Activin and inhibin
Activin and inhibin are two closely related protein complexes that have almost directly opposite biological effects. Identified in 1986,activin enhances FSH biosynthesis and secretion, and participates in the regulation of the menstrual cycle. Many other functions have been found to be exerted by activin, including roles in cell proliferation, differentiation, apoptosis,metabolism, homeostasis, immune response, wound repair, and endocrine function. Conversely inhibin downregulates FSH synthesis and inhibits FSH secretion. The existence of inhibin was hypothesized as early as 1916; however, it was not demonstrated to exist until Neena Schwartz and Cornelia Channing's work in the mid 1970s, after which both proteins were molecularly characterized ten years later.
Activin is a dimer composed of two identical or very similar beta subunits. Inhibin is also a dimer wherein the first component is a beta subunit similar or identical to the beta subunit in activin. However, in contrast to activin, the second component of the inhibin dimer is a more distantly-related alpha subunit. Activin, inhibin and a number of other structurally related proteins such as anti-Müllerian hormone, bone morphogenetic protein, and growth differentiation factor belong to the TGF-β protein superfamily.
Podcasts:
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by Anna Banana
For Derek
by: Anna BananaDerek Lorenzo,
Heard your song, I'm touched.
Though others may find
You a bit over-mush.
Derek Lorenzo,
You're sweet it seems
In English class, we used to work as a team.
Derek Lorenzo,
You're sweet and you want a shot.
Derek Lorenzo,
You want to eat lunch and you like me a lot.
CHORUS:
(well....)
Derek, forget it.
Don't like you that much.
You dance like a monkey,
And I don't think that's hot.
Derek, forget it, already.
You don't have a chance.
Not once, not twice, not thrice. It's more like never.
I'm not your fried banana, Derek.
But I am still hot.
verse2:
Derek, forget it.
Did you hear what I said?
We'll never be together,
It's all in your head.
Derek, forget it.
Stop saying my name,
My feelings stay the same --
I'm not your dame.
Go ride a train, or fly a plane
eat your grain in the falling rain.
This thing has to end
We don't blend
You can still be a friend.
Thank you. The end.
repeat chorus:
Derek, forget it.
I don't like you that much.
You dance like a monkey,
And I don't think that's hot.
Derek, forget it, already.
You don't have a chance.
Not once, not twice, not thrice. It's more like never.
I'm not your fried banana, Derek.