Hi, Paula, I admit I didn't understand a lot of it, either. I'm not very scientifically minded. Hopefully if someone or someone's child has the condition they'll understand it better. (smile) Cindy --- Paula and James Muysenberg <outofsightlife@xxxxxxxxxxx> wrote: > Hi, Cindy, > > I couldn't follow all this, but it is > fascinating. I recently read and > validated a book Sarah submitted, called Darwin's > Black Box, by Michael > Behe. Reading all that technical description about > enzymes and the visual > process seemed like another page out of Behe's book. > It's funny how, since I > read the book, similar material seems to keep > popping up. > > Thanks for forwarding this article. > > Paula Muysenberg > > ----- Original Message ----- > From: "Cindy" <popularplace@xxxxxxxxx> > To: <bksvol-discuss@xxxxxxxxxxxxx> > Sent: Friday, August 12, 2005 1:27 AM > Subject: [bksvol-discuss] OT: UCLA identifies enzyme > linked to childhood > blindness > > > > I heard an quick item on the car radio, and when I > > came home I looked it up. This may be of some > interest > > to some of you. > > > > Cindy > > > > UCLA researchers identify key enzyme linked to > > childhood blindness > > > > Findings could lead to gene therapy cure > > In findings that could lead to curing some forms > of > > congenital blindness through gene therapy, > researchers > > at UCLA have discovered that RPE65, a gene missing > in > > infants born with the blinding disease Leber > > congenital amaurosis, is also a key enzyme in the > > visual cycle. The identity of this enzyme has long > > been a mystery to scientists. > > > > The study, "Rpe65 is the Retinoid Isomerase in > Bovine > > Retinal Pigment Epithelium," is published in the > Aug. > > 12 issue of Cell magazine. > > > > "We were amazed when we discovered the function > for > > Rpe65 -- and that Rpe65 is the retinoid isomerase. > It > > is a protein that all of us had known about for > > years," said Dr. Gabriel Travis, professor of > > ophthalmology and biological chemistry at UCLA's > Jules > > Stein Eye Institute and one of the researchers. > "It's > > like searching the world for a treasure, then > > discovering it in your own back yard." > > > > Leber congenital amaurosis is an inherited disease > > that is believed to cause up to 20 percent of all > > cases of childhood blindness. It is caused by > > mutations in several different genes including > RPE65. > > An important characteristic of this disease is > that > > the light sensitive rod and cone cells remain > intact > > in the retinas of Leber patients for a long time. > > > > "This suggests that replacement of RPE65 by gene > > therapy should correct the blindness in these > > children, as was observed in mice and dogs with > RPE65 > > mutations," Travis said. "This is a major > breakthrough > > in understanding the visual cycle. It has > > ramifications for several inherited blinding > diseases > > caused by mutations in visual cycle genes." > > > > The newly identified isomerase enzyme plays a > crucial > > role in the regeneration of rhodopsin visual > pigment > > in the retina after light exposure. Rhodopsin > contains > > a light absorbing molecule called 11 cis > > retinaldehyde, related to vitamin A, which is > > converted upon light absorption to all trans > > retinaldehyde in a process called photo bleaching. > > This conversion is the first step in visual > > perception. > > > > Photo bleaching leaves the rhodopsin insensitive > to > > light until the all trans retinaldehyde is > converted, > > or "isomerized," back into 11 cis retinaldehyde, > which > > completes the visual cycle. Scientists have for > two > > decades been attempting to identify the retinoid > > isomerase enzyme that catalyzes this regeneration > of > > 11 cis retinaldehyde. Scientists have also been > > stumped by the function of the Rpe65 protein > > > > Working with Travis at the Jules Stein Eye > Institute, > > Dr. Minghao Jin, visiting assistant researcher in > > ophthalmology, performed an expression screen in > > cultured human cells, looking for a gene that > caused > > these cells to convert vitamin A into 11 cis > retinol. > > > > The researchers are now studying the effects on > > retinoid isomerase activity of specific disease > > causing mutations in the RPE65 gene, which should > > provide more data on the cause of Leber congenital > > amaurosis and on how the Rpe65 protein works. The > > researchers are also examining the function of > other > > proteins that work closely with Rpe65. Mutations > in > > the genes for these interacting proteins are > linked to > > other forms of human blindness. > > > > "These results settle the long standing mystery > about > > the identity of the retinoid isomerase," Travis > said. > > "Scientists have been searching for this enzyme > for > > almost 20 years. Our results also explain why > finding > > this enzyme has been so difficult, until now." > > > > Other researchers on this project besides Travis > and > > Jin are Hui Sun, assistant professor of physiology > at > > UCLA, and Songhua Li and Walid Moghrabi, staff > > research associates at the Jules Stein Eye > Institute. > > > > ### > > > > The National Eye Institute, the Foundation for > > Fighting Blindness, and Research to Prevent > Blindness > > funded the study. > > > > > > > > > > __________________________________ > > Yahoo! Mail > > Stay connected, organized, and protected. Take the > tour: > > http://tour.mail.yahoo.com/mailtour.html > > > > > > > > > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com