N-acetylamino acid utilization by kidney aminoacylase-1.
Mammalian aminoacylase-1 (Acy1) participates in the breakdown of N-acetylated amino acids during intracellular protein catabolism. Acy1 is most abundantly expressed in the kidney tubular epithelium. Lately, Acy1 deficiency was identified in children with increased urinary excretion of several N-acetylamino acids. Here we report detailed N-acetylamino acid specificity profiles for human and porcine Acy1 based on steady state kinetic measurements. We found that LLC-PK1 cells, a model of the porcine kidney proximal tubular epithelium, robustly express Acy1. For the first time, we demonstrate uptake and utilization of N-acteylleucine and -methionine in replacement of the free amino acid, respectively, in cultured epithelial cells. Our data are consistent with a specific role of kidney Acy1 in the salvage of amino acids originating from systemic degradation of N-acetylated proteins.
Lindner
Holger A
HA
Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada. holger.lindner@cnrc-nrc.gc.ca
Täfler-Naumann
Margot
M
Röhm
Klaus-Heinrich
KH
D000581:Amidohydrolases / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D018374:LLC-PK1 Cells; D051381:Rats
D000596:Amino Acids; D000581:Amidohydrolases; C019672:aminoacylase I