PHGY 502 Lecture 12: Steroid Hormone receptors Part 2

• School: McGill University
• Department: Physiology
• Course: PHGY 502
• Professor: Simon Rousseau

Document Summary

Steroid hormones enter the cell by diffusion and bind to specific receptors. Receptors undergo a conformational change promotes heat shock protein dissociation, exposes the dbd & nls & dimerization domains and allows receptors to interact with other proteins. Receptors translocate to the nucleus and bind to hres as a dimer. The nearby promoter is activated and mrna transcription is initiated. Non-genomic steroid actions can be mediated through specific membrane receptors: to really study the effect of hormones on body physiology, mutations and their effects have to be studied. Germline vs. somatic mutations: germline mutation-hereditary mutation- passed from parents to the offspring, somatic mutation- occurs during the course of ones lifetime-may not necessarily be transmitted-unless it occurs in the gametes- e. g cancer mutation. Loss-of-function vs. gain-of-function: another basic concept, loss of function mutation- causes loss of function of protein after mutation, gain of function mutation- after mutation, protein will develop a new function that was different from its original function.