Functional characterization of mouse cation transporter mOCT2 compared with mOCT1

Mari Kakehi; Noriko Koyabu; Takanori Nakamura; Takeshi Uchiumi; Michihiko Kuwano; Hisakazu Ohtani; Yasufumi Sawada

doi:10.1016/S0006-291X(02)00926-9

Functional characterization of mouse cation transporter mOCT2 compared with mOCT1

Mari Kakehi, Noriko Koyabu, Takanori Nakamura, Takeshi Uchiumi, Michihiko Kuwano, Hisakazu Ohtani, Yasufumi Sawada

Research output: Contribution to journal › Article › peer-review

23 Citations (Scopus)

Abstract

We characterized the function of mouse organic cation transporter OCT2 (TC 2.A.19.1.5) in comparison with that of OCT1 (TC 2.A.19.1.1). Uptake of [³H]1-methyl-4-phenylpyridinium ([³H]MPP⁺) by Xenopus laevis oocytes injected with mOCT1 (Slc22a1) or mOCT2 (Slc22a2) cRNA was attenuated by an increase of extracellular K⁺ concentration and under acidic extracellular conditions. The uptakes of [³H]MPP⁺ via mOCT1 and mOCT2 were saturable, with similar Michaelis constants (K_t) of 10 and 24 μM, respectively. mOCT2 also mediated the uptake of [¹⁴C]tetraethylammonium with a K_t value of 36 μM, which is similar to that of mOCT1. Quinine, tetraethylammonium, cimetidine, procainamide, choline, and N′-methylnicotinamide inhibited the uptake of [³H]MPP⁺ via mOCT1, as well as via mOCT2, and the inhibitory potencies for mOCT1 were comparable to but slightly higher than those for mOCT2. Thus, although the transport properties of mOCT2 are similar to those of mOCT1 in respect to the membrane-potential dependency, pH-sensitivity, and affinities for MPP⁺ and tetraethylammonium, several organic cations had weaker inhibitory effects on [³H]MPP⁺ uptake by mOCT2 than by mOCT1.

Original language	English
Pages (from-to)	644-650
Number of pages	7
Journal	Biochemical and Biophysical Research Communications
Volume	296
Issue number	3
DOIs	https://doi.org/10.1016/S0006-291X(02)00926-9
Publication status	Published - 2002
Externally published	Yes

Keywords

1-Methyl-4-phenylpyridinium
Mouse organic cation transporter 1
Mouse organic cation transporter 2
Tetraethylammonium

ASJC Scopus subject areas

Biophysics
Biochemistry
Molecular Biology
Cell Biology

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10.1016/S0006-291X(02)00926-9

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title = "Functional characterization of mouse cation transporter mOCT2 compared with mOCT1",

abstract = "We characterized the function of mouse organic cation transporter OCT2 (TC 2.A.19.1.5) in comparison with that of OCT1 (TC 2.A.19.1.1). Uptake of [3H]1-methyl-4-phenylpyridinium ([3H]MPP+) by Xenopus laevis oocytes injected with mOCT1 (Slc22a1) or mOCT2 (Slc22a2) cRNA was attenuated by an increase of extracellular K+ concentration and under acidic extracellular conditions. The uptakes of [3H]MPP+ via mOCT1 and mOCT2 were saturable, with similar Michaelis constants (Kt) of 10 and 24 μM, respectively. mOCT2 also mediated the uptake of [14C]tetraethylammonium with a Kt value of 36 μM, which is similar to that of mOCT1. Quinine, tetraethylammonium, cimetidine, procainamide, choline, and N′-methylnicotinamide inhibited the uptake of [3H]MPP+ via mOCT1, as well as via mOCT2, and the inhibitory potencies for mOCT1 were comparable to but slightly higher than those for mOCT2. Thus, although the transport properties of mOCT2 are similar to those of mOCT1 in respect to the membrane-potential dependency, pH-sensitivity, and affinities for MPP+ and tetraethylammonium, several organic cations had weaker inhibitory effects on [3H]MPP+ uptake by mOCT2 than by mOCT1.",

keywords = "1-Methyl-4-phenylpyridinium, Mouse organic cation transporter 1, Mouse organic cation transporter 2, Tetraethylammonium",

author = "Mari Kakehi and Noriko Koyabu and Takanori Nakamura and Takeshi Uchiumi and Michihiko Kuwano and Hisakazu Ohtani and Yasufumi Sawada",

year = "2002",

doi = "10.1016/S0006-291X(02)00926-9",

language = "English",

volume = "296",

pages = "644--650",

journal = "Biochemical and Biophysical Research Communications",

issn = "0006-291X",

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T1 - Functional characterization of mouse cation transporter mOCT2 compared with mOCT1

