Trex1 gene

Acronym for "Three prime repair exonuclease 1" gene (located on the short arm of chromosome 3). The gene encodes an important, phylogenetically early intracellular DNase (TREX1) (see nucleases below), which is involved in the degradation of unused DNA or DNA fragments created in preparation for replication. TREX1 plays an important role in apoptosis, DNA repair and other processes. TREX1 is a key component of the SET complex, a multitasking protein involved in transcription, nucleosome construction, and histone binding. The exonuclease TREX1 is found in all organisms, from unicellular organisms (e.g. yeasts) to mammals.

Eukaryotes are characterized by the fact that various processes take place in specialized, separated areas (compartments) of the cells. In the cell nucleus, for example, DNA is stored in certain compartments, while in another compartment proteins are synthesized according to the instructions defined in the genome. In order to send the genetic information from the cell nucleus into the cytoplasm, a copy of the genetic material, the "messenger RNA" (mRNA), is created. After transcription and synthesis, the mRNA is modified several times at the gene site before it can finally be "matured" and transported into the cytoplasm. Even during the transcription phase, proteins attach themselves to the resulting precursor mRNA in order to "package" it and make it transportable for export into the cytoplasm. The TREX complex is involved in this process. So far, > 32 different mutations of the TREX1 gene have been identified.

Mutations of the TREX1 gene lead to the incorrect function of the TREX1-encoded proteins. The result is an uncontrolled (currently still unexplained) immune response of the organism with the formation of autoantibodies. Current data suggest that mutations of the TREX1 gene play a role in Sjögren's syndrome, familial Chilblain lupus, systemic lupus erythematosus, and Aicardi-Goutières syndrome.

1. Pfeiffer C (2011). Systemic lupus erythematosus with cutaneous involvement in a patient with heterozygous TREX1 mutation. Abstract Volume 46, Conference DDG P10/07.
2. Namjou B (2011). Evaluation of the TREX1 gene in a large multi-ancestral lupus cohort. Genes and Immunity: 1-10 www.nature.com/gene
3. Mazur DJ, Perrino FW (2001). Structure and expression of the TREX1 and TREX2 3'-5' exonuclease genes. J Biol Chem; 276: 14718-14727