Effect of cell swelling on membrane and cytoplasmic distribution of pI(Cln)

Francesco Emma, Sylvie Breton, Rebecca Morrison, Stephen Wright, Kevin Strange

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

pI(Cln) is found ubiquitously in mammalian cells and is postulated to play a critical role in cell volume regulation. Mutagenesis studies led to the proposal that pI(Cln) is a swelling-activated anion channel. However, recent studies in Madin-Darby canine kidney cells and endothelial cells have shown that the protein is localized primarily to the cytoplasm. It has therefore been postulated that activation involves reversible translocation of pI(Cln) from the cytoplasm and insertion into the plasma membrane. We tested this hypothesis using several different approaches. Fractionation of C6 glioma cells into plasma membrane- and cytoplasm-containing fractions demonstrated that ~90% of the recovered pI(Cln) was confined to the cytosol. Swelling had no effect on the relative amount of protein present in the plasma membrane fraction. Immunofluorescence microscopy revealed that pI(Cln) is localized primarily, if not exclusively, to the cytoplasm of swollen and nonswollen cells. Similarly, transfection of cells with a green fluorescent protein-labeled pI(Cln) construct failed to reveal any membrane localization of the protein. These findings do not support the hypothesis that pI(Cln) is a volume regulatory anion channel activated by swelling-induced membrane insertion.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume274
Issue number6 43-6
StatePublished - Jun 1998

Fingerprint

Cell membranes
Swelling
Cytoplasm
Cell Membrane
Membranes
Anions
Mutagenesis
Proteins
Madin Darby Canine Kidney Cells
Endothelial cells
Fractionation
Green Fluorescent Proteins
Cell Size
Fluorescence Microscopy
Glioma
Cytosol
Transfection
Microscopic examination
Membrane Proteins
Endothelial Cells

Keywords

  • Anion channels
  • Cell volume regulation
  • Organic osmolytes
  • Osmoregulation

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Cell Biology
  • Physiology
  • Physiology (medical)

Cite this

Effect of cell swelling on membrane and cytoplasmic distribution of pI(Cln). / Emma, Francesco; Breton, Sylvie; Morrison, Rebecca; Wright, Stephen; Strange, Kevin.

In: American Journal of Physiology - Cell Physiology, Vol. 274, No. 6 43-6, 06.1998.

Research output: Contribution to journalArticle

Emma, Francesco ; Breton, Sylvie ; Morrison, Rebecca ; Wright, Stephen ; Strange, Kevin. / Effect of cell swelling on membrane and cytoplasmic distribution of pI(Cln). In: American Journal of Physiology - Cell Physiology. 1998 ; Vol. 274, No. 6 43-6.
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