Orientation of the β subunit polypeptide of (Na+ + K+)ATPase in the cell membrane

Farley, Robert A.; Miller, Richard P.; Kudrow, A.

doi:10.1016/0167-4838(86)90199-8

Cited by 19 publications

(6 citation statements)

References 17 publications

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“…Actually, at the protein level three isoforms have been identified which differ, among other characteristics, in their tissue distribution, sensitivity to cardiac glycosides, affinity for Na and K, conformational equilibrium between the E1 and E~ state and in hormonal regulation [for review, see 137]. This transmembrane topology is consistent with earlier findings from immunochemical [30,44] and chemical labeling [21] as well as from in vitro translation studies [39]. This transmembrane topology is consistent with earlier findings from immunochemical [30,44] and chemical labeling [21] as well as from in vitro translation studies [39].…”

Section: O~-subunitsupporting

confidence: 77%

Subunit assembly and functional maturation of Na,K-ATPase

1990

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Section: O~-subunitsupporting

confidence: 77%

Subunit assembly and functional maturation of Na,K-ATPase

1990

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“…The ␤-subunit has a total molecular mass of 55 kDa, 35 kDa of which are from the protein component (117). This subunit has one membrane-spanning domain (158,342) and is required for the maturation of the enzyme and its localization in the plasma membrane (767,768). The~10-kDa ␥-subunit was characterized in purified preparations of Na ϩ -K ϩ -ATPase (570), and it is thought to modulate the enzyme's affinity for cations.…”

Section: Basolateral Transportmentioning

confidence: 99%

Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension

Gonzalez‐Vicente

Sáez

Monzón

et al. 2019

Physiological Reviews

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The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.

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“…The ␤ subunit, unlike the ␣ subunit, does not require its association with the ␣ subunit to exit the endoplasmic reticulum (ER) 2 (12,13). The estimated molecular mass of the ␤ 1 subunit is 33.6 kDa in its unglycosylated state, and it is normally about 55 kDa because it contains three sites of extensive glycosylation (14,15). The glycosylation of ␤ 1 subunit, although not necessary for ␣ interaction, is important for ␤ subunit and sodium pump stability, and it has been implicated in affecting cell-cell adhesion (16 -18).…”

mentioning

confidence: 99%

Regulation of Na,K-ATPase Subunit Abundance by Translational Repression

Clifford

Kaplan

2009

Journal of Biological Chemistry

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The Na,K-ATPase is an ␣␤ heterodimer responsible for maintaining fluid and electrolyte homeostasis in mammalian cells. We engineered Madin-Darby canine kidney cell lines expressing ␣ 1 FLAG, ␤ 1 FLAG, or ␤ 2 MYC subunits via a tetracycline-regulated promoter and a line expressing both stable ␤ 1 MYC and tetracycline-regulated ␤ 1 FLAG to examine regulatory mechanisms of sodium pump subunit expression. When overexpression of exogenous ␤ 1 FLAG increased total ␤ subunit levels by >200% without changes in ␣ subunit abundance, endogenous ␤ 1 subunit (␤ 1 E) abundance decreased. ␤ 1 E downregulation did not occur during ␤ 2 MYC overexpression, indicating isoform specificity of the repression mechanism. Measurements of RNA stability and content indicated that decreased ␤ subunit expression was not accompanied by any change in mRNA levels. In addition, the degradation rate of ␤ subunits was not altered by ␤ 1 FLAG overexpression. Cells stably expressing ␤ 1 MYC, when induced to express ␤ 1 FLAG subunits, showed reduced ␤ 1 MYC and ␤ 1 E subunit abundance, indicating that these effects occur via the coding sequences of the down-regulated polypeptides. In a similar way, Madin-Darby canine kidney cells overexpressing exogenous ␣ 1 FLAG subunits exhibited a reduction of endogenous ␣ 1 subunits (␣ 1 E) with no change in ␣ mRNA levels or ␤ subunits. The reduction in ␣ 1 E compensated for ␣ 1 FLAG subunit expression, resulting in unchanged total ␣ subunit abundance. Thus, regulation of ␣ subunit expression maintained its native level, whereas ␤ subunit was not as tightly regulated and its abundance could increase substantially over native levels. These effects also occurred in human embryonic kidney cells. These data are the first indication that cellular sodium pump subunit abundance is modulated by translational repression. This mechanism represents a novel, potentially important mechanism for regulation of Na,K-ATPase expression.

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Orientation of the β subunit polypeptide of (Na+ + K+)ATPase in the cell membrane

Cited by 19 publications

References 17 publications

Subunit assembly and functional maturation of Na,K-ATPase

Subunit assembly and functional maturation of Na,K-ATPase

Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension

Regulation of Na,K-ATPase Subunit Abundance by Translational Repression

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