Human Helios, an Ikaros-related zinc finger DNA binding protein: cDNA cloning and tissue expression pattern

• Published in: Immunogenetics (New York) Vol. 50; no. 1-2; pp. 106 - 108
• Main Authors: Hosokawa, Y, Maeda, Y, Seto, M
• Format: Journal Article
• Language: English
• Published: United States 01.10.1999
• Subjects: Aiolos protein; Amino Acid Sequence; Cloning, Molecular; DNA, Complementary - genetics; DNA-Binding Proteins - genetics; Helios protein; Humans; Ikaros gene; Ikaros Transcription Factor; Molecular Sequence Data; Sequence Homology, Amino Acid; Tissue Distribution; Transcription Factors - genetics; zinc finger proteins; Zinc Fingers
• ISSN: 0093-7711; 1432-1211
• DOI: 10.1007/s002510050696

The molecular mechanisms that control commitment to and progression along the various hematopoietic lineages remain to be elucidated. In many development systems, transcriptional factors act as the principal control genes and are the executors of differentiation programs. The Ikaros gene encodes a family of zinc finger DNA binding proteins and is thought to be a master regulator of lymphocyte differentiation. The main defect of Ikaros-mutant mice is the absence of any sign of B cells, natural killer cells, and of some T-lineage cells, whereas both the erythroid and myeloid lineages appear to remain intact. A second Ikaros gene disruption, which eliminates the DNA-binding domain, results in a more severe lymphopoietic defect: these mice were found to contain no B or T lymphocytes, while the heterozygotes of these mice rapidly developed a clonal lymphoma or leukemia. In addition, the dominant negative and mutant isoforms in the Ikaros gene have been found in infant leukemic cells, implicating that Ikaros is indeed involved in human leukemogenesis. Recently, mouse Aiolos and Helios, Ikaros-related zinc finger proteins, were identified and found to feature the amino acid sequence and functions similar to those of Ikaros. Although Ikaros is present in most hematopoietic cells, Helios has been found primarily in T-cell lineage An intriguing question is whether Helios is involved in the molecular pathogenesis of human T-cell-lymphoid diseases. As a first step toward addressing this relevant issue, we attempted to clone cDNAs encoding human Helios. Our report deals with the cDNA cloning of human Helios and the tissue distribution of its transcript.