Physiological and nutritional regulation of enzymes of triacylglycerol synthesis

Although triacylglycerol stores play the critical role in an organism's abi lity to withstand fuel deprivation and are strongly associated with such di sorders as diabetes, obesity, and atherosclerotic heart disease, informatio n concerning the enzymes of triacylglycerol synthesis, their regulation by hormones, nutrients, and physiological conditions, their mechanisms of acti on, and the roles of specific isoforms has been limited by a lack of cloned cDNAs and purified proteins. Fortunately, molecular tools for several key enzymes in the synthetic pathway are becoming available. This review summar izes recent studies of these enzymes, their regulation under varying physio logical conditions, their purported roles in synthesis of triacylglycerol a nd related glycerolipids, the possible functions of different isoenzymes, a nd the evidence for specialized cellular pools of triacylglycerol and glyce rolipid intermediates.