Biochemistry of cell communication; message molecules (Introduction)

by David Turell , Monday, July 09, 2018, 21:18 (2111 days ago) @ dhw

A new study of how these molecules work to pick up signals:

https://www.sciencedaily.com/releases/2018/07/180709152701.htm

" INRS professor Nicolas Doucet and his research team contributed to the discovery of this new molecular switch, shedding new light on the role of receptor tyrosine kinases, a well-known protein family whose function is still being explored.

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"Receptor tyrosine kinases (RTKs) are a family of proteins that carry out many tasks required for organism growth and maintenance. They are found in every cell of the human body and broadly act on processes ranging from cell organization to nutrient management. Despite their distinct roles, they conserve a high degree of structural similarity at the molecular level, suggesting that each component of their three-dimensional structure plays an important role in their biological function. However, only recently has technology become sufficiently precise to peer into key molecular interactions of RTKs at the atomic level.

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"One of the main difficulties Prof. Doucet's research team had to face was the need to clearly demonstrate that NCK and EPHA4 could recognize each other at the molecular level. If not, phosphorylation would be off the table.

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"RTK receptors embedded in the cell membrane stick their 'sensory receivers' outside the cell and extend their enzymatic machinery inside the cell. Part of their equipment is a kinase, an enzyme that activates other proteins by adding a phosphate group to specific amino acids on their surface. This process is known as phosphorylation.

"To activate a cellular signaling pathway, RTKs pair up as soon as a receiver picks up a signal. Linking together involves reciprocal action, with each partner accepting a phosphate group from the other. All partners then line up in such a way that they can interact with a new molecule, thus initiating the required cellular function."

Comment: These are organic molecules working from their innate abilities to change shape and/or electrical attraction fields with ions charges. No brain or DNA instructions involved. The molecules are designed and chosen to fill a specific repetitive role without an mental thought involved