Plays a role in the regulation of lipogenesis in liver. Up-regulates ACACA enzyme activity. Required for efficient lipid biosynthesis, including triacylglycerol, diacylglycerol and phospholipid. Involved in stabilization of microtubules. Homodimer in the absence of THRSP. Heterodimer with THRSP. The homodimer interacts with ACACA and ACACB. Promotes polymerization of Acetyl-CoA carboxylase to form complexes that contain MID1IP1 and ACACA and/or ACACB. Interaction with THRSP interferes with ACACA binding. Associated with microtubules (PubMed:15070402). During embryonic development, expressed mainly in the neuroepithelial midline, urogenital apparatus and digits. Detected in adult white fat, liver, heart, brain and kidney. Expressed at very low levels in lactating mammary gland. Down-regulated by fasting. Up-regulated by a carbohydrate-rich diet. Belongs to the SPOT14 family. It is uncertain whether Met-1 or Met-2 is the initiator.