Biochemistry of cell communication; message molecules (Introduction)

by David Turell , Saturday, February 17, 2018, 18:22 (2257 days ago) @ David Turell

A deep study as to how they communicate signals, and iti s not simple:

https://www.sciencedaily.com/releases/2018/02/180216150338.htm

"Cells carry out their conversations using specialized communication molecules called ligands, which interact with corresponding molecular antennae called receptors. When a cell uses the Notch pathway to communicate instructions to its neighbors -- telling them to divide, for example, or to differentiate into a different kind of cell -- the cell sending the message will produce certain Notch ligands on its surface. These ligands then bind to Notch receptors embedded in the surface of nearby cells, triggering the receptors to release gene-modifying molecules called transcription factors into the interior of their cell. The transcription factors travel to the cell's nucleus, where the cell's DNA is stored, and activate specific genes. The Notch system thus allows cells to receive signals from their neighbors and alter their gene expression accordingly.

"Ligands prompt the activation of transcription factors by modifying the structure of the receptors into which they dock. All ligands modify their receptors in a similar way and activate the same transcription factors in a receiving cell, and for that reason, scientists generally assumed that the receiving cell should not be able to reliably determine which ligand had activated it, and hence which message it had received.

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"So, the question is, as a cell, how do you differentiate between two ligands, both of which look like similar puffs of smoke in the distance?"

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"The team studied two chemically similar Notch ligands, dubbed Delta1 and Delta4. They discovered that despite the ligands' similarity the two activated the same receptor with strikingly different temporal patterns. Delta1 ligands activated clusters of receptors simultaneously, sending a sudden burst of transcription factors down to the nucleus all at once, like a smoke signal consisting of a few giant puffs. On the other hand, Delta4 ligands activated individual receptors in a sustained manner, sending a constant trickle of single transcription factors to the nucleus, like a steady stream of smoke.

"These two patterns are the key to encoding different instructions to the cell, the researchers say. In fact, this mechanism enabled the two ligands to communicate dramatically different messages. By analyzing chick embryos, the authors discovered that Delta1 activated abdominal muscle production, whereas Delta4 strongly inhibited this process in the same cells.

"Cells speak only a handful of different molecular languages but they have to work together to carry out an incredible diversity of tasks," says Elowitz. "We've generally assumed these languages are extremely simple, and cells can basically only grunt at each other. By watching cells in the process of communicating, we can see that these languages are more sophisticated and have a larger vocabulary than we ever thought. And this is probably just the tip of an iceberg for intercellular communication.'" (my bold)

Comment: We see here a system as complex as our brain's relationship to its s/s/c, in that information (immaterial) is transmitted by material timing actions by the molecules. Yet we can ask, are cells truly conscious in and of themselves? That consciousness fully pervades all levels of the universe is reasonable. And I believe God is universal consciousness.