Transcriptional control of vitamin D‐regulated proteins

Abstract

Vitamin D is a physiological regulator of gene transcription associated with control of a broad spectrum of biological processes that include but is not restricted to growth, differentiation and calcium‐mediated homeostatic control. Transcriptional regulation is mediated by sequence‐specific interactions of a 1,25(OH)₂D₃‐vitamin D receptor‐accessory factor complex with vitamin D responsive elements (VDRE) residing in the promoters of hormone responsive genes. Functioning primarily as a transcription enhancer, activity at the VDRE is controlled by diverse and integrated cellular signalling pathways acting synergistically and/or antagonistically with a series of basal regulatory elements and other hormone regulated sequences that are components of modularly organized vitamin D‐responsive gene promoters. Molecular mechanisms that integrate the activities at promoter elements contributing to vitamin D‐related transcriptional control include overlapping transcription factor binding domains within regulatory elements and cooperative activities at independent regulatory sequences that determine the level of vitamin D responsiveness.