Torsin-1A-interacting protein 1 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''TOR1AIP1''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. More commonly known as

lamina Lamina may refer to: Science and technology * Planar lamina, a two-dimensional planar closed surface with mass and density, in mathematics * Laminar flow, (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption betwee ...

associated polypeptide 1 (LAP1), it is a type II

integral membrane protein An integral, or intrinsic, membrane protein (IMP) is a type of membrane protein that is permanently attached to the biological membrane. All ''transmembrane proteins'' are IMPs, but not all IMPs are transmembrane proteins. IMPs comprise a signi ...

that resides in the inner nuclear membrane. The luminal domain of LAP1 interacts with

Torsin A Torsin-1A (TorA) also known as dystonia 1 protein (DYT1) is a protein that in humans is encoded by the ''TOR1A'' gene (also known as DQ2 or DYT1). TorA localizes to the endoplasmic reticulum and contiguous perinuclear space The nuclear envel ...

and is necessary for the ATPase activity of

. LAP1 plays a critical role in skeletal and heart muscle. Mutations in ''TOR1AIP1'' have been linked to

muscular dystrophy Muscular dystrophies (MD) are a genetically and clinically heterogeneous group of rare neuromuscular diseases that cause progressive weakness and breakdown of skeletal muscles over time. The disorders differ as to which muscles are primarily affe ...

and

cardiomyopathy Cardiomyopathy is a group of diseases that affect the heart muscle. Early on there may be few or no symptoms. As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure. A ...

. It's deletion from mouse hepatocytes leads to defected very-low density lipoprotein secretion and causes

non-alcoholic fatty liver disease Non-alcoholic fatty liver disease (NAFLD), also known as metabolic (dysfunction) associated fatty liver disease (MAFLD), is excessive fat build-up in the liver without another clear cause such as alcohol use. There are two types; non-alcoholic ...

and

non-alcoholic steatohepatitis Non-alcoholic fatty liver disease (NAFLD), also known as metabolic (dysfunction) associated fatty liver disease (MAFLD), is excessive fat build-up in the liver without another clear cause such as alcohol use. There are two types; non-alcoholic ...

Shin JY, Hernandez-Ono A, Fedotova T, Östlund C, Lee MJ, Gibeley SB, Liang CC, Dauer WT, Ginsberg HN, Worman HJ. (2019) Nuclear envelope-localized torsinA-LAP1 complex regulates hepatic VLDL secretion and steatosis. ''J Clin Invest''. 130:4885-4900. doi: 10.1172/JCI129769.

References

Further reading