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Cationic amino acid transport activity and detection of B‐defensin‐1 in canine lens epithelial cells
Author(s) -
OCHIAI H
Publication year - 2012
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2012.s112.x
Subject(s) - defensin , peptide sequence , complementary dna , amino acid , microbiology and biotechnology , arginine , beta defensin , western blot , biology , amino acid transporter , cdna library , biochemistry , transfection , antimicrobial peptides , chemistry , transporter , peptide , gene
Purpose The aim of this study is to investigate the cationic amino acid transport activity in canine lens epithelial cells line (cdLEC).B‐defensins are small cationic peptides possessing a broad range of antimicrobial and physiological activities. The mucosal physical barrier is an important component protecting luminal surfaces from bacteria. Expression of B‐defensins was also examined. Methods Na‐independence of arginine transport activity was measured, and N‐ethylmaleimide (NEM)‐sensitive uptake of arginine was investigated. cDNA sequence of cationic amino acid transporter 1 (CAT1) was determined based on human and mouse CAT1 sequences. RT‐PCR analysis of B‐defensins was carried out. Results NEM‐sensitive component of arginine uptake was detected. cDNA sequence of CAT1 was determined from the cdLEC. The sequence was 2589 bp long and was predicted to encode the 629 amino acid polypeptides. The deduced amino acid sequence showed similarities of 92.1% and 88.6% to those of human and mouse, respectively. Western blot analysis indicated the single band at 70 kDa in membrane protein sample of cdLEC. RT‐PCR analysis confirmed that CAT1 was ubiquitously detected in all tissues examined. Among the B‐defensins, B‐defensin‐1 but not ‐2 and ‐3 were observed in cdLECs and primary culture of lens epithelial cells. Conclusion Lens epithelial cells possess CAT1, and CAT1 may provide substrates for synthesis of B‐defensin‐1.