Threonine Aspartase 1 (TASP1)

Threonine aspartase 1 is an endopeptidase that cleaves specific substrates following aspartate residues. The encoded protein undergoes posttranslational autoproteolytic processing to generate alpha and beta subunits, which reassemble into the active alpha2-beta2 heterotetramer. It is required to cleave MLL, a protein required for the maintenance of HOX gene expression, and TFIIA, a basal transcription factor. Alternatively spliced transcript variants have been described, but their biological validity has not been determined.Tasp1 -/- mouse embryos were smaller than wildtype or heterozygous mice as early as embryonic day 14.5, and Tasp1 -/- mice that survived the newborn period were smaller through adulthood. Tasp1 -/- animals displayed profound skeletal abnormalities, including classic homeotic transformations of vertebrae and ribs.