How is different signal transduction from information theory?

They look different.

“Signal transduction occurs when an extracellular signaling[1] molecule activates a specific receptor located on the cell surface or inside the cell. In turn, this receptor triggers a biochemical chain of events inside the cell, creating a response.[2] Depending on the cell, the response alters the cell’s metabolism, shape, gene expression, or ability to divide.[3] The signal can be amplified at any step. Thus, one signaling molecule can cause many responses.[4]

Signal transduction involves the binding of extracellular signalling molecules and ligands to cell-surface receptors that trigger events inside the cell. The combination of messenger with receptor causes a change in the conformation of the receptor, known as receptor activation. This activation is always the initial step (the cause) leading to the cell’s ultimate responses (effect) to the messenger. Despite the myriad of these ultimate responses, they are all directly due to changes in particular cell proteins. Intracellular signaling cascades can be started through cell-substratum interactions; examples are the integrin that binds ligands in the extracellular matrix and steroids.[13]

[wiki source]

 

It seems that signal transduction involves:

  • messenger molecule
  • receptor molecule
  • the messenger reacts with the receptor, which changes conformation (receptor activation)
  • receptor activation triggers other chemical reactions

Let’s condense further:

  • molecule M (messenger) binds to molecule R (receptor)
  • the complex MR changes shape (a spatial notion, in a generalized sense)
  • which triggers other reactions between (the new) R with other neighboring molecules.

It is interesting for me because that is how distributed GLC works:

  • the actor M reacts with the actor R
  • after interaction both molecules may change, the one which belongs to the actor M and the one which belongs to the actor R,
  • but also the actors adjacencies may change as well, due to the reductions involving the reaction between M and R (this corresponds to the receptor activation)
  • which triggers other interactions between GLC actors.

 

Information theory, on the other side, concerns a sender, a channel and a receiver. The sender sends messages through the channel to the receiver.

Completely different frames.

One may, of course, partially ignore the mechanism (signal transduction) and look instead at the environment as a sender, to the cell as a receiver and to the cell’s membrane as a channel (just an example).

But sender, channel and receiver look (to me) as mind constructs which are useful for the human trying to make a sense of what is happening, from outside. What is happening though,  is signal transduction.

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5 thoughts on “How is different signal transduction from information theory?”

  1. Interesting thoughts!!
    In an entirely different framework, my intuition would be to represent M, R, and MR as three channels. To do this, one would want to figure out the relevant information measures for such molecules. But molecules aren’t transmitting typical sequences- what are they transmitting?

    1. Thanks!
      Yes, one may artificially introduce channels and gates (like in “DNA gates”) but the point is exactly this: they don’t transmit anything. The transmission-channel-sender-receiver-… thing comes from the IT, which has historical roots in the transmission problem (telegraph, telephone, radio, wars and secrecy).

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