Gap Junctions: The complex bridge of the body
Gap junctions are a crucial component of cell to cell communication that connects cells and can transport a multitude of products. They can be found in all different types of body cells and assist with a variety of functions
Gap junctions have been found to be present in a variety of bone cells (Doty, 1981). Gap junctions, as intercellular bridges, connected adjacent bone cells and suggest they help in the control/coordination of bone cell activity. In most cells, gap junctions connect the cytoplasm of two cells and can transfer hydrophilic molecules. However, if an immune system response surfaces, rat cells can shut off these gap junctions in order to minimize the spread of a foreign substance (Fraser, 1987).
Gap junctions are even used in cells related to hormone distribution. Thyroid cells were found to reconstruct gap junctions in response to the hormone TSH. However, when the protein Kinase-C was activated, the functional activity of the gap junctions reacted negatively (Munari-Silem, 2009). Showing how different aspects of cell communication can intertwine, gap junctions can be affected by hormones. In fact, gap junctions can have different selectivity because the connexins subunits that form gap junctions can be mixed and matched, leading to a whole realm of complexity on what passes through the junctions (Kumar, 1996).
(Kumar,1996) Model of a pore in a gap junction. The pore is constructed by the different connexin sub units.
Sources
Doty, Stephen B. “Morphological Evidence of Gap Junctions between Bone Cells.” Calcified Tissue International 33.1 (1981): 509-12.
Fraser, S., C. Green, H. Bode, and N. Gilula. “Selective Disruption of Gap Junctional Communication Interferes with a Patterning Process in Hydra.” Science 237.4810 (1987): 49-55.
Munari-Silem, Yvonne, Christine Audebet, and Bernard Rousset. “Hormonal Control of Cell to Cell Communication: Regulation by Thyrotropin of the Gap Junction-Mediated Dye Transfer between Thyroid Cells.” Endocrinology 128.6 (1991): 3299-309.
Kumar, Nalin M., and Norton B. Gilula. “The Gap Junction Communication Channel.” Cell84.3 (1996): 381-88.
