Functional Expression of the Colonic H+,K+-ATPase α-Subunit

Codina, Juan; Kone, Bruce C.; Delmas-Mata, Juan T.; DuBose, Thomas D.

doi:10.1074/jbc.271.47.29759

Cited by 84 publications

(58 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Finally, when the antibody was incubated overnight with 2000 g of membranes prepared from renal medulla of chronically hypokalemic rats (condition shown to enhance the expression of HK␣ 2 in these membranes), there was a decrease in the intensity of the band on the immunoblot. This finding indicates that HK␣ 2 is present in membranes from the renal medulla during hypokalemia but, as expected, in less abundance than in the distal colon (6).…”

Section: ␤-Subunit Of Hk␣mentioning

confidence: 58%

“…Although the findings of Lee and associates (3) suggested that under certain conditions HK␣ 2 may function in the absence of a ␤-subunit, the study by Cougnon and associates (4) and that from our laboratory (5), cited above, demonstrated, nevertheless, that under certain physiological conditions different ␤-subunits may interact with HK␣ 2 . The interaction of HK␣ 2 with various ␤-subunits observed in heterologous systems does not necessarily reveal what may pertain in intact tissues, however.…”

mentioning

confidence: 76%

“…To explore the relevance of this observation in vivo, membranes (1 mg) were prepared from the renal medulla of rats after chronic dietary K ϩ depletion (chronic hypokalemia), a condition known to maximize H ϩ ,K ϩ -ATPase expression in kidney (6,7). These membranes were incubated overnight with anti-HK␣ 2 antibody (150 l) (see "Experimental Procedures").…”

Section: Resultsmentioning

confidence: 99%

“…ing that the levels of HK␣ 2 are either very low or absent from the renal cortex of normal rats (6). Finally, when the antibody was incubated overnight with 2000 g of membranes prepared from renal medulla of chronically hypokalemic rats (condition shown to enhance the expression of HK␣ 2 in these membranes), there was a decrease in the intensity of the band on the immunoblot.…”

Section: ␤-Subunit Of Hk␣mentioning

confidence: 99%

“…In contrast a different pharmacologic profile was observed when HK␣ 2 was expressed in oocytes from Xenopus laevis (4,5). Cougnon and associates (4) employed the ␤-subunit from toad bladder, for which there is no known mammalian counterpart.…”

mentioning

confidence: 99%

See 4 more Smart Citations

The α-Subunit of the Colonic H+,K+-ATPase Assembles with β1-Na+,K+-ATPase in Kidney and Distal Colon

Codina¹,

Delmas-Mata²,

DuBose³

1998

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Section: ␤-Subunit Of Hk␣mentioning

confidence: 58%

mentioning

confidence: 76%

Section: Resultsmentioning

confidence: 99%

Section: ␤-Subunit Of Hk␣mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

The α-Subunit of the Colonic H+,K+-ATPase Assembles with β1-Na+,K+-ATPase in Kidney and Distal Colon

Codina¹,

Delmas-Mata²,

DuBose³

1998

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Colonic Potassium Absorption and Secretion in Health and Disease

Rajendran

Sandle

2018

Comprehensive Physiology

View full text Add to dashboard Cite

The colon has large capacities for K absorption and K secretion, but its role in maintaining K homeostasis is often overlooked. For many years, passive diffusion and/or solvent drag were thought to be the primary mechanisms for K absorption in human and animal colon. However, it is now clear that apical H ,K -ATPase, in coordination with basolateral K -Cl cotransport and/or K and Cl channels operating in parallel, mediate electroneutral K absorption in animal colon. We now know that K absorption in rat colon reflects ouabain-sensitive and ouabain-insensitive apical H ,K -ATPase activities. Ouabain-insensitive and ouabain-sensitive H ,K -ATPases are localized in surface and crypt cells, respectively. Colonic H ,K -ATPase consists of α- (HKC ) and β- (HKC ) subunits which, when coexpressed, exhibit ouabain-insensitive H ,K -ATPase activity in HEK293 cells, while HKC coexpressed with the gastric β-subunit exhibits ouabain-sensitive H ,K -ATPase activity in Xenopus oocytes. Aldosterone enhances apical H ,K -ATPase activity, HKC specific mRNA and protein expression, and K absorption. Active K secretion, on the other hand, is mediated by apical K channels operating in a coordinated way with the basolateral Na -K -2Cl cotransporter. Both Ca -activated intermediate conductance K (IK) and large conductance K (BK) channels are located in the apical membrane of colonic epithelia. IK channel-mediated K efflux provides the driving force for Cl secretion, while BK channels mediate active (e.g., cAMP-activated) K secretion. BK channel expression and activity are increased in patients with end-stage renal disease and ulcerative colitis. This review summarizes the role of apical H ,K -ATPase in K absorption, and apical BK channel function in K secretion in health and disease. © 2018 American Physiological Society. Compr Physiol 8:1513-1536, 2018.

show abstract