It turns out that it is “ taste can be sensed '' with protein necessary to see things with eyes


It turns out that it is “ taste can be sensed '' with protein necessary to see things with eyes

A research team at the University of California, Santa Barbara, says a protein that functions as a visual receptorOpsinHas also functioned as a taste receptor. The team's findings suggest that humans may have new taste receptors.

Functions of Opsins in Drosophila Taste
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Subtle flavors | EurekAlert! Science News–sf040220.php

Below is a cross section of the human eyeball.irisThe light narrowed down byCrystalline lensThroughretinaHits. The photoreceptor cells in the retinaRhodopsinThere is a visual receptor called "", and this rhodopsin changes its structure when stimulated by light, and the change becomes information and is transmitted to nerves and processed by the brain, so that people can see things That is.

Rhodopsin says,OpsinAnd a protein calledRetinalIt is made up of a type of vitamin A called "Vitamin A." Until recently, opsin was said to respond only to light stimuli, but Professor Craig Montell of the University of California, Santa Barbara, Department of Biology, said in 2011 that “ Drosophila senses temperature changes with opsin ''AnnouncementDid.

Professor Montel and Nicole Leng, who has just completed his doctoral course, conducted an experiment to check the taste of the fly, thinking that the opsin molecule may also detect subtle chemical changes through the signal amplification process. .

Montelu and colleagues say that Drosophila is "sugar only"Aristolochic acidA small amount of sugar "was given to the two feeders. Then, Drosophila melanogaster ignored bitter food and ate preferentially sugar-only food.

Next, when the Drosophila melanogaster was rearranged so that it did not normally express opsin, flies lacking one of the three types of opsin could not detect a small amount of aristolochic acid, and the sugar-only feed It turned out that both of them and the food containing aristolochic acid were eating the same amount.

However, when mixing a large amount of aristolochic acid with sugar, he said that he also avoided flies with defects in opsin, says Professor Montell.TRPA1 channelBy activating the receptor, even a slight bitter taste is sensed, but a large amount of aristolochic acid may directly activate the TRPA1 channel even in a fly with an abnormal opsin, '' he speculated. If so, it would act as a protein to detect undetectable levels of aristolochic acid.

According to Professor Montell, aristolochic acid also binds to opsin, just like retinal binds to opsin to form rhodopsin. Opsin, which is chemically activated by aristolochic acid, performs a molecular chain reaction that amplifies a small signal, as rhodopsin responds to even a slight light stimulus.

From the results of this experiment, Prof. Montell speculates that the role of opsin may be its original role as a chemical sensor. Taste refers to "how to avoid chemicals that could be dangerous to you", and is one of the living functions of living organisms that are older than the ability to detect light. "These results suggest that opsin is not limited to Drosophila but may be an unknown taste receptor in mammals, including humans," argued Professor Montell.

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