The nuclear localization signal of zebrafish terra is located within the DM domain

Zebrafish Terra is a member of the DM domain-containing transcription facto r family and is involved in somitogenesis. The other known members of this family play a role in sex differentiation across species from Caenorhabditi s elegans to human. Using the green fluorescence protein-Terra fusion const ructs, we have identified the nuclear localization Signal (NLS) of terra by transfecting human HeLa cells. The terra NLS is located between the two in tertwined zinc-binding sites of the DNA-binding domain. However, the nuclea r translocation of terra is independent of the structure required for DNA b inding. Mutational analysis demonstrates that basic residues K77 and R78 wi thin the DM domain are absolutely required for the translocation of Terra i nto the nuclei. Sequence comparison discloses that the NLS of Terra is also present in the other known members of the DM family, indicating the conser vative nature of the NLS of this family during evolution. ((C) 2001 Publish ed by Elsevier Science B.V. on behalf of the Federation of European Biochem ical Societies.