|
|
|
|||||||
|
|||||||||
J. Biol. Chem., Vol. 278, Issue 4, 2713-2722, January 24, 2003
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From the Department of Physiology, School of Medicine, The Johns
Hopkins University, Baltimore, Maryland 21205
The large conductance, voltage- and
Ca2+-activated K+ channel (MaxiK) is
expressed in several renal segments and functions in cell volume
regulation and flow-mediated K+ secretion. Previously, we
cloned two MaxiK channel isoforms, named rbslo1 and rbslo2, from rabbit
renal cells. rbslo1 has a 58-amino acid insertion after the S8
hydrophobic domain, whereas rbslo2 is truncated and cannot be
activated. Here we use the sequence differences between the two
variants to examine their plasma membrane processing. Plasma membrane
localization of rbslo1 and 2 expressed in HEK293 cells was assayed by
electrophysiology, immunocytochemistry, and biochemistry studies.
Consistent with its functional silence, rbslo2 localized primarily
within the cytoplasm, presumably in the endoplasmic reticulum and Golgi
region. Coexpression with MaxiK
The Cytoplasmic Tail of Large Conductance, Voltage- and
Ca2+-activated K+ (MaxiK) Channel Is Necessary
for Its Cell Surface Expression*
subunits did not alter the cellular
localization of either rbslo1 or rbslo2. When rbslo1 and 2 are
cotransfected in non-polarized cells, they colocalized primarily within
the cell with only rbslo1 detected at the plasma membrane. When
transfected into polarized, medullary-thick ascending limb (mTAL)
cells, rbslo1 is expressed at the apical membrane whereas the majority
of rbslo2 localized throughout the cytoplasm. Given the high degree of
similarity between the two isoforms, we conclude that the cytoplasmic
tail of rbslo1 is important for the cell surface expression of MaxiK channels.
*
This work was supported by National Institutes of Health
Grant DK32753.The costs of publication of this
article were defrayed in part by the
payment of page charges. The article
must therefore be hereby marked
"advertisement" in
accordance with 18 U.S.C. Section
1734 solely to indicate this fact.
To whom correspondence should be addressed: Dept. of Physiology,
School of Medicine, The Johns Hopkins University, Wood Basic Science
Bldg. 214A, 725 N. Wolfe St., Baltimore, MD 21205. Tel.: 410-955-7166; Fax: 410-955-0461; E-mail: wguggino@jhmi.edu.
Copyright © 2003 by The American Society for Biochemistry and Molecular Biology, Inc.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  A. M. Dopico and D. M. Lovinger Acute Alcohol Action and Desensitization of Ligand-Gated Ion Channels Pharmacol. Rev., March 1, 2009; 61(1): 98 - 114. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Estilo, W. Liu, N. Pastor-Soler, P. Mitchell, M. D. Carattino, T. R. Kleyman, and L. M. Satlin Effect of aldosterone on BK channel expression in mammalian cortical collecting duct Am J Physiol Renal Physiol, September 1, 2008; 295(3): F780 - F788. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Y. Kim, K.-J. Choi, and S. E. Dryer Nephrin binds to the COOH terminus of a large-conductance Ca2+-activated K+ channel isoform and regulates its expression on the cell surface Am J Physiol Renal Physiol, July 1, 2008; 295(1): F235 - F246. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Zou, S. Jha, E. Y. Kim, and S. E. Dryer A Novel Actin-Binding Domain on Slo1 Calcium-Activated Potassium Channels Is Necessary for Their Expression in the Plasma Membrane Mol. Pharmacol., February 1, 2008; 73(2): 359 - 368. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Liu, T. Morimoto, C. Woda, T. R. Kleyman, and L. M. Satlin Ca2+ dependence of flow-stimulated K secretion in the mammalian cortical collecting duct Am J Physiol Renal Physiol, July 1, 2007; 293(1): F227 - F235. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H.-J. Kim, H.-H. Lim, S.-H. Rho, S. H. Eom, and C.-S. Park Hydrophobic Interface between Two Regulators of K+ Conductance Domains Critical for Calcium-dependent Activation of Large Conductance Ca2+-activated K+ Channels J. Biol. Chem., December 15, 2006; 281(50): 38573 - 38581. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. M. Satlin, M. D. Carattino, W. Liu, and T. R. Kleyman Regulation of cation transport in the distal nephron by mechanical forces Am J Physiol Renal Physiol, November 1, 2006; 291(5): F923 - F931. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Najjar, H. Zhou, T. Morimoto, J. B. Bruns, H.-S. Li, W. Liu, T. R. Kleyman, and L. M. Satlin Dietary K+ regulates apical membrane expression of maxi-K channels in rabbit cortical collecting duct Am J Physiol Renal Physiol, October 1, 2005; 289(4): F922 - F932. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Brainard, A. J. Miller, J. R. Martens, and S. K. England Maxi-K channels localize to caveolae in human myometrium: a role for an actin-channel-caveolin complex in the regulation of myometrial smooth muscle K+ current Am J Physiol Cell Physiol, July 1, 2005; 289(1): C49 - C57. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S.-H. Kwon and W. B. Guggino Multiple sequences in the C terminus of MaxiK channels are involved in expression, movement to the cell surface, and apical localization PNAS, October 19, 2004; 101(42): 15237 - 15242. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. B. Woda, N. Miyawaki, S. Ramalakshmi, M. Ramkumar, R. Rojas, B. Zavilowitz, T. R. Kleyman, and L. M. Satlin Ontogeny of flow-stimulated potassium secretion in rabbit cortical collecting duct: functional and molecular aspects Am J Physiol Renal Physiol, October 1, 2003; 285(4): F629 - F639. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |