The Cell-to-Cell Membrane Channel
I shall deal with a channel that spans two cell membranes. This channel was a solution to an ancient evolutionary problem: how to interconnect the cyberneting loops of information of different cells and to do so without mixing the information sources. The seeds for this problem were sown by evolution herself as she grew, during the first one and a half billion years: a hydrophobic membrane for the cells, a barrier to keep the hard-won informational molecules from drifting apart and to keep nonsense molecules from drifting in. The barrier was instrumental in the selection of cybernetically apt units in an aqueous environment and was absolutely necessary for Darwinian evolution of cells. But, over the next two billion years, the organismic times, it became an obstacle to multicellular organization. The problem was then how to get signal molecules across the hydrophobic barrier to interconnect the units without abolishing its primitive insulating function.
KeywordsCell Junction Rous Sarcoma Virus Nonpermissive Temperature Junctional Membrane Protein Kinase Type
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