June 2015
Volume 56, Issue 7
Free
ARVO Annual Meeting Abstract  |   June 2015
RDH13L, an enzyme responsible for the aldehyde-alcohol redox coupling reaction (AL-OL coupling reaction) to supply 11-cis retinal in the carp cone retinoid cycle
Author Affiliations & Notes
  • Shinya Sato
    Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO
  • Sadaharu Miyazono
    Department of Sensory Physiology, Asahikawa Medical University, Asahikawa, Japan
  • Shuji Tachibanaki
    Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
    Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
  • Satoru Kawamura
    Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
    Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
  • Footnotes
    Commercial Relationships Shinya Sato, None; Sadaharu Miyazono, None; Shuji Tachibanaki, None; Satoru Kawamura, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2015, Vol.56, 5514. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Shinya Sato, Sadaharu Miyazono, Shuji Tachibanaki, Satoru Kawamura; RDH13L, an enzyme responsible for the aldehyde-alcohol redox coupling reaction (AL-OL coupling reaction) to supply 11-cis retinal in the carp cone retinoid cycle. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):5514.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: Cones, unlike rods, have 11-cis retinol oxidation activity that can promote regeneration of cone visual pigments and thus dark adaptation of cones. However, the responsible enzyme(s) for this reaction is still not clear. We previously reported a novel, very efficient 11-cis retinol oxidation activity in carp cone inner segments (aldehyde-alcohol redox coupling; AL-OL coupling) that utilizes hydrophobic aldehydes, not NADP+ or NAD+, as oxidants. In this study, we tried to identify and characterize an enzyme responsible for the AL-OL coupling using biochemical methods.

Methods: Cones were purified from common carp retina (Cyprinus carpio) by using Percoll density gradient centrifugation. For purification of the enzyme, proteins in cones were fractionated by FPLC and native-PAGE. A 37 kDa protein in the sample was identified as retinol dehydrogenase 13-like (RDH13L) by mass spectrometry. The AL-OL coupling activity of RDH13L was studied using recombinant RDH13L proteins. NADP(H) bound to recombinant RDH13L was quantified by HPLC. Subcellular localization of RDH13L in carp cones was studied by immunocytochemistry. The AL-OL coupling activity in mouse homologs of carp RDH13L was examined using recombinant mouse RDH proteins.

Results: RDH13L was identified as a candidate protein responsible for the AL-OL coupling. Recombinant RDH13L showed AL-OL coupling activity. Substrate specificity and subcellular localization of RDH13L were similar to those previously observed for the AL-OL coupling activity of carp cones. Recombinant RDH13L contained tightly bound NADP+. Mouse RDH14 showed AL-OL coupling activity. In addition to the AL-OL coupling, carp RDH13L and mouse RDH14 also exhibited conventional RDH activity, i.e., NADP+-dependent 11-cis retinol oxidation activity. However, temperature dependences of these two reactions were different.

Conclusions: We identified proteins having a dual mechanism of 11-cis retinol oxidation from both carp and mice. These proteins might contribute to an efficient cone pigment regeneration. However, because our study is limited to biochemical analyses, it is still not clear how much these proteins have an impact on cone function in living animals. Physiological studies will be needed for further analysis.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×