Molecular mechanisms of action of steroid/thyroid receptor superfamily members.

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 STEROID RECEPTOR SUPERFAMILY . . . . . . . . . . . . . . ... . . ... . . . . . 453 PROTEIN-DNA INTERACTIONS . . . . . . . . . . . . . . . . .. . . .. . . . . . . . . . 455 ROLE OF RECEPTOR IN GENE ACTIVATION AND SILENCING ......... 459 Gene Activation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 Gene Silencing . . .. . . .. . ... . . . . . . . . . . . . .... . . . . . ...... . . 462 SYNERGISM BETWEEN DIFFERENT CIS-ACTING ELEMENTS 465 ROLE OF LIGAND IN RECEPTOR TRANSFORMATION AND ACTIVATION . 466 Role of Ligand .... . ... . .. . .... . ..... . . ... . .. . . ........ . 466 Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471 FACTORS INFLUENCING RECEPTOR ACTIVITY . . . . . . . . . . . . . . . . . . . . 473 Phosphorylation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 Ligand-Independent Activation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475 Nuclear Transcription Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476 CHROMATIN STRUCTURE AND RECEPTOR ACTION . . . . . . . . . . . . . . . . 479 SUMMARY AND PERSPECTIVES 480