scholarly journals Synip Arrests SolubleN-Ethylmaleimide-sensitive Factor Attachment Protein Receptor (SNARE)-dependent Membrane Fusion as a Selective Target Membrane SNARE-binding Inhibitor

2013 ◽  
Vol 288 (26) ◽  
pp. 18885-18893 ◽  
Author(s):  
Haijia Yu ◽  
Shailendra S. Rathore ◽  
Jingshi Shen
1998 ◽  
Vol 141 (7) ◽  
pp. 1489-1502 ◽  
Author(s):  
Jesse C. Hay ◽  
Judith Klumperman ◽  
Viola Oorschot ◽  
Martin Steegmaier ◽  
Christin S. Kuo ◽  
...  

ER-to-Golgi transport, and perhaps intraGolgi transport involves a set of interacting soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) proteins including syntaxin 5, GOS-28, membrin, rsec22b, and rbet1. By immunoelectron microscopy we find that rsec22b and rbet1 are enriched in COPII-coated vesicles that bud from the ER and presumably fuse with nearby vesicular tubular clusters (VTCs). However, all of the SNAREs were found on both COPII- and COPI-coated membranes, indicating that similar SNARE machinery directs both vesicle pathways. rsec22b and rbet1 do not appear beyond the first Golgi cisterna, whereas syntaxin 5 and membrin penetrate deeply into the Golgi stacks. Temperature shifts reveal that membrin, rsec22b, rbet1, and syntaxin 5 are present together on membranes that rapidly recycle between peripheral and Golgi-centric locations. GOS-28, on the other hand, maintains a fixed localization in the Golgi. By immunoprecipitation analysis, syntaxin 5 exists in at least two major subcomplexes: one containing syntaxin 5 (34-kD isoform) and GOS-28, and another containing syntaxin 5 (41- and 34-kD isoforms), membrin, rsec22b, and rbet1. Both subcomplexes appear to involve direct interactions of each SNARE with syntaxin 5. Our results indicate a central role for complexes among rbet1, rsec22b, membrin, and syntaxin 5 (34 and 41 kD) at two membrane fusion interfaces: the fusion of ER-derived vesicles with VTCs, and the assembly of VTCs to form cis-Golgi elements. The 34-kD syntaxin 5 isoform, membrin, and GOS-28 may function in intraGolgi transport.


2005 ◽  
Vol 16 (10) ◽  
pp. 4755-4764 ◽  
Author(s):  
Akhil Bhalla ◽  
Ward C. Tucker ◽  
Edwin R. Chapman

Ca2+-triggered exocytosis of synaptic vesicles is controlled by the Ca2+-binding protein synaptotagmin (syt) I. Fifteen additional isoforms of syt have been identified. Here, we compared the abilities of three syt isoforms (I, VII, and IX) to regulate soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion in vitro in response to divalent cations. We found that different isoforms of syt couple distinct ranges of Ca2+, Ba2+, and Sr2+ to membrane fusion; syt VII was ∼400-fold more sensitive to Ca2+ than was syt I. Omission of phosphatidylserine (PS) from both populations of liposomes completely abrogated the ability of all three isoforms of syt to stimulate fusion. Mutations that selectively inhibit syt·target-SNARE (t-SNARE) interactions reduced syt stimulation of fusion. Using Sr2+ and Ba2+, we found that binding of syt to PS and t-SNAREs can be dissociated from activation of fusion, uncovering posteffector-binding functions for syt. Our data demonstrate that different syt isoforms are specialized to sense different ranges of divalent cations and that PS is an essential effector of Ca2+·syt action.


2017 ◽  
Vol 45 (6) ◽  
pp. 1271-1277 ◽  
Author(s):  
Kamilla M.E. Laidlaw ◽  
Rachel Livingstone ◽  
Mohammed Al-Tobi ◽  
Nia J. Bryant ◽  
Gwyn W. Gould

Trafficking within eukaryotic cells is a complex and highly regulated process; events such as recycling of plasma membrane receptors, formation of multivesicular bodies, regulated release of hormones and delivery of proteins to membranes all require directionality and specificity. The underpinning processes, including cargo selection, membrane fusion, trafficking flow and timing, are controlled by a variety of molecular mechanisms and engage multiple families of lipids and proteins. Here, we will focus on control of trafficking processes via the action of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family of proteins, in particular their regulation by phosphorylation. We will describe how these proteins are controlled in a range of regulated trafficking events, with particular emphasis on the insulin-stimulated delivery of glucose transporters to the surface of adipose and muscle cells. Here, we focus on a few examples of SNARE phosphorylation which exemplify distinct ways in which SNARE machinery phosphorylation may regulate membrane fusion.


2013 ◽  
Vol 24 (23) ◽  
pp. 3663-3674 ◽  
Author(s):  
Hélia Neto ◽  
Alexandra Kaupisch ◽  
Louise L. Collins ◽  
Gwyn W. Gould

Recently it was shown that both recycling endosome and endosomal sorting complex required for transport (ESCRT) components are required for cytokinesis, in which they are believed to act in a sequential manner to bring about secondary ingression and abscission, respectively. However, it is not clear how either of these complexes is targeted to the midbody and whether their delivery is coordinated. The trafficking of membrane vesicles between different intracellular organelles involves the formation of soluble N-ethylmalei­mide–sensitive factor attachment protein receptor (SNARE) complexes. Although membrane traffic is known to play an important role in cytokinesis, the contribution and identity of intracellular SNAREs to cytokinesis remain unclear. Here we demonstrate that syntaxin 16 is a key regulator of cytokinesis, as it is required for recruitment of both recycling endosome–associated Exocyst and ESCRT machinery during late telophase, and therefore that these two distinct facets of cytokinesis are inextricably linked.


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