Distribution,Molecular Structure and Functional Analysis of Carnitine
Transporter (SLC22A5) in Canine Lens Epithelial Cells |
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| Authors: | Hideharu OCHIAI Nobuyuki KANEMAKI Reiichiro SATO Ken ONDA |
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| Institution: | 1)Research Institute of Biosciences, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan;2)Animal Teaching Hospital, Azabu University, Japan;3)Laboratory of Internal Medicine 3, Azabu University, School of Veterinary Medicine, Japan |
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| Abstract: | While carnitine has been reported to have an anti-oxidative role on the ocular surface,
there has been no report on the existence of a carnitine transporter (SLC22A5) in the
lens. Therefore, we investigated the carnitine transport activity of canine lens
epithelial cells (LEC) and determined the molecular structure of canine
SLC22A5. The carnitine transport activity was 7.16 ± 0.48 pmol/mg
protein/30 min. Butyrobetaine, the analogue of carnitine, reduced 30% of the activity at
50 µM. A coding sequence of canine carnitine transporter was 1694 bp
long and was predicted to encode 557 amino acid polypeptides. The deduced amino acid
sequence of canine carnitine transporter showed >80% similarity to that of mouse and
human. Western blot analysis detected the band at 60 kDa in the membrane of lens
epithelial cells. The high content of carnitine in the lens is possibly transported from
aqueous humor by SLC22A5. |
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| Keywords: | carnitine cataract lens epithelial cells oxidative stress SLC22A5 |
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