Syntaxin 7, a Novel Syntaxin Member Associated with the Early Endosomal Compartment*
- From the Membrane Biology Laboratory, Institute of Molecular and Cell Biology, Singapore 119076, Singapore
Abstract
Members of the syntaxin family are key molecules involved in diverse vesicle docking/fusion events. We report here the molecular, biochemical, and cell biological characterizations of a novel member (syntaxin 7) of the syntaxin family. Syntaxin 7 is structurally related to all known syntaxins. Within a 79-residue region preceding the C-terminal hydrophobic tail, syntaxin 7 is 35, 34, 34, 34, 25, and 19% identical to syntaxins 1, 2, 3, 4, 5, and 6, respectively. Northern blot analysis showed that syntaxin 7 is widely expressed. Indirect immunofluorescence microscopy revealed that syntaxin 7 is primarily associated with the early endosome. In vitro binding assays established that syntaxin 7 in membrane extracts interacts with immobilized recombinant α-solubleN-ethylmaleimide-sensitive factor attachment proteins fused to glutathione S-transferase. Our results highlight the general importance of members of the syntaxin family in protein trafficking and provide new avenues for future functional and mechanistic studies of this first endosomal syntaxin as well as the endocytotic pathway.
Footnotes
-
↵* This work was funded by the Institute of Molecular and Cell Biology, NUS (to W. H.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) AF031430.
-
↵‡ To whom correspondence should be addressed: Institute of Molecular and Cell Biology, 15 Lower Kent Ridge Rd., Singapore 119076, Singapore. Tel.: 65-778-6827; Fax: 65-779-1117; E-mail:mcbhwj{at}leonis.nus.sg.
-
↵1 The abbreviations used are: SNARE, solubleN-ethylmaleimide-sensitive factor attachment protein receptor; VAMP, vesicle-associated membrane protein; SNAP, solubleN-ethylmaleimide-sensitive factor attachment protein; CHO, Chinese hamster ovary; NRL, normal rat liver; MDCK, Madin-Darby canine kidney; BFA, brefeldin A; GST, glutathione S-transferase; PBS, phosphate-buffered saline; PAGE, polyacrylamide gel electrophoresis; MTOC, microtubule organizing center.
-
- Received August 18, 1997.
- Revision received October 21, 1997.
- The American Society for Biochemistry and Molecular Biology, Inc.
