Vitamin D3 Receptors: Structure and Function in Transcription

PERSPECTIVES AND SUMMARY 190 VITAMIN D3 HORMONE 191 Metabolism to the Active Form ......... . .... 191 Biologic Actions. ...... . ....... ......... . . . . . . ...... ..... ...... . . ... . . .. . . .... . . . . . ... 192 Transcriptional Mechanism of Action . . . . . . . . . . ....... . . . . .. . . . ...... . . 192 VITAMIN D3 RECEPTOR 193 Cellular Distribution. . 193 Biochemical Properties and Subcellular Distribution.. . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .... . . 194 Vitamin D3 Receptor Regulation.... . . . ........ . ..... . .... ........ . . . . .... .. . . . ...... 196 MOLECULAR BIOLOGY OF THE VITAMIN D3 RECEPTOR 198 Recombinant Cloning of the Vitamin D3 Receptor .... .... . ...... . . ..... .. . .. . ....... ...... 198 Steroid, Thyroid, and Retinoid Receptor Supeifamily 200 Structural Organization of the Nuclear Receptors ..... ....... . .. . . . .... . . . .. 200 Role of the Vitamin D3 Receptor in Transactivation . ........ . ...... . . . ..... . . ..... . . . . . .. 202 HUMAN SYNDROME OF HEREDITARY 1,25-DIHYDROXYVITAMIN D3 RESISTANCE 205 Vitamin DrResistant Fibroblast Model .... ......... . . ........ .. . . . . . . ...... 205 Genetic Lesions in the Vitamin D3 Receptor Chromosomal Locus . ....... . . ...... . . . .. 206 Functional Activity of Receptors Derived from Patient Genotypes 208 CONCLUSIONS 208