scholarly journals VAMP3 and VAMP8 regulate the development and functionality of parasitophorous vacuoles housing Leishmania amazonensis

2020 ◽  
Author(s):  
Olivier Séguin ◽  
Linh Thuy Mai ◽  
Sidney W. Whiteheart ◽  
Simona Stäger ◽  
Albert Descoteaux
Keyword(s):  
Host Cell ◽  
Leishmania Amazonensis ◽  
Phagocytic Cells ◽  
Attachment Protein ◽  
Receptor Proteins ◽  
Cross Presentation ◽  
Data Support ◽  
Protein Receptor ◽  
Sensitive Factor ◽  
Factor Attachment Protein Receptor

ABSTRACTTo colonize mammalian phagocytic cells, the parasite Leishmania remodels phagosomes into parasitophorous vacuoles that can be either tight-fitting individual or communal. The molecular and cellular bases underlying the biogenesis and functionality of these two types of vacuoles are poorly understood. In this study, we investigated the contribution of host cell Soluble N-ethylmaleimide-sensitive-factor Attachment protein REceptor proteins in the expansion and functionality of communal vacuoles as well as on the replication of the parasite. The differential recruitment patterns of Soluble N-ethylmaleimide-sensitive-factor Attachment protein REceptor to communal vacuoles harboring L. amazonensis and to individual vacuoles housing L. major led us to further investigate the contribution of VAMP3 and VAMP8 in the interaction of Leishmania with its host cell. We show that whereas VAMP8 contributes to optimal expansion of communal vacuoles, VAMP3 negatively regulates L. amazonensis replication, vacuole size, as well as antigen