Featured Research

from universities, journals, and other organizations

Mammalian Clock Protein Responds Directly To Light

Date:
July 1, 2008
Source:
Public Library of Science
Summary:
We know that light effects the growth and development of plants, but what about humans and animals? New research explores this question by examining cryptochromes in flies, mice, and humans. In plants, cryptochromes are related to functions such as growth and development. Cryptochromes are present in humans and animals as well and regulate the mechanisms of the circadian clock. But how they work in humans and animals remains a mystery.

Using biophysical techniques to monitor cryptochrome blue light photoreceptors in living cells as they undergo a chemical redox reaction in response to light, researchers show that cryptochromes share similar properties in organisms ranging from plants to higher animals and humans.
Credit: Ahmad et al.

We all know that light effects the growth and development of plants, but what effect does light have on humans and animals? A new paper by Nathalie Hoang et al., published in PLoS Biology, explores this question by examining cryptochromes in flies, mice, and humans.

In plants, cryptochromes are photoreceptor proteins which absorb and process blue light for functions such as growth, seedling development, and leaf and stem expansion. Cryptochromes are present in humans and animals as well and have been proven to regulate the mechanisms of the circadian clock. But how they work in humans and animals is still somewhat of a mystery.

When plants are exposed to blue light, they experience a reduction in flavin pigments. This reduction activates the cryptochromes and thus allows for growth and seedling development. Hoang et al. sought to study the effect of blue light on fly, animal, and human cryptochromes by exposing them to blue light and measuring the change in the number of oxidized flavins. After a prolonged exposure to blue light, the authors found that the number of flavins did in fact decrease, as they do in plants.

While this research reveals a similarity in the responses of flies, mice, humans, and plants to blue light, the decrease in flavins affects circadian rhythms differently. The mouse cryptochromes, Mcry1 and Mcry2, interact with key parts of the circadian clock: mice with these cryptochromes missing exhibited a complete loss in circadian rhythm behaviors such as wheel-running. However, this change in behavior was independent of light exposure.

Although this paper by Hoang, et al, shows that cryptochromes in animals and humans do respond to light in a similar fashion to those in plants, the question as to how exactly light effects them is still open for further research. Although cryptochromes are mainly found in the retina of the eye, they are also present in many different tissues of the body that are close to the surface. This suggests that cryptochromes may have non-visual functions, and may also affect protein levels and behavior.


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hoang et al. Human and Drosophila Cryptochromes Are Light Activated by Flavin Photoreduction in Living Cells. PLoS Biology, 2008; 6 (7): e160 DOI: 10.1371/journal.pbio.0060160

Cite This Page:

Public Library of Science. "Mammalian Clock Protein Responds Directly To Light." ScienceDaily. ScienceDaily, 1 July 2008. <www.sciencedaily.com/releases/2008/06/080630200959.htm>.
Public Library of Science. (2008, July 1). Mammalian Clock Protein Responds Directly To Light. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2008/06/080630200959.htm
Public Library of Science. "Mammalian Clock Protein Responds Directly To Light." ScienceDaily. www.sciencedaily.com/releases/2008/06/080630200959.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Bear Cub Strolls Through Oregon Drug Store

Raw: Bear Cub Strolls Through Oregon Drug Store

AP (Oct. 22, 2014) Shoppers at an Oregon drug store were surprised by a bear cub scurrying down the aisles this past weekend. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Family Pleads for Pet Pig to Stay at Home

Family Pleads for Pet Pig to Stay at Home

AP (Oct. 22, 2014) The Johnson family lost their battle with the Chesterfield County, Virginia Planning Commission to allow Tucker, their pet pig, to stay in their home, but refuse to let the board keep Tucker away. (Oct. 22) Video provided by AP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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