Molecular cloning and characterization of a novel human gene containing 4 ankyrin repeat domains.

Ankyrin repeat, one of the most important protein motifs, plays a wide variety of roles in protein-protein interactions and in the signal pathways. Via large-scale sequencing, a novel 941-bp gene was isolated from an 18-week old human fetal brain cDNA library. It encodes a putative protein of 158 amino acid residues with four conserved ankyrin repeat domains. It displays a high degree of homology with rat low-density lipoprotein receptor-related protein 2-binding protein (Lrp2bp), and was therefore was named hLrp2bp (human Lrp2bp). The hLrp2bp gene was located in chromosome 4q35 and the conserved ankyrin repeat domains were located between amino acid residues 10 and 116. RT-PCR revealed that hLrp2bp was mainly expressed in the human testis, small intestine, colon and blood leukocytes, and in human pancreatic adenocarcinoma cells. A HEK293 cell was transfected with the ORF of hLrp2bp, and analyses showed that the protein was distributed both in the cytoplasm and nucleus.