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Colocalization of leukotriene C synthase and microsomal glutathione S‐transferase elucidated by indirect immunofluorescence analysis
Author(s) -
Surapureddi Sailesh,
Svartz Jesper,
Magnusson Karl-Eric,
Hammarström Sven,
Söderström Mats
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01885-8
Subject(s) - leukotriene c4 , microsome , glutathione , microbiology and biotechnology , colocalization , transferase , biology , biochemistry , glutathione s transferase , subcellular localization , atp synthase , immunofluorescence , enzyme , endoplasmic reticulum , leukotriene , chemistry , cytoplasm , antibody , asthma , immunology
We have previously shown that the two membrane bound enzymes leukotriene C synthase and microsomal glutathione S‐transferase interact in vitro and in vivo. Rat basophilic leukemia cells and murine mastocytoma cells, two well‐known sources of leukotriene C synthase, both expressed microsomal glutathione S‐transferase as determined by Western blot analyses. Several human tissues were found to contain both leukotriene C synthase and microsomal glutathione S‐transferase mRNA. These data suggest that the interaction may be physiologically important. To study this further, expression vectors encoding the two enzymes were cotransfected into mammalian cells and the subcellular localization of the enzymes was determined by indirect immunofluorescence using confocal laser scanning microscopy. The results showed that leukotriene C synthase and microsomal glutathione S‐transferase were both localized on the nuclear envelope and adjacent parts of the endoplasmic reticulum. Image overlay demonstrated virtually identical localization. We also observed that coexpression substantially reduced the catalytic activity of each enzyme suggesting that a mechanism involving protein–protein interaction may contribute to the regulation of LTC 4 production.