The Central Polybasic Region of the Soluble SNARE (SolubleN-Ethylmaleimide-sensitive Factor Attachment Protein Receptor) Vam7 Affects Binding to Phosphatidylinositol 3-Phosphate by the PX (Phox Homology) Domain

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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Munc18-1 domain-1 controls vesicle docking and secretion by interacting with syntaxin-1 and chaperoning it to the plasma membrane

Molecular Biology of the Cell ◽

10.1091/mbc.e11-02-0135 ◽

2011 ◽

Vol 22 (21) ◽

pp. 4134-4149 ◽

Cited By ~ 31

Author(s):

Gayoung A. Han ◽

Nancy T. Malintan ◽

Ner Mu Nar Saw ◽

Lijun Li ◽

Liping Han ◽

...

Keyword(s):

Molecular Chaperone ◽

Dense Core ◽

Dense Core Vesicle ◽

Attachment Protein ◽

Vesicle Docking ◽

Protein Receptor ◽

Sensitive Factor ◽

Intracellular Expression ◽

Factor Attachment Protein Receptor

Munc18-1 plays pleiotropic roles in neurosecretion by acting as 1) a molecular chaperone of syntaxin-1, 2) a mediator of dense-core vesicle docking, and 3) a priming factor for soluble N-ethylmaleimide–sensitive factor attachment protein receptor–mediated membrane fusion. However, how these functions are executed and whether they are correlated remains unclear. Here we analyzed the role of the domain-1 cleft of Munc18-1 by measuring the abilities of various mutants (D34N, D34N/M38V, K46E, E59K, K46E/E59K, K63E, and E66A) to bind and chaperone syntaxin-1 and to restore the docking and secretion of dense-core vesicles in Munc18-1/-2 double-knockdown cells. We identified striking correlations between the abilities of these mutants to bind and chaperone syntaxin-1 with their ability to restore vesicle docking and secretion. These results suggest that the domain-1 cleft of Munc18-1 is essential for binding to syntaxin-1 and thereby critical for its chaperoning, docking, and secretory functions. Our results demonstrate that the effect of the alleged priming mutants (E59K, D34N/M38V) on exocytosis can largely be explained by their reduced syntaxin-1–chaperoning functions. Finally, our data suggest that the intracellular expression and distribution of syntaxin-1 determines the level of dense-core vesicle docking.

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Endosomal and Phagosomal SNAREs

Physiological Reviews ◽

10.1152/physrev.00037.2017 ◽

2018 ◽

Vol 98 (3) ◽

pp. 1465-1492 ◽

Cited By ~ 21

Author(s):

Ilse Dingjan ◽

Peter T. A. Linders ◽

Danielle R. J. Verboogen ◽

Natalia H. Revelo ◽

Martin ter Beest ◽

...

Keyword(s):

Intracellular Transport ◽

Snare Proteins ◽

Intracellular Pathogens ◽

Snare Protein ◽

Attachment Protein ◽

System A ◽

Protein Receptor ◽

Sensitive Factor ◽

Organelle Communication ◽

Factor Attachment Protein Receptor

The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein family is of vital importance for organelle communication. The complexing of cognate SNARE members present in both the donor and target organellar membranes drives the membrane fusion required for intracellular transport. In the endocytic route, SNARE proteins mediate trafficking between endosomes and phagosomes with other endosomes, lysosomes, the Golgi apparatus, the plasma membrane, and the endoplasmic reticulum. The goal of this review is to provide an overview of the SNAREs involved in endosomal and phagosomal trafficking. Of the 38 SNAREs present in humans, 30 have been identified at endosomes and/or phagosomes. Many of these SNAREs are targeted by viruses and intracellular pathogens, which thereby reroute intracellular transport for gaining access to nutrients, preventing their degradation, and avoiding their detection by the immune system. A fascinating picture is emerging of a complex transport network with multiple SNAREs being involved in consecutive trafficking routes.

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