Syntaxin 11 is an atypical SNARE abundant in the immune system.
Several classes of proteins have been identified that mediate and regulate membrane dynamics throughout the eukaryotic cell. One class of membrane-trafficking proteins, referred to as soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs), have been implicated in mediating membrane fusion. Here we characterize syntaxin 11, an atypical syntaxin family member lacking a transmembrane domain. Syntaxin 11 was found to be enriched in tissues of the immune system including thymus, spleen and lymphnodes; however, lower levels of the protein are found in other tissues. Using immunofluorescence and electron microscopy techniques, we demonstrate that syntaxin 11 associates with intermediate compartment (IC) and post-Golgi membranes through a putative palmitoylation domain, as well as through formation of the 100-kDa complex with, as of yet, unidentified proteins. The coiled-coil forming H3 domain is required for the formation of the 100-kDa complex, and this complex can be dissociated upon addition of alphaSNAP. Thus, while the precise function of syntaxin 11 remains to be elucidated, it may be particularly important in regulating membrane dynamics of the immune system.
Prekeris
R
R
Howard Hughes Medical Institute, Department of Molecular and Cellular Physiology, Stanford University School of Medicine, CA 94305-5428, USA.
Klumperman
J
J
Scheller
R H
RH
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D006056:Golgi Apparatus / Q000737:chemistry / Q000187:drug effects; D007425:Intracellular Membranes / Q000737:chemistry; D008221:Lymphoid Tissue / Q000737:chemistry* / Q000166:cytology; D008264:Macrophages / Q000737:chemistry* / Q000166:cytology; D008565:Membrane Proteins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D015739:Nocodazole / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D050765:Qa-SNARE Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins
D000970:Antineoplastic Agents; D002352:Carrier Proteins; D008565:Membrane Proteins; D011500:Protein Synthesis Inhibitors; D050765:Qa-SNARE Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins; D020126:Brefeldin A; D015739:Nocodazole