PR Domain Containing Protein 16 (PRDM16)

The 1,257-amino acid MEL1 protein shares 56% amino acid identity with MDS1/EVI1 and has a similar domain structure. The first 222 amino acids of MEL1 are highly homologous to the PR domain of MDS1 , and the rest of the MEL1 sequence is homologous to EVI1. Following the N-terminal PR domain, MEL1 has a zinc finger DNA-binding domain, a proline-rich domain, a repressor domain, a second zinc finger DNA-binding domain, and a C-terminal acidic domain. Northern blot and RT-PCR analyses of various leukemia cell lines revealed a major 8-kb MEL1 transcript only in cells with t(1;3). In human tissues, RT-PCR showed MEL1 expression only in uterus and fetal kidney. MEL1 and MEL1S had apparent molecular masses of 170 and 150 kD, respectively, and t(1;3)-positive leukemias expressed predominantly MEL1S protein.