Format

Send to

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2004 Aug 27;279(35):37115-23. Epub 2004 Jun 10.

pH microdomains in oligodendrocytes.

Author information

  • 1Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030, USA.

Abstract

Oligodendrocytes (OLs) are cells that produce myelin in the central nervous system. Here we use ratiometric pH indicator dye to analyze intracellular pH in OLs in culture. The results reveal alkaline microdomains, which predominate in the perikaryon and proximal dendrites, and acidic microdomains, which predominate in distal dendrites. Spatial nonuniformity of pH is generated by differential subcellular distribution of Na(+)/H(+) exchanger (NHE), which is localized in a punctate distribution in the perikaryon and proximal processes, Na(+)/HCO(3)(-) cotransporter (NBC), which is localized in a punctate distribution in distal dendrites, and carbonic anhydrase isotype II (CAII), which is colocalized with either NHE or NBC. Inhibition of NHE activity by amiloride inhibits regeneration of alkaline microdomains after cytoplasmic acidification, whereas the inhibition of CAII activity with ethoxyzolamide inhibits acidification of dendrites. Fluorescence correlation spectroscopy analysis of CAII microinjected into OLs reveals freely diffusing protein throughout the cell as well as protein associated predominantly with NHE in the perikaryon and predominantly with NBC in the dendrites. Alkaline and acidic microdomains could be generated by transport metabolons consisting of CAII associated with NHE or NBC, respectively. This study provides the first evidence for pH microdomains in cells and describes a mechanism for how they are generated.

PMID:
15192115
DOI:
10.1074/jbc.M403099200
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center