Author Interviews, Genetic Research, PNAS, UCSD / 20.04.2023
We Are Able to See Thanks to a Protein Acquired from Bacteria
MedicalResearch.com Interview with:
Chinmay Kalluraya
a Selma and Robert Silagi Award for Undergraduate Excellence winner
UC San Diego and now a graduate student at MIT
and
Matt Daugherty Ph.D
Associate Professor
University of California, San Diego
Department of Molecular Biology, School of Biological Sciences
La Jolla CA, 92093-0377
MedicalResearch.com: What is the background for this study? Would you explain the role of retinoid-binding protein?
Response: We were broadly interested in discovering instances of bacterial genes that have been acquired by diverse animal genomes over millions of years of evolution by the process of horizontal gene transfer (HGT). Since these events are quite rare and most previous discoveries have been serendipitous, we developed computational methods to identify genes acquired by HGT in animals. One of the exciting discoveries from our work was that vertebrate IRBP appeared to have originated in bacteria and is now a critical component of the vertebrate visual cycle, so this paper focuses on that one discovery.
IRBP or interphotoreceptor retinoid binding protein is an important protein present in the space between two major cell types in our eyes, photoreceptor cells and RPE cells. Our ability to see involves an intricate set of steps where light is first sensed by causing a change (isomerization) in the chemical structure of molecules in the eye called retinoids. This sensing of light occurs in our photoreceptor cells. Following this change in the chemical structure, the retinoid needs to be recycled back to the chemical structure that can again sense light. This recycling occurs in RPE cells. IRBP performs the essential function of shuttling retinoids between the photoreceptors and the RPE cells, which allows the cycle of sensing and regeneration to work. Supporting its importance, mutations in IRBP (also known as retinol binding protein 3 or RBP3) can cause several severe human eye diseases.
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