René St-Arnaud¹, G. Antonio Candeliere¹, and Shoukat Dedhar²

¹Genetics Unit, Shriners Hospital, and Departments of Surgery and Human Genetics, McGill University, Montréal (Québec) Canada H3G1A6

²Division of Cancer Research and Department of Medical Biophysics, University of Toronto, Reichmann Research Building, Sunnybrook Health Science Centre, Toronto (Ontario) Canada M4N 3M5

Received 07/05/96; Accepted 07/12/96; On-line 08/01/96

Vitamin D exerts its genomic effects following binding to a specific receptor which is a member of the steroid hormone receptor superfamily. The vitamin D receptor (VDR) forms heterodimers with retinoid X receptors (RXRs) and the dimer then interacts with its cognate binding site, termed vitamin D response element (VDRE), to affect the transcription of target genes.

Recent studies have identified novel sequence motifs for VDREs as well as novel protein-protein interactions involving the VDR. These will be reviewed with particular emphasis on the complex VDRE from the c-fos proto-oncogene promoter region and the inhibition of the vitamin D signal transduction pathway by the multifunctional protein, calreticulin.

Thus research on the control of gene transcription by vitamin D reveals examples of molecular interplay between transcriptional regulatory pathways and provides new insight into the molecular mechanism of action of vitamin D.