Proteins containing this domain include mammalian Nit1 and Nit2, the Nit1-like domain of the invertebrate NitFhit, yeast Nit3 and various uncharacterized bacterial and archaeal Nit-like proteins. In general, they are amidases involved in various metabolic processes. Nit1 is a deaminated glutathione amidase [], while Nit2 is an omega-amidase []. They are candidate tumour suppressor proteins []. In NitFhit, the Nit1-like domain is encoded as a fusion protein with the non-homologous tumour suppressor, fragile histidine triad (Fhit) []. Mammalian Nit1 and Fhit may affect distinct signal pathways, and both may participate in DNA damage-induced apoptosis []. Nit1 is a negative regulator in T cells []. Overexpression of Nit2 in HeLa cells leads to a suppression of cell growth through cell cycle arrest in G2 [].
