The membrane organization of leukotriene synthesis.
Cell signaling leading to the formation of leukotriene (LT)C(4) requires the localization of the four key biosynthetic enzymes on the outer nuclear membrane and endoplasmic reticulum. Whether any macromolecular organization of these proteins exists is unknown. By using fluorescence lifetime imaging microscopy and biochemical analysis, we demonstrate the presence of two distinct multimeric complexes that regulate the formation of LTs in RBL-2H3 cells. One complex consists of multimers of LTC(4) synthase and the 5-lipoxygenase activating protein (FLAP). The second complex consists of multimers of FLAP. Surprisingly, all LTC(4) synthase was found to be in association with FLAP. The results indicate that the formation of LTC(4) and LTB(4) may be determined by the compartmentalization of biosynthetic enzymes in discrete molecular complexes.
Mandal
Asim K
AK
Department of Medicine, Massachusetts General Hospital, 149 The Navy Yard, 13th Street, Charlestown, MA 02129, USA.
Skoch
Jesse
J
Bacskai
Brian J
BJ
Hyman
Bradley T
BT
Christmas
Peter
P
Miller
Douglas
D
Yamin
Ting-ting D
TT
Xu
Shihua
S
Wisniewski
Douglas
D
Evans
Jilly F
JF
Soberman
Roy J
RJ
D058927:5-Lipoxygenase-Activating Proteins; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004735:Energy Transfer; D006801:Humans; D017997:Leukotriene C4 / Q000096:biosynthesis* / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence
D058927:5-Lipoxygenase-Activating Proteins; C548592:ALOX5AP protein, human; D002352:Carrier Proteins; D008565:Membrane Proteins; D017997:Leukotriene C4