Biology as Poetry: Cell Biology

Bacteriophage Ecology Group

Cell-to-Cell Communication

Ligands or direct contact (together, signal reception), receptors, signal transduction, and response together represent the key steps of this process.

Cell-to-cell communication is the means by which especially the cells within multicellular organisms coordinate their activity. The process begins with the reception of a signal, either a small molecule (typically a ligand) or instead this signal is the product of direct contact between cells (collectively, chemical signals). In either case, a specific receptor protein will exist in association with at least one of the cells involved. This receptor can be located on the surface of the cell or, instead (and less commonly), within its interior.

Reception of a signal initiates a series of biochemical events, collectively termed signal transduction or signal transduction pathways. This process carries the fact that a signal has been received towards its ultimate target within the cell and, typically, also greatly amplifies the signal. Lastly, the cell that received the signal then responds in some manner physiologically.

What signals a cell can respond to along with how it responds is dependent on what proteins are present within that cell. These proteins first will consist of receptors for the signal, with these receptors differing in terms of both their affinity for specific signals and there specificity for different signals. Cells will then differ in terms of how the signal is transduced, which again will be a function of what proteins are present within a cell. Lastly, cells can differ in terms of how they respond to the presence of a signal, with once again that response dependent on what proteins are present within a cell.

Development of multicellular organisms, that is, the formation especially of their anatomy, is hugely dependent on cell-to-cell signalling as also is the every day functioning of multicellular organisms, that is, their physiology. To understand how multicellular organisms function therefore is highly dependent on an appreciation of the concepts of cell-to-cell signaling.

While much of cell-to-cell signalling considers signals between cells making up the same organism, cell-to-cell signalling can also occur between cells that are not parts of the same organism or even the same species. Indeed, much of the way that free-living, unicellular organisms interact is via variations on the idea of cell-to-cell signaling.

See below for a list of terms associated with cell-to-cell communication:

Cell-to-cell communicationChemical signalingCyclic AMPG protein-linked receptorHormoneIon channel receptorLocal regulationParacrine signalingProtein kinaseReceptor proteinSecond messengerSignal receptionSignal transductionSignal transduction pathwayTyrosine kinase receptor
