TARDBP, as known as TAR DNA binding protein, was originally identified as a transcriptional repressor that binds to chromosomally integrated TAR DNA and represses HIV-1 transcription. It has also been identified in individuals diagnosed with chronic traumatic encephalopathy, a condition that often mimics ALS and that has been associated with athletes who have experienced multiple concussions and other types of head injury. It has been shown to bind both DNA and RNA and have multiple functions in transcriptional repression, pre-mRNA splicing and translational regulation. Recombinant human TARDBP protein protein, fused to His-tag at N-terminus, was expressed in E.coli.