Differential water permeability and regulation of three aquaporin 4 isoforms

被引：0
作者：
Robert A. Fenton
Hanne B. Moeller
Marina Zelenina
Marteinn T. Snaebjornsson
Torgeir Holen
Nanna MacAulay
机构：
[1] University of Aarhus,The Water and Salt Research Center, Department of Anatomy
[2] Karolinska Institutet,Department of Women’s and Children’s Health
[3] Royal Institute of Technology,Department of Applied Physics
[4] University of Iceland,Department of Anatomy
[5] University of Oslo,Department of Anatomy
[6] University of Copenhagen,Department of Cellular and Molecular Medicine, The Panum Institute
来源：
Cellular and Molecular Life Sciences | 2010年 / 67卷
关键词：
Aquaporin; Glial cells; Water permeability; Regulation; Protein kinase C; Isoforms;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
Aquaporin 4 (AQP4) is expressed in the perivascular glial endfeet and is an important pathway for water during formation and resolution of brain edema. In this study, we examined the functional properties and relative unit water permeability of three functional isoforms of AQP4 expressed in the brain (M1, M23, Mz). The M23 isoform gave rise to square arrays when expressed in Xenopuslaevis oocytes. The relative unit water permeability differed significantly between the isoforms in the order of M1 > Mz > M23. None of the three isoforms were permeable to small osmolytes nor were they affected by changes in external K+ concentration. Upon protein kinase C (PKC) activation, oocytes expressing the three isoforms demonstrated rapid reduction of water permeability, which correlated with AQP4 internalization. The M23 isoform was more sensitive to PKC regulation than the longer isoforms and was internalized significantly faster. Our results suggest a specific role for square array formation.
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页码：829 / 840
页数：11
相关论文
共 236 条
  • [1] Amiry-Moghaddam M(2003)The molecular basis of water transport in the brain Nat Rev Neurosci 4 991-1001
  • [2] Ottersen OP(1997)Specialized membrane domains for water transport in glial cells: high-resolution immunogold cytochemistry of aquaporin-4 in rat brain J Neurosci 17 171-180
  • [3] Nielsen S(2007)Effects of agrin on the expression and distribution of the water channel protein aquaporin-4 and volume regulation in cultured astrocytes Eur J Neurosci 26 2109-2118
  • [4] Nagelhus EA(2009)Role of aquaporin-4 in cerebral edema and stroke Handb Exp Pharmacol 190 159-170
  • [5] Amiry-Moghaddam M(2007)Trafficking and phosphorylation dynamics of AQP4 in histamine-treated human gastric cells Biol Cell 99 25-36
  • [6] Bourque C(2005)Lead induces increased water permeability in astrocytes expressing aquaporin 4 Neuroscience 136 105-114
  • [7] Agre P(2008)Identification of a molecular target for glutamate regulation of astrocyte water permeability Glia 56 587-596
  • [8] Ottersen OP(1998)Regulation of aquaporin-4 water channels by phorbol ester-dependent protein phosphorylation J Biol Chem 273 6001-6004
  • [9] Noell S(2008)Phosphorylation in the C-terminal domain of aquaporin-4 is required for Golgi transition in primary cultured astrocytes Biochem Biophys Res Commun 377 463-468
  • [10] Fallier-Becker P(2001)Polarized trafficking and surface expression of the AQP4 water channel are coordinated by serial and regulated interactions with different clathrin-adaptor complexes EMBO J 20 7008-7021
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