HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 280, Issue 12, 11656-11664, March 25, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/12/11656    most recent M410987200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, X.-L. Articles by Lee, H.-C. Search for Related Content PubMed PubMed Citation Articles by Wang, X.-L. Articles by Lee, H.-C. Social Bookmarking                      What's this?

Caveolae Targeting and Regulation of Large Conductance Ca²⁺-activated K⁺ Channels in Vascular Endothelial Cells^*

Xiao-Li Wang, Dan Ye, Timothy E. Peterson¶, Sheng Cao, Vijay H. Shah, Zvonimir S. Katusic¶, Gary C. Sieck¶||, and Hon-Chi Lee**

From the Departments of Medicine, ^¶Anesthesiology, and ^||Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905

The vascular endothelium is richly endowed with caveolae, which are specialized membrane microdomains that facilitate the integration of specific cellular signal transduction processes. We found that the large conductance Ca²⁺-activated K⁺ (BK) channels are associated with caveolin-1 in bovine aortic endothelial cells (BAECs). OptiPrep gradient cell fractionation demonstrated that BK channels were concentrated in the caveolae-rich fraction in BAECs. Immunofluorescence imaging showed co-localization of caveolin-1 and BK channels in the BAEC membrane. Immunoprecipitation and glutathione S-transferase pull-down assay results indicated that caveolin-1 and BK channels are physically associated. However, whole cell patch clamp recordings could not detect BK (iberiotoxin-sensitive) currents in cultured BAECs under baseline conditions, even though the presence of BK mRNA and protein expression was confirmed by reverse transcription-PCR and Western blots. Cholesterol depletion redistributed the BK channels to non-caveolar fractions of BAECs, resulting in BK channel activation (7.3 ± 1.6 pA/picofarad (pF), n = 5). BK currents were also activated by isoproterenol (ISO, 1 µM, 6.9 ± 2.4 pA/pF, n = 6). Inclusion of a caveolin-1 scaffolding domain peptide (10 µM) in the pipette solution completely abrogated the effects of ISO on BK channel activation, whereas inclusion of the scrambled control peptide (10 µM) did not inhibit the ISO effects. We have also found that caveolin-1 knockdown by small interference RNA activated BK currents (5.3 ± 1.4 pA/pF, n = 6). We conclude that: 1) BK channels are targeted to caveolae microdomains in vascular endothelial cells; 2) caveolin-1 interacts with BK channels and exerts a negative regulatory effect on channel functions; and 3) BK channels are inactive under control conditions but can be activated by cholesterol depletion, knockdown of caveolin-1 expression, or ISO stimulation. These novel findings may have important implications for the role of BK channels in the regulation of endothelial function.

Received for publication, September 24, 2004 , and in revised form, December 27, 2004.

^* This work was supported by National Institutes of Health Grants HL-63754 and HL-74180 (to H. L.) and the Mayo Clinic Foundation. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Both authors contributed equally to this work.

^** To whom correspondence should be addressed: Division of Cardiovascular Diseases, Dept. of Internal Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN 55905. Tel.: 507-255-8353; Fax: 507-255-7070; E-mail: lee.honchi{at}mayo.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				S. Langlois, K. N. Cowan, Q. Shao, B. J. Cowan, and D. W. Laird Caveolin-1 and -2 Interact with Connexin43 and Regulate Gap Junctional Intercellular Communication in Keratinocytes Mol. Biol. Cell, March 1, 2008; 19(3): 912 - 928. [Abstract] [Full Text] [PDF]

				J. Saliez, C. Bouzin, G. Rath, P. Ghisdal, F. Desjardins, R. Rezzani, L.F. Rodella, J. Vriens, B. Nilius, O. Feron, et al. Role of Caveolar Compartmentation in Endothelium-Derived Hyperpolarizing Factor-Mediated Relaxation: Ca2+ Signals and Gap Junction Function Are Regulated by Caveolin in Endothelial Cells Circulation, February 26, 2008; 117(8): 1065 - 1074. [Abstract] [Full Text] [PDF]

				A. Alioua, R. Lu, Y. Kumar, M. Eghbali, P. Kundu, L. Toro, and E. Stefani Slo1 Caveolin-binding Motif, a Mechanism of Caveolin-1-Slo1 Interaction Regulating Slo1 Surface Expression J. Biol. Chem., February 22, 2008; 283(8): 4808 - 4817. [Abstract] [Full Text] [PDF]

