They found that the melanosomes without OCA2 produced much less current and much less melanin. In experiments where they made endolysosomes express OCA2, for example, they measured currents related to the passing of chloride ions.
About 1 in 40, people worldwide have type 2 oculocutaneous albinismwhich has symptoms of unsually light hair Albinism research skin coloration, vision problems, and reduced protection from sunlight-related skin or eye cancers. Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews.
They were able to turn to helpful colleagues. They also used endolysosomes to find that that the OCA2 mutation VI specifically affects the ion channel. A biology discovery More generally, the study is also significant for being the first to show that ion channels are important for melanosomes to function properly.
Anita Zimmerman, professor of medical science who works down the hall at Brown University, tipped them off that bullfrogs happen to have especially large melanosomes in their retinas. That mutation decreased the chloride ion current by 85 percent compared to normal versions of the protein.
The ion channel is like a gate that lets electrically charged chloride molecules flow into and out of the melanosome. Patch clamp experiments with those large melanosomes confirmed the role of the VI mutation in the failure of chloride ion channels. First, they compared chloride currents in normal melanosomes and ones in which they used interference RNA a method of blocking gene expression targeted to prevent OCA2 production.
The discovery could inspire new ideas for treating albinism, said Elena Oancea, assistant professor of medical science and senior author of the paper published in the journal eLife.
For more information, call Into the melanosome But to truly understand the role of OCA2 and the VI mutation in albinism, the researchers needed to look directly at melanosomes. Co-author Michael Marks at the University of Pennsylvania introduced them to a line of mutant mouse skin cells that had unusually large melanosomes.
In another experiment Oancea and Bellono showed that expression of normal OCA2 in the endolysosomes, which are acidic organelles, reduced acidity to above 6 on the pH scale, which is required in a melanosome for the protein tyrosinase to trigger melanin production.
That provided their first key evidence that the protein was associated with an ion channel.
In the new research a team led by Brown University biologists Nicholas Bellono and Elena Oancea shows that the protein is necessary for the proper functioning of an ion channel on the melanosome organelle, the little structure in a cell where melanin is made and stored.
Another potential treatment suggested by the research could be to alter melanosome acidity to make up for the lack of the protein.A team led by Brown University biologists has discovered the way in which a specific genetic mutation appears to lead to the lack of melanin production underlying a form of.
Albinism News and Research RSS. Albinism is a condition marked by reduced production of melanin, the pigment that provides color to the hair, skin, and eyes of.
Medical research for Albinism including cure research, prevention research, diagnostic research, and basic research. Information about current research studies and opportunities on many aspects and types of albinism. Recent research has used analysis of DNA, the chemical that encodes genetic information, to arrive at a more precise classification system for albinism.
Seven forms of oculocutaneous albinism are now recognized – OCA1, OCA2, OCA3, OCA4, OCA5, OCA6 and OCA7. May 24, · Albinism is a group of inherited disorders that results in little or no production of the pigment melanin, which determines the color of the skin, hair and eyes.
Melanin also plays a role in the development of certain optical nerves, so all forms of albinism cause problems with the development and function of the eyes.Download