ABCC13, an unusual truncated ABC transporter, is highly expressed in fetal human liver.

In the present study, we have cloned the cDNA of ABCC13, a novel ABC transporter, from the cDNA library of adult human placenta. The ABCC13 gene spans approximately 70kb on human chromosome 21q11.2 and consists of 14 exons. The open reading frame of the ABCC13 cDNA encodes a peptide consisting of 325 amino acid residues. The amino acid sequence corresponding to putative membrane-spanning domains was remarkably similar to ABCC1, ABCC2, ABCC3, and ABCC6. The ABCC13 gene was expressed in the fetal liver at the highest level among the organs studied. While ABCC13 was expressed in the bone marrow, its expression in peripheral blood leukocytes of adult humans was much lower and no detectable levels were observed in differentiated hematopoietic cells. The expression of ABCC13 in K562 cells decreased during cell differentiation induced by TPA. These results suggest that the expression of human ABCC13 is related with hematopoiesis.