LIG1 Gene

The LIG1 gene (LIG1 stands for "DNA ligase 1") is a protein-coding gene located on chromosome 19q13.33. Alternative splicing results in multiple transcript variants. Mutations in this gene leading to a deficiency of DNA ligase I result in immunodeficiency and increased sensitivity to DNA-damaging substances.

The LIG1 gene encodes a member of the ATP-dependent DNA ligase protein family. Ligases are enzymes that catalyze the joining of two molecules with simultaneous hydrolysis of the diphosphate bond in ATP or a similar triphosphate. They belong to the class of E.C. 6 enzymes, which also includes synthases and carboxylases.

The encoded enzyme has functions in DNA replication, recombination, and base excision repair.

Diseases associated with LIG1 include.

• Immunodeficiency 96
• and
• Bloom syndrome.
• The rs156641 polymorphism in the LIG1 gene appears to be associated with an increased risk of lung cancer (Li D et al. 2015)

1. Barnes DE et al. (1992) Mutations in the DNA ligase I gene of an individual with immunodeficiencies and cellular hypersensitivity to DNA-damaging agents. Cell 69: 495-503.
2. Bentley DJ et al.(2002) DNA ligase I null mouse cells show normal DNA repair activity but altered DNA replication and reduced genome stability. J Cell Sci 115: 1551-1561.
3. Bentley DJ et al. (1996) DNA ligase I is required for fetal liver erythropoiesis but is not essential for mammalian cell viability. Nature Genet 13: 489-491.
4. Li D et al. (2015) Association Between the LIG1 Polymorphisms and Lung Cancer Risk: A Meta-analysis of Case-Control Studies. Cell Biochem Biophys 73:381-387.
5. Maffucci P et al (2018) Biallelic mutations in DNA ligase 1 underlie a spectrum of immune deficiencies. J Clin Invest 128: 5489-5504.
6. Webster ADB et al.(1992) Growth retardation and immunodeficiency in a patient with mutations in the DNA ligase I gene. Lancet 339: 1508-1509.