AU - Kakehi, Mari

AU - Koyabu, Noriko

AU - Nakamura, Takanori

AU - Uchiumi, Takeshi

AU - Kuwano, Michihiko

AU - Ohtani, Hisakazu

AU - Sawada, Yasufumi

PY - 2002

Y1 - 2002

N2 - We characterized the function of mouse organic cation transporter OCT2 (TC 2.A.19.1.5) in comparison with that of OCT1 (TC 2.A.19.1.1). Uptake of [3H]1-methyl-4-phenylpyridinium ([3H]MPP+) by Xenopus laevis oocytes injected with mOCT1 (Slc22a1) or mOCT2 (Slc22a2) cRNA was attenuated by an increase of extracellular K+ concentration and under acidic extracellular conditions. The uptakes of [3H]MPP+ via mOCT1 and mOCT2 were saturable, with similar Michaelis constants (Kt) of 10 and 24 μM, respectively. mOCT2 also mediated the uptake of [14C]tetraethylammonium with a Kt value of 36 μM, which is similar to that of mOCT1. Quinine, tetraethylammonium, cimetidine, procainamide, choline, and N′-methylnicotinamide inhibited the uptake of [3H]MPP+ via mOCT1, as well as via mOCT2, and the inhibitory potencies for mOCT1 were comparable to but slightly higher than those for mOCT2. Thus, although the transport properties of mOCT2 are similar to those of mOCT1 in respect to the membrane-potential dependency, pH-sensitivity, and affinities for MPP+ and tetraethylammonium, several organic cations had weaker inhibitory effects on [3H]MPP+ uptake by mOCT2 than by mOCT1.

AB - We characterized the function of mouse organic cation transporter OCT2 (TC 2.A.19.1.5) in comparison with that of OCT1 (TC 2.A.19.1.1). Uptake of [3H]1-methyl-4-phenylpyridinium ([3H]MPP+) by Xenopus laevis oocytes injected with mOCT1 (Slc22a1) or mOCT2 (Slc22a2) cRNA was attenuated by an increase of extracellular K+ concentration and under acidic extracellular conditions. The uptakes of [3H]MPP+ via mOCT1 and mOCT2 were saturable, with similar Michaelis constants (Kt) of 10 and 24 μM, respectively. mOCT2 also mediated the uptake of [14C]tetraethylammonium with a Kt value of 36 μM, which is similar to that of mOCT1. Quinine, tetraethylammonium, cimetidine, procainamide, choline, and N′-methylnicotinamide inhibited the uptake of [3H]MPP+ via mOCT1, as well as via mOCT2, and the inhibitory potencies for mOCT1 were comparable to but slightly higher than those for mOCT2. Thus, although the transport properties of mOCT2 are similar to those of mOCT1 in respect to the membrane-potential dependency, pH-sensitivity, and affinities for MPP+ and tetraethylammonium, several organic cations had weaker inhibitory effects on [3H]MPP+ uptake by mOCT2 than by mOCT1.

KW - 1-Methyl-4-phenylpyridinium

KW - Mouse organic cation transporter 1

KW - Mouse organic cation transporter 2

KW - Tetraethylammonium

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DO - 10.1016/S0006-291X(02)00926-9

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AN - SCOPUS:0036385715

SN - 0006-291X

VL - 296

SP - 644

EP - 650

JO - Biochemical and Biophysical Research Communications

JF - Biochemical and Biophysical Research Communications

IS - 3

ER -

Functional characterization of mouse cation transporter mOCT2 compared with mOCT1

Abstract

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