LHFP, a novel translocation partner gene of HMGIC in a lipoma, is a member of a new family of LHFP-like genes

Abstract

A major cytogenetic subgroup among human lipomas is characterized by translocations involving the HMGIC gene at 12q15. In the context of an ongoing research program aiming at the elucidation of the functional consequences of HMGIC translocations in the etiology of lipomas, we have isolated a novel human gene, LHFP (lipoma HMGIC fusion partner), that acts as a translocation partner of HMGIC in a lipoma with t(12;13). The LHFP gene was mapped to the long arm of chromosome 13, a region recurrently targeted by chromosomal aberrations in lipomas. By Northern blot analysis, a transcript of 2. 4 kb was detected in a variety of human tissues. We assembled a cDNA contig containing the entire coding region of LHFP. Nucleotide sequence analysis of the composite LHFP cDNA revealed an open reading frame encoding a protein of 200 amino acids. The predicted human LHFP protein is almost identical to a translated mouse EST that covers almost the entire LHFP coding region. In addition, BLAST searches revealed that the LHFP protein belongs to a new protein family consisting of at least four or five members. In the lipoma studied, the expressed HMGIC/LHFP fusion transcript encodes the three DNA binding domains of HMGIC followed by 69 amino acids encoded by frame-shifted LHFP sequences. LHFP is the second translocation partner of HMGIC identified in lipomas and represents a candidate target gene for lipomas with 13q aberrations.