Syntaxin 8 has two functionally distinct di-leucine-based motifs

Cellular & Molecular Biology Letters

Kimio Akagawa²  Kei Suga²  Kazuo Kasai³  Tetsuro Izumi¹ 

[1] Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan$$;Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan$$;Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan$$Toyama Chemical Co., Ltd., Shinjuku, Tokyo, Japan$$Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan$$

关键词: Syntaxin;    Di-leucine-based motif;    Endocytosis;    Exocytosis;   

DOI  :  10.2478/s11658-007-0043-9

学科分类：分子生物学，细胞生物学和基因

来源: Uniwersytet Wroclawski * Wydzial Biotechnologii / University of Wroclaw, Faculty of Biotechnology

【 摘 要 】

Syntaxin 8 has been shown to form the SNARE complex with syntaxin 7, vti1b and endobrevin. These have been shown to function as the machinery for the homotypic fusion of late endosomes. Recently, we showed that syntaxins 7 and 8 cycle through the plasma membrane, and that the di-leucine-based motifs in the cytoplasmic domain of syntaxins 7 and 8 respectively function in their endocytic and exocytic processes. However, we could not elucidate the mechanism by which syntaxin 8 cycles through the plasma membrane. In this study, we constructed several different syntaxin 8 molecules by mutating putative di-leucine-based motifs, and analyzed their intracellular localization and trafficking. We found a di-leucine-based motif in the cytoplasmic domain of syntaxin 8. It is similar to that of syntaxin 7, and functions in its endocytosis. These results suggest that in the cytoplasmic domain, syntaxin 8 has two functionally distinct di-leucine-based motifs that act independently in its endocytic and exocytic processes. This is the first report on two di-leucine-based motifs in the same molecule acting independently in distinct transport pathways.

【 授权许可】

Unknown