MTTP Gene

The MTTP gene (MTTP stands for "Microsomal Triglyceride Transfer Protein") is a protein-coding gene located on chromosome 4q23.

The MTTP gene encodes the large subunit of the heterodimeric microsomal triglyceride transfer protein. Protein disulfide isomerase (PDI) completes the heterodimeric microsomal triglyceride transfer protein, which has been shown to play a central role in lipoprotein assembly.

The encoded protein disulfide isomerase catalyzes the transport of triglyceride, cholesteryl ester, and phospholipid between phospholipid surfaces (Khatun I et al. (2013). The enzyme is required for the assembly and secretion of plasma lipoproteins containing apolipoprotein B (Khatun I et al. 2013; Rehberg EF et al. 1996). Furthermore, it may be involved in the regulation of cholesterol ester biosynthesis in cells producing lipoproteins.

Diseases associated with MTTP include abetalipoproteinemia and abdominal obesity-metabolic syndrome 1.

• Khatun I et al (2013) Loss of both phospholipid and triglyceride transfer activities of microsomal triglyceride transfer protein in abetalipoproteinemia. J Lipid Res 54:1541-1549.
• Rehberg EF et al (1996) A novel abetalipoproteinemia genotype. Identification of a missense mutation in the 97-kDa subunit of the microsomal triglyceride transfer protein that prevents complex formation with protein disulfide isomerase. J Biol Chem 271:29945-29952.