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Albumin stimulates lysophosphatidic acid acyltransferase activity in T‐lymphocyte membranes
Author(s) -
Jolly Christopher A.,
Kannan Latha
Publication year - 2002
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-002-0920-4
Subject(s) - phosphatidic acid , lysophosphatidic acid , acyltransferase , biochemistry , lymphocyte , albumin , biology , chemistry , phospholipid , membrane , enzyme , immunology , receptor
Phosphatidic acid (PtdOH) and lysophosphatidic acid (lysoPtdOH) have been shown to enhance T‐lymphocyte function. However, the FA preference and influence of acyl‐CoA binding proteins on lysoPtdOH and PtdOH biosynthesis are not known. Therefore, we determined glycerol‐3‐phosphate acyltransferase (GPAT) and lysophosphatidic acid acyltransferase (LAT) activity in rat T‐lymphocyte and liver membrane preparations in the presence of palmitoyl‐CoA and oleoyl‐CoA with or without BSA. We found two different properties of GPAT and LAT in whole T‐lymphocyte membrane preparations relative to liver. First, T‐lymphocyte basal GPAT and LAT activities were similar, whereas in liver membranes LAT activity was 10‐fold higher than GPAT. Second, T‐lymphocyte LAT, but not GPAT, activity was inducible (fivefold) by the addition of albumin in the presence of palmitoyl‐CoA but not oleoyl‐CoA. In contrast, albumin stimulated GPAT, but not LAT, activity in liver membranes in the presence of palmitoyl‐CoA. These results show, for the first time, that T‐lymphocyte LAT activity can be increased by the presence of an acyl‐CoA binding protein, which may indicate a new important control mechanism for regulating intracellular lysoPtdOH and PtdOH levels in T‐lymphocytes.