Acyl-CoA:lysocardiolipin acyltransferase-1  Acyl-CoA:lysocardiolipin acyltransferase-1 (ALCAT1) is a polyglycerophospholipid acyltransferase of the endoplasmic reticulum which is primarily known for catalyzing the acylation of monolysocardiolipin back into cardiolipin, although it does catalyze the acylation of other polyglycerophospholipids. ALCAT1 is widely distributed throughout the body, with the highest concentrations being in the heart and liver. ALCAT1 facilitates the transfer of acyl groups from linoleoyl-CoA and oleoyl-CoA onto monolysocardiolipin and dilysocardiolipin. The pathway is thought to be important in maintaining heart function, as the ALCAT1 gene is conserved among many species of vertebrates, but not in organisms lacking heart atria. Recent research has shown that ALCAT1 activity is involved with mitochondrial dysfunction in disease. ALCAT1 is upregulated by oxidative stress and diet-induced obesity, and produces a species of cardiolipin that is highly sensitive to oxidative damage. Deficiency of ALCAT1 prevented the onset of diet-induced obesity, improved mitochondria function, and prevented insulin resistance. ALCAT1 was reported to be regulated by thyroid hormone, a universal regulator of metabolism. Its activity also appeared to be inhibited by the presence of ADP and ATP, but not its analogs or other nucleotides, such as UTP and GTP.