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Polarized distribution of inducible nitric oxide synthase regulates activity in intestinal epithelial cells
Author(s) -
Rumbo Martin,
CourjaultGautier Françoise,
Sierro Frédéric,
Sirard JeanClaude,
FelleyBosco Emanuela
Publication year - 2005
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2004.04484.x
Subject(s) - nitric oxide synthase , cytosol , nitric oxide , chemistry , microbiology and biotechnology , cell , biochemistry , biology , enzyme , organic chemistry
Inducible nitric oxide synthase (iNOS) functions as a homodimer. In cell extracts, iNOS molecules partition both in cytosolic and particulate fractions, indicating that iNOS exists as soluble and membrane associated forms. In this study, iNOS features were investigated in human intestinal epithelial cells stimulated with cytokines and in duodenum from mice exposed to flagellin. Our experiments indicate that iNOS is mainly associated with the particulate fraction of cell extracts. Confocal microscopy showed a preferential localization of iNOS at the apical pole of intestinal epithelial cells. In particulate fractions, iNOS dimers were more abundant than in the cytosolic fraction. Similar observations were seen in mouse duodenum samples. These results suggest that, in epithelial cells, iNOS activity is regulated by localization‐dependent processes.