AquaporinBy Ryan Osgood and Mackenzie Blinn

What they are

• Aquaporin is a protein embedded in the cell membrane in order to regulate the flow of water

• Water needs to move in and out of a cell, and this is facilitated by aquaporins (water channels)

• The presence of these water channels increases the permeability to water of the cell membrane

• These channels are allocated in all kingdoms of life including bacteria, plants, and mammals

• 13 in mammals, 6 in kidney

• In plants- 4 families

Used for

• Industrial water treatment

• Regulates flow of water in organisms, particularly in the kidney.

Who discovered them• In 1992 Peter Agre at John

Hopkins University reported his unintentional discovery of aquaporin, he earned a Nobel Prize for his discovery in 2003 .

• In 2000 Stroud’s lab at UCSF succeeded in solving the first high resolution structure of an aquaporin by using x-ray crystallography

Primary Structure

• Used for water reabsorption

• Found in kidney

• We can see its primary structure because of the amino acid linear sequence

• Simple proteins- AQP monomer has 6x helical domains

Secondary Structure

• 6 trans membrane helices in a RH Bundle- it forms a tetrameter

• Early evolutionary event

• Used for water reabsorption in response to ADH (a hormone)

• We can see its secondary structure because of the alpha-helices

Tertiary Structure

• Found in kidney and medullary collecting duct

• Used for water reabsorption and glycerol permeability

• We can see its tertiary because of the tightness of the helixes folded in one compact globule.

Quaternary Structure

• Used for water reabsorption

• Found in kidney

More on that…

• Some membranes are more permeable than others. RBC’s, kidney tubules

• AQP 1 was reported in 1992.

Diseases

• Several diseases such as congenital cataracts and nephrogenic diabetes insipidus are relate to mutations in aquaporins, also fluid transport, brain swelling, strokes, meningities, multiple sclerosis.

• A small number of people are found with a deficiency of aquaporins and they generally seem healthy, but they have a defect in the ability to concentrate solutes in urine and to conserve water when deprived of drinking water

Bibliography

• http://www.ks.uiuc.edu/Research/aquaporins/

• http://www.bionaid.us/research.htm

• http://www.aquaporins.org/disease.htm

• http://www.hopkinsmedicine.org/press/2003/october/031008a.htm

• http://en.wikipedia.org/wiki/Aquaporin