Hormonal regulation of pituitary GH3 cell K+ channels by Gk is mediated by its α‐subunit
Open Access
- 25 May 1987
- journal article
- Published by Wiley in FEBS Letters
- Vol. 216 (1), 104-106
- https://doi.org/10.1016/0014-5793(87)80765-2
Abstract
The resolved α‐GTPγS (α*) and βγ‐subunits of human erythrocyte Gk, the stimulatory regulatory component of hormone‐responsive K+ channels, were tested for their potential stimulatory activities on the K+ channel of the endocrine GH3 cell. Concentrations as low as 0.5 pM αk* consistently activated K+ channels in isolated membrane patches, and saturating effects were obtained with 50 pM αk*. In contrast 2000–4000 pM βγ was without effect. We conclude that Gk acts on K+ channels through its α‐subunit in a manner akin to that of Gs acting on adenylyl cyclase and transducin acting on cGMP‐specific phosphodiesterase of photo‐receptor cells.Keywords
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