This video is part of playlist examining the diverse biological factors which influence the development of chromosomal, gonadal, somatic, and brain gender. The playlist: is located on my youtube channel drjahn41
How do steroid hormones like the estrogen i’ll discuss in this video how do they affect cells well there’s a simple version of the story unlike most hormones which bind to a receptor on the cell membrane and activate second messengers these steroid hormones because steroids like estrogen or nonpolar can pass through the cell membrane where they bind to receptors
Inside the cell the receptors and the hormones bound to them then go to the nucleus where they bind to dna and then change which genes are turned on or off the situation is a bit more complicated there are two estrogen receptors one encoded by chromosome 6 making a protein of 595 amino acids and one encoded by chromosome 14 which can encode proteins which can vary
In size 530 amino acids 495 or 513 depending on how it’s spliced estrogen receptor alpha and beta are similar the portions which bind dna to turn on genes are extremely similar maybe 95 identical or more whereas those which are binding the ligand like the estrogen are only about 55 identical so they form dimers and they can form homodimers where two estrogen
Receptor alphas bind together or a homodimer where two estrogen receptor beta binds together where they can form a heterodimer where it’s one of each typically these two receptors have comparable effects when estrogen binds them but there are examples known where estrogen binding to the beta receptor has an opposite reaction as it’s binding to an alpha receptor
Here you can see cells of the ovary involved in reproductive function these cells have estrogen receptors but which estrogen receptors they express can vary the thetal cells can express the estrogen receptor alpha and the granulosa cells can express the estrogen receptor beta so even though they’re responding to estrogen with estrogen receptors they can vary in
Which they express in the prostate gland depicted here the epithelium is expressing the estrogen receptor beta but the deeper stroma is expressing the estrogen receptor alpha there are other examples of this so that the breast tissue the uterus and the liver would mainly express the alpha receptor while the lung colon and immune system would primarily express
The beta receptor both of these receptors are typically expressed to comparable levels in the cardiovascular system the nervous system including parts of the brain and adipose
Transcribed from video
ESTROGEN RECEPTOR FUNCTION the more complicated version 1 By Walter Jahn