Differential subcellular localization of endogenous and transfected soluble epoxide hydrolase in mammalian cells: evidence for isozyme variants

FEBS Letters

Mullen, Robert T⁴  Hammock, Bruce D²  Oesch, Franz³  Grant, David F¹  Trelease, Richard N⁴  Arand, Michael³  Duerk, Heike³ 

[1] Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, 4301 W. Markham, Slot 638, Little Rock, AR 72205-7199, USA;Departments of Entomology and Environmental Toxicology, University of California, Davis, CA 95616-1527, USA;Institute of Toxicology, University of Mainz, Obere Zahlbacherstr. 67, D-55131 Mainz, Germany;Department of Plant Biology, Arizona State University, Tempe, AZ 85287-1601, USA

关键词: Clofibrate;    Epoxide hydrolase;    Peroxisome;    Peroxisome targeting signal;   

DOI  :  10.1016/S0014-5793(99)00142-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Endogenous, constitutive soluble epoxide hydrolase in mice 3T3 cells was localized via immunofluorescence microscopy exclusively in peroxisomes, whereas transiently expressed mouse soluble epoxide hydrolase (from clofibrate-treated liver) accumulated only in the cytosol of 3T3 and HeLa cells. When the C-terminal Ile of mouse soluble epoxide hydrolase was mutated to generate a prototypic putative type 1 PTS (-SKI to -SKL), the enzyme targeted to peroxisomes. The possibility that soluble epoxide hydrolase-SKI was sorted slowly to peroxiosmes from the cytosol was examined by stably expressing rat soluble epoxide hydrolase-SKI appended to the green fluorescent protein. Green fluorescent protein soluble epoxide hydrolase-SKI was strictly cytosolic, indicating that -SKI was not a temporally inefficient putative type 1 PTS. Import of soluble epoxide hydrolase-SKI into peroxisomes in plant cells revealed that the context of -SKI on soluble epoxide hydrolase was targeting permissible. These results show that the C-terminal -SKI is a non-functional putative type 1 PTS on soluble epoxide hydrolase and suggest the existence of distinct cytosolic and peroxisomal targeting variants of soluble epoxide hydrolase in mouse and rat.

【 授权许可】

Unknown