				A. K. Weaver, M. L. Olsen, M. B. McFerrin, and H. Sontheimer BK Channels Are Linked to Inositol 1,4,5-Triphosphate Receptors via Lipid Rafts: A NOVEL MECHANISM FOR COUPLING [Ca2+]i TO ION CHANNEL ACTIVATION J. Biol. Chem., October 26, 2007; 282(43): 31558 - 31568. [Abstract] [Full Text] [PDF]

				S. A. Predescu, D. N. Predescu, and A. B. Malik Molecular determinants of endothelial transcytosis and their role in endothelial permeability Am J Physiol Lung Cell Mol Physiol, October 1, 2007; 293(4): L823 - L842. [Abstract] [Full Text] [PDF]

				D.-L. Dong, Y. Zhang, D.-H. Lin, J. Chen, S. Patschan, M. S. Goligorsky, A. Nasjletti, B.-F. Yang, and W.-H. Wang Carbon Monoxide Stimulates the Ca2+ Activated Big Conductance K Channels in Cultured Human Endothelial Cells Hypertension, October 1, 2007; 50(4): 643 - 651. [Abstract] [Full Text] [PDF]

				K. Yamamoto, N. Shimizu, S. Obi, S. Kumagaya, Y. Taketani, A. Kamiya, and J. Ando Involvement of cell surface ATP synthase in flow-induced ATP release by vascular endothelial cells Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1646 - H1653. [Abstract] [Full Text] [PDF]

				S. Tikku, Y. Epshtein, H. Collins, A. J. Travis, G. H. Rothblat, and I. Levitan Relationship between Kir2.1/Kir2.3 activity and their distributions between cholesterol-rich and cholesterol-poor membrane domains Am J Physiol Cell Physiol, July 1, 2007; 293(1): C440 - C450. [Abstract] [Full Text] [PDF]

				A. Shmygol, K. Noble, and S. Wray Depletion of membrane cholesterol eliminates the Ca2+-activated component of outward potassium current and decreases membrane capacitance in rat uterine myocytes J. Physiol., June 1, 2007; 581(2): 445 - 456. [Abstract] [Full Text] [PDF]

				H. Couchoux, B. Allard, C. Legrand, V. Jacquemond, and C. Berthier Loss of caveolin-3 induced by the dystrophy-associated P104L mutation impairs L-type calcium channel function in mouse skeletal muscle cells J. Physiol., May 1, 2007; 580(3): 745 - 754. [Abstract] [Full Text] [PDF]

				L. Tian, L. Chen, H. McClafferty, C. A. Sailer, P. Ruth, H.-G. Knaus, and M. J. Shipston A noncanonical SH3 domain binding motif links BK channels to the actin cytoskeleton via the SH3 adapter cortactin FASEB J, December 1, 2006; 20(14): 2588 - 2590. [Abstract] [Full Text] [PDF]

				T. Lu, D. Ye, X. Wang, J. M. Seubert, J. P. Graves, J. A. Bradbury, D. C. Zeldin, and H.-C. Lee Cardiac and vascular KATP channels in rats are activated by endogenous epoxyeicosatrienoic acids through different mechanisms J. Physiol., September 1, 2006; 575(2): 627 - 644. [Abstract] [Full Text] [PDF]

				X. Cheng and J. H. Jaggar Genetic ablation of caveolin-1 modifies Ca2+ spark coupling in murine arterial smooth muscle cells Am J Physiol Heart Circ Physiol, June 1, 2006; 290(6): H2309 - H2319. [Abstract] [Full Text] [PDF]

				N. Ullrich, A. Caplanusi, B. Brone, D. Hermans, E. Lariviere, B. Nilius, W. Van Driessche, and J. Eggermont Stimulation by caveolin-1 of the hypotonicity-induced release of taurine and ATP at basolateral, but not apical, membrane of Caco-2 cells Am J Physiol Cell Physiol, May 1, 2006; 290(5): C1287 - C1296. [Abstract] [Full Text] [PDF]

				R. Lu, A. Alioua, Y. Kumar, M. Eghbali, E. Stefani, and L. Toro MaxiK channel partners: physiological impact J. Physiol., January 1, 2006; 570(1): 65 - 72. [Abstract] [Full Text] [PDF]