CLONING, EXPRESSION, AND CHROMOSOMAL LOCALIZATION TO 11P12-13 OF A HUMAN LIM HOMEOBOX GENE, HLIM-1/

We have identified a putative transcription factor, designated hLim-1, from human fetal brain using degenerate polymerase chain reaction (PC R) and cDNA library screening, The deduced open reading frame, derived from sequencing a 3.0-kb hLim-1 cDNA, encodes a protein of 384 amino acids with two cysteine-rich LN domains and one homeobox (HOX) DNA-bin ding domain. The nucleotide sequence of hLim-1 cDNA is 87% identical t o mouse Lim-1 and the predicted amino acid sequence is greater than 97 % conserved, Expression patterns of hLim-1 were evaluated by Northern analysis and reverse transcription (RT)-PCR coupled with Southern blot ting, HLim-1 expression was observed in human brain, thymus, and tonsi llar tissue, Expression of hLim-1 was also observed in 58% of acute my elogenous leukemia (AML) cell lines and in four of five primary sample s from patients with chronic myeloid leukemia (CML) in myeloid blast t ransformation, The gene encoding hLim-1 was mapped using fluorescence in situ hybridization (FISH) to human chromosome 11p12-13, The express ion pattern and structural characteristics of the hLim-1 gene suggest that it encodes a transcriptional regulatory protein involved in the c ontrol of differentiation and development of neural and lymphoid cells , Its expression in CML in blast crisis suggests that it may be involv ed with progression in this disease; a prospective study is required t o confirm this.