Tomoko Hiroki, Ph.D.
1997, Ph.D., Tokyo Medical and Dental University (Japan)
Research Interests
Characterization of locus control regions (LCR) in liver-specific genes.
Current Research
Vitamin D-binding protein (DBP)/Gc-globulin is a multifunctional serum glycoprotein, the major transporter of vitamin D sterols and one of the extracellular actin scavengers in serum. DBP is the oldest and most divergent member of its multigene family that includes albumin,
a-fetoprotein, and a-albumin/afamin. All four genes are linked on human chromosome 4q11-q13 and are expressed in the liver with overlapping developmental patterns. This linkage and common hepatic expression suggested that the four genes might share regulatory element(s) such as a locus control region (LCR). However, we recently found that the DBP gene is separated from the other genes by at least 1.5 Mb (Genome Res. 9:581,1999). This substantial separation suggested that DBP regulatory determinants were more likely to be dedicated to the DBP locus. We are now in the process of identifying and functionally characterizing remote regulatory elements that may serve as a Locus Control Region for the DBP gene. These studies make extensive use of hepatic cell lines and transgenic mouse models as well as in vitro DNA-protein assays.
Last Updated: Thu, May 17, 2001