Featured Research

from universities, journals, and other organizations

Sugar Coupled To Protein Causes Kidneys To Save Water

Date:
October 13, 2003
Source:
Netherlands Organization For Scientific Research
Summary:
Several new mechanisms that are important for the production and transport of water channels to the cell surface of kidneys have been identified by a Dutch researcher. The water channels ensure that water in the body is reused. If these fail to work properly, you urinate too much and dehydrate.

Several new mechanisms that are important for the production and transport of water channels to the cell surface of kidneys have been identified by a Dutch researcher. The water channels ensure that water in the body is reused. If these fail to work properly, you urinate too much and dehydrate. The research was a collaborative project between the University Medical Centre Utrecht and the University Medical Centre Nijmegen.

Giel Hendriks discovered that the linking of sugars to the protein aquaporin-2 (AQP2) is necessary for the transport of water channels to the cell surfaces in the kidneys. If the protein is not linked to a sugar, it still forms functional water channels. However, these channels no longer end up at the cell surface where they need to do their work.

Kidneys extract water containing dissolved waste substances from the blood. Each day human kidneys produced about 180 litres of this so-called pro-urine. The excretion of all of this fluid would rapidly result in dehydration and eventual death. Therefore with the help of the water channels, the body returns about 99% of this water from the pro-urine to the kidney tissue. As a result of this a person only loses about 1.5 litres of urine per day.

The protein aquaporin-2 regulates a significant part of this water reuse. This protein forms water channels. These are transported from small storage vesicles to the cell surface, where they can collect the water and return it to the kidney tissue.

Mutations in AQP2 give rise to the disease nephrogenic diabetes insipidus (NDI). Patients with this disease lose 15 to 20 litres of urine per day. Knowing how AQP2 is transported to the cell surface and how it works there, is a prerequisite for developing a treatment for this disease.

In addition to the effect of sugars, Hendriks also studied the role of the small signalling protein ubiquitin in the functioning of AQP2. Ubiquitin ensures the breakdown of proteins and is important for quality control during the production of new proteins. Hendriks isolated AQP2 proteins to which a single ubiquitin was bound. Separating the proteins on the cell surface from those inside the cell revealed that only AQP2 with a single ubiquitin is located on the cell surface. The role of this coupling in the functioning of the protein will be investigated in a follow-up study by the Utrecht group.

Finally, the researchers isolated a new protein from a mouse kidney, AQP2-BP that directly binds to AQP2. Up until now no proteins capable of binding to AQP2 were known. By inserting both proteins in kidney cells, Hendriks discovered that AQP2-BP is important for the production of the useful protein AQP2.

###

The research was funded by the Netherlands Organisation for Scientific Research.


Story Source:

The above story is based on materials provided by Netherlands Organization For Scientific Research. Note: Materials may be edited for content and length.


Cite This Page:

Netherlands Organization For Scientific Research. "Sugar Coupled To Protein Causes Kidneys To Save Water." ScienceDaily. ScienceDaily, 13 October 2003. <www.sciencedaily.com/releases/2003/10/031013000841.htm>.
Netherlands Organization For Scientific Research. (2003, October 13). Sugar Coupled To Protein Causes Kidneys To Save Water. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2003/10/031013000841.htm
Netherlands Organization For Scientific Research. "Sugar Coupled To Protein Causes Kidneys To Save Water." ScienceDaily. www.sciencedaily.com/releases/2003/10/031013000841.htm (accessed April 24, 2014).

Share This



More Health & Medicine News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
Companies Ramp Up Wellness to Lower Health Costs

Companies Ramp Up Wellness to Lower Health Costs

AP (Apr. 24, 2014) That little voice telling you to exercise, get in shape and get healthy is probably coming from your boss. More companies are beefing up wellness programs to try and cut down their health care costs. (April 24) Video provided by AP
Powered by NewsLook.com
Blood From World's Oldest Woman Suggests Life Limit

Blood From World's Oldest Woman Suggests Life Limit

Newsy (Apr. 24, 2014) Scientists say for the extremely elderly, their stem cells might reach a state of exhaustion. This could limit one's life span. Video provided by Newsy
Powered by NewsLook.com
FDA Wants To Ban Sales Of E-Cigarettes To Minors

FDA Wants To Ban Sales Of E-Cigarettes To Minors

Newsy (Apr. 24, 2014) The Food and Drug Administration wants to crack down on the use of e-cigarettes, banning the sale of the product to minors. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins