Classes
There are three classes of SMAD:
- The receptor-regulated Smads (R-SMAD) which include SMAD1, SMAD2, SMAD3, SMAD5 and SMAD8/9
- The common-mediator Smad (co-SMAD) which includes only SMAD4, which interacts with R-SMADs to participate in signaling
- The antagonistic or inhibitory Smads (I-SMAD) which include SMAD6 and SMAD7, which block the activation of R-SMADs and Co-SMADs.
Read more about this topic: SMAD (protein)
Famous quotes containing the word classes:
“The difference between people isn’t in their class, but in themselves. Only from the middle classes one gets ideas, and from the common people—life itself, warmth. You feel their hates and loves.”
—D.H. (David Herbert)
“What’s the greatest enemy of Christianity to-day? Frozen meat. In the past only members of the upper classes were thoroughly sceptical, despairing, negative. Why? Among other reasons, because they were the only people who could afford to eat too much meat. Now there’s cheap Canterbury lamb and Argentine chilled beef. Even the poor can afford to poison themselves into complete scepticism and despair.”
—Aldous Huxley (1894–1963)
“Classes struggle, some classes triumph, others are eliminated. Such is history; such is the history of civilization for thousands of years.”
—Mao Zedong (1893–1976)