Wednesday, March 16, 2011

Aquaporins; The Cellular Highway for Water Molecules

  1. Preston, G. M., P. Piazza-Carroll, W. B. Guggino, and P. Agre. (1992). Appearance of water channels in Xenopus oocytes expressing red cell CHIP28 water channel. Science, 256, 385–387 - Although, we know water can travel through cell membranes, specialized proteins are an important part of facilitating such a constant movement. These 'water channels' now called aquaporins exist across such cellular membranes, or lipid bilayer membranes, and allow the rapid and selective transport of water into or out of the cell. Furthermore, there seems to be a sort of regulation of these water channels to increase or decrease water permeability.

  2. Agre, P., M. Bonhivers, and M. J. Borgnia. (1998).The aquaporins, blueprints for cellular plumbing systems. Journal of Biolgical Chemistry, 273, 14659–14662 - Since the original discovery of Aquaporins in 1992, several units, including the kidneys and plant roots, which require a higher than average flux of water into and out of cells have been researched. The requirement for a high flow of water is met by the specific function of aquaporins. Even the lungs in mammals have special arrangements of aquaporins to ensure humidification of the airways. Much is still being learned about the physiological role and structure of aquaporins.

  3. Borgnia, M., S. Nielsen, A. Engel, and P. Agre. (1999). Cellular and molecular biology of the aquaporin water channels. Annual Review of Biochemistry, 68, 425–458 - It has been found that many aquaporin variations exist. Those common in humans are AQP1, AQP2, and nine others. The permeability of water through many of these aquaporin water channels has been estimated to be an amazing 10^9 molecules of water per second! Furthermore, some variations of aquaporins, called aquaglyceroporins, act as a channel for glycerol and small solutes in addition to water. And, though much progress has been made in characterizing the structure of aquaporins, much is still unclear about these variations. This paper goes on to review the aquaporins found in plants, amphibians, insects, and some bacteria.

  4. Kumar, M., M. Grzelakowski, J. Zilles, M. Clark, and W. Meier. (2007). Highly permeable polymeric membranes based on the incorporation of the functional water channel protein Aquaporin Z. Proceedings of the National Academy of Sciences of the United States of America, 104:52, 20719-20724 - Some exciting work is being done in an effort to assess how aquaporins might have application in drug delivery or water purification. By placing AqpZ (an aquaporin found from E. coli) in a synthetic polymer membrane, scientists found that water permeability was observed at up to 800 times that of the pure polymer.

2 comments:

  1. Thanks for sharing an interesting article on Aquaporin. It feels great to learn new things and enhance one's knowledge. Keep sharing such interesting blogs.

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