Cloning and Functional Characterization of Dog OCT1 and OCT2: Another Step in Exploring Species Differences in Organic Cation Transporters

Abstract

OCT1 and OCT2 are polyspecific membrane transporters that are involved in hepatic and renal drug clearance in humans and mice. In this study, we cloned dog OCT1 and OCT2 and compared their function to the human and mouse orthologs. We used liver and kidney RNA to clone dog OCT1 and OCT2. The cloned and the publicly available RNA-Seq sequences differed from the annotated exon-intron structure of OCT1 in the dog genome CanFam3.1. An additional exon between exons 2 and 3 was identified and confirmed by sequencing in six additional dog breeds. Next, dog OCT1 and OCT2 were stably overexpressed in HEK293 cells and the transport kinetics of five drugs were analyzed. We observed strong differences in the transport kinetics between dog and human orthologs. Dog OCT1 transported fenoterol with 12.9-fold higher capacity but 14.3-fold lower affinity (higher KM) than human OCT1. Human OCT1 transported ipratropium with 5.2-fold higher capacity but 8.4-fold lower affinity than dog OCT1. Compared to human OCT2, dog OCT2 showed 10-fold lower transport of fenoterol and butylscopolamine. In conclusion, the functional characterization of dog OCT1 and OCT2 reported here may have implications when using dogs as pre-clinical models as well as for drug therapy in dogs. mehr

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Titel	Cloning and Functional Characterization of Dog OCT1 and OCT2: Another Step in Exploring Species Differences in Organic Cation Transporters
Medien	International Journal of Molecular Sciences
Heft	9
Band	23
ISSN	1422-0067
Verfasser	Marleen Meyer, Simon Falk, Sarah Römer, Clarissa Prinzinger, Sabine Tacke, Joachim Geyer, Prof. Dr. Stefan Simm, Mladen Tzvetkov
Seiten	5100
Veröffentlichungsdatum	5.2022
Zitation	Meyer, Marleen; Falk, Simon; Römer, Sarah; Prinzinger, Clarissa; Tacke, Sabine; Geyer, Joachim; Simm, Stefan; Tzvetkov, Mladen (2022): Cloning and Functional Characterization of Dog OCT1 and OCT2: Another Step in Exploring Species Differences in Organic Cation Transporters. International Journal of Molecular Sciences 23 (9), 5100. DOI: 10.3390/ijms23095100