Experimental Regimen: Obliterating the androgen machinery
Ever wonder why you still have dark body hair, after being on estrogen for two years? Maybe some patches of hair, perhaps on your arms, have lightened up, and you still have brown chest hairs? Why do you have to get laser or electrolysis in the first place?
Life of an Androgen Receptor
Why's masculine body hair dark?
Androgen receptors (ARs) chill in the cytosol, outside the nucleus of a cell, feeling single and lonely. Testosterone swims by outside, doing laps until a hexagonal gate in the cell membrane opens, pulling it in down a slippery slide of electromagnetic charge. The testosterone swims in the cytosol for a while, until it activates an AR. Once testosterone, like a key, fits inside the AR's lock, the ARs twist open to expose a foot. Next, a rowboat comes up, grabs ahold of the two ARs' feet and paddles down to the nucleus, where it's shuttled inside. That's where all the cool DNA hangs out. It's in the VIP room, baby!
Next to the genes for facial and male-pattern body hair (HHA6 and HHA7, I think, too lazy to look it up), there's a little palindrome of DNA (AGAACA, upside-down and reversed on the other strand spells the same) called an Androgen Response Element! (ARE.) Each AR has a single arm on it, which latches onto only that palindrome. Behold! With both their arms, they clamp down on the ARE and snap tight. The AR's other head is a handle for RNA polymerase, which kicks off making the gene south of the ARE into a protein. The AR flips a switch, the HHA6 and HHA7 keratin is made, and your hair is black.
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