Regulation of activin's access to the cell: why is mother nature such a control freak?

Bioessays. 2000 Aug;22(8):689-96. doi: 10.1002/1521-1878(200008)22:8<689::AID-BIES2>3.0.CO;2-5.


Activin A is a pluripotent growth factor with important roles in development, erythropoiesis and the local regulation of many tissues. At the post-translational level, the amount of activin A produced by cells may be modulated through the diversion of activin A subunits into the formation of inhibin or other activins containing heterodimeric forms. Once assembled, activin interacts with various low- and high-affinity binding proteins, such as follistatin and alpha(2)-macroglobulin, that have consequences for receptor availability. In common with other TGFbeta family members, activin signals through pairs of type I and II receptor kinases and the Smad intracellular signalling cascade. Other checkpoints have been identified such as the recently identified pseudoreceptor, BAMBI. These emerging findings point to a tightly coordinated regulation of the exposure of a cell or tissue to activin, consistent with the low amounts of this potent factor that are necessary to modulate cellular responses.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Activin Receptors
  • Activins
  • Animals
  • Carrier Proteins / metabolism
  • Growth Substances / chemistry
  • Growth Substances / metabolism
  • Humans
  • Inhibins / chemistry
  • Inhibins / metabolism*
  • Models, Biological
  • Protein Structure, Quaternary
  • Receptors, Growth Factor / metabolism
  • Signal Transduction


  • Carrier Proteins
  • Growth Substances
  • Receptors, Growth Factor
  • Activins
  • Inhibins
  • Activin Receptors