Yukimi Horii, Satoru Nogami, Yoji Kawano, Takako Kaneko-Kawano, Natsuko Ohtomo, Tomoaki Tomiya, Hiromichi Shirataki
Department of Molecular and Cell Biology, Graduate School of Medicine, Dokkyo Medical University, Tochigi, Japan.
Cell structure and function 2012Intracellular vesicle traffic plays an essential role in the establishment and maintenance of organelle identity and biosynthetic transport. We have identified α-taxilin as a binding partner of the syntaxin family, which is involved in intracellular vesicle traffic. Recently, we have found that α-taxilin is over-expressed in malignant tissues including hepatocellular carcinoma and renal cell carcinoma. However, a precise role of α-taxilin in intracellular vesicle traffic and carcinogenesis remains unclear. Then, we first investigated here the intracellular distribution of α-taxilin in Hela cells. Immunofluorescence studies showed that α-taxilin distributes throughout the cytoplasm and exhibits a tubulo-vesicular pattern. Biochemical studies showed that α-taxilin is abundantly localized on intracellular components as a peripheral membrane protein. Moreover, we found that α-taxilin distributes in microtubule-dependent and syntaxin-independent manners, that α-taxilin directly binds to polymerized tubulin in vitro, and that N-ethylmaleimide but not brefeldin A affects the intracellular distribution of α-taxilin. These results indicate that α-taxilin is localized on intracellular components in a syntaxin-independent manner and that the α-taxilin-containing intracellular components are associated with the microtubule cytoskeleton and suggest that α-taxilin functions as a linker protein between the α-taxilin-containing intracellular components and the microtubule cytoskeleton.
Yukimi Horii, Satoru Nogami, Yoji Kawano, Takako Kaneko-Kawano, Natsuko Ohtomo, Tomoaki Tomiya, Hiromichi Shirataki. Interaction of α-taxilin localized on intracellular components with the microtubule cytoskeleton. Cell structure and function. 2012;37(2):111-26
PMID: 22785156
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