Year: 2007
Type: article
Abstract: Recent studies have ascribed many non-pumping functions to the Na/K-ATPase. Here, we present experimental evidence demonstrating that over half of the plasma membrane Na/K-ATPase in LLC-PK1 cells is performing cellular functions other than ion pumping. This "non-pumping" pool of Na/K-ATPase, like the pumping pump, binds ouabain. Depletion of either cholesterol or caveolin-1 moves some of the "non-pumping" Na/K-ATPase into the pumping pool. Graded knock-down of the alpha1 subunit of the Na/K-ATPase eventually results in loss of this "non-pumping" pool while preserving the pumping pool. Our prior studies indicate that a loss of the non-pumping pool is associated with a loss of receptor function as evidenced by the failure of ouabain administration to induce the activation of Src and/or ERK. Therefore, our new findings suggest that a substantial amount of surface-expressed Na/K-ATPase, at least in some types of cells, may function as non-canonical ouabain-binding receptors.
Source: Journal of Biological Chemistry
Authors: Man Liang, Jiang Tian, Lijun Liu, Sandrine Pierre, Jiang Liu, Joseph Shapiro, Zi-Jian Xie
Institution: University of Toledo
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W2122252852