Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.10.244822v1?rss=1 Authors: Wiriyasermkul, P., Moriyama, S., Tanaka, Y., Kongpracha, P., Nakamae, N., Suzuki, M., Kimura, T., Mita, M., Sasabe, J., Nagamori, S. Abstract: Delay in diagnosis of renal injury has profound impacts on morbidity and mortality. Damage of proximal tubules by the injury impairs not only individual membrane transport proteins but also coordinated transport systems. In this study, we analyzed the proteome of apical membrane of proximal tubular epithelium from the mouse kidney with early ischemiareperfusion injury (IRI), a well-known acute kidney injury (AKI) model. The proteome showed drastic elevations of the injury-responsive proteins and depressions of abundant transporters, leading to the prediction of biomarkers for early IRI. As the benchmark of our in-depth analysis from the proteome, we characterized transporters for D-serine, a promising renal diseases' biomarker. Using cell-based and cell-free methods, we identified sodium-coupled monocarboxylate transporters (SMCTs) as the D-serine transporters. This finding enlightens the role of non-canonical substrate transport and clarifies the D-serine transport systems in the kidney. Our approaches can be applied for investigation of other membrane transport systems. Copy rights belong to original authors. Visit the link for more info