Lipid kinase that can phosphorylate both monoacylglycerol and diacylglycerol to form lysophosphatidic acid (LPA) and phosphatidic acid (PA), respectively . Does not phosphorylate sphingosine . Phosphorylates ceramide (By similarity). Phosphorylates 1,2-dioleoylglycerol more rapidly than 2,3-dioleoylglycerol (By similarity). Independently of its lipid kinase activity, acts as a component of the TIM22 complex (, ). The TIM22 complex mediates the import and insertion of multi-pass transmembrane proteins into the mitochondrial inner membrane by forming a twin-pore translocase that uses the membrane potential as the external driving force (, ). In the TIM22 complex, required for the import of a subset of metabolite carriers into mitochondria, such as ANT1/SLC25A4 and SLC25A24, while it is not required for the import of TIMM23 . Overexpression increases the formation and secretion of LPA, resulting in transactivation of EGFR and activation of the downstream MAPK signaling pathway, leading to increased cell growth .
Subcellular locations: Mitochondrion inner membrane, Mitochondrion intermembrane space
Localizes in the mitochondrion intermembrane space, where it associates with the inner membrane . It is unclear whether the N-terminal hydrophobic region forms a transmembrane region or associates with the membrane without crossing it (, ).
Highly expressed in muscle, heart, kidney and brain.