TY - JOUR
T1 - Raft-like membrane domains contain enzymatic activities involved in the synthesis of mammalian glycosylphosphatidylinositol anchor intermediates
AU - Pielsticker, Liza K.
AU - Mann, Karl J.
AU - Lin, Wen Lang
AU - Sevlever, Daniel
N1 - Funding Information:
This work was supported by NIH Grant DK55002 to D.S. We thank Dr. Terry Rosenberry and M. Sevlever for careful reading of the manuscript.
PY - 2005/4/29
Y1 - 2005/4/29
N2 - The synthesis of the glycosylphosphatidylinositol (GPI) anchor occurs in different compartments within the ER. We have previously shown that GPI anchor intermediates including GlcNAc-PI and GlcN-(acyl)PI are present in Triton insoluble membranes (TIMs), believed to be derived from lipid rafts. The present study was initiated to determine if GPI anchor intermediates move to raft-like domains after their synthesis or if these domains represent another ER compartment for GPI anchor synthesis. We determined that in transfected cells Pig-Ap and Pig-Lp, two proteins involved in the synthesis of GlcNAc-PI and GlcN-PI, respectively, are present in TIMs. In addition, we detected GlcNAc-PI synthase, GlcNAc-PI deacetylase, and GlcN-PI acyltransferase activities in TIMs isolated from untransfected cells. These results lend support to the possibility of additional GPI biosynthetic compartments in the ER and to the notion that GPI anchor intermediates produced in and outside raft-like domains may have a different fate.
AB - The synthesis of the glycosylphosphatidylinositol (GPI) anchor occurs in different compartments within the ER. We have previously shown that GPI anchor intermediates including GlcNAc-PI and GlcN-(acyl)PI are present in Triton insoluble membranes (TIMs), believed to be derived from lipid rafts. The present study was initiated to determine if GPI anchor intermediates move to raft-like domains after their synthesis or if these domains represent another ER compartment for GPI anchor synthesis. We determined that in transfected cells Pig-Ap and Pig-Lp, two proteins involved in the synthesis of GlcNAc-PI and GlcN-PI, respectively, are present in TIMs. In addition, we detected GlcNAc-PI synthase, GlcNAc-PI deacetylase, and GlcN-PI acyltransferase activities in TIMs isolated from untransfected cells. These results lend support to the possibility of additional GPI biosynthetic compartments in the ER and to the notion that GPI anchor intermediates produced in and outside raft-like domains may have a different fate.
KW - GPI
KW - Lipid rafts
KW - Membrane microdomains
KW - Triton insoluble membranes
UR - http://www.scopus.com/inward/record.url?scp=15544382130&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=15544382130&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2005.02.136
DO - 10.1016/j.bbrc.2005.02.136
M3 - Article
C2 - 15781246
AN - SCOPUS:15544382130
SN - 0006-291X
VL - 330
SP - 163
EP - 171
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -