRPC)4 and TRPC5 Channels

“…1-4 indicate that activation of G␣ i subunits by GPCRs is the primary mechanism for activating TRPC4 and TRPC5. This raised the question of whether activation of the channels requires direct interaction with the G␣ i subunits, as was shown for other channels regulated by G␣ (36) and G␤␥ (33,37) subunits. To address this question, we identified the TRPC4 and TRPC5 domain that might interact with the G␣ i subunits.…”

Structural Basis for Modulation of Gating Property of G Protein-gated Inwardly Rectifying Potassium Ion Channel (GIRK) by i/o-family G Protein α Subunit (Gαi/o)

“…Previously, the G␣ i/o binding regions in GIRK1 were investigated by pulldown assays using the cytoplasmic fragments of GIRK (14,15,20,22,24). The cytoplasmic C-terminal residues 320 -369 of GIRK1 were indicated to be important for strong binding to G␣ i3 (14), whereas the N-terminal fragment of GIRK1 (residues 1-84) also bound to G␣ i/o (GTP) (15,20).…”

Coregulation of Natively Expressed Pertussis Toxin-Sensitive Muscarinic Receptors with G-Protein-Activated Potassium Channels

“…Because of the coupling of G␣ o subunits with Kir3 channels (Leaney and Tinker, 2000;Ivanina et al, 2004;Clancy et al, 2005), we hypothesized that Kir3 channels may be upregulated in NGF-differentiated PC12 cells. To examine this, we used qRT-PCR, a very sensitive method for quantifying mRNA levels in living cells.…”

“…Stimulation of receptors that couple to PTX-insensitive G-proteins (e.g., G␣ q and G␣ s ), conversely, do not activate Kir3 channels (Yamada et al, 1998). The direct interaction of G␣ i/o subunits with Kir3 channels may be important for establishing specific PTX-sensitive GPCR/Kir3 signaling pathways (Slesinger et al, 1995;Ivanina et al, 2004;Clancy et al, 2005).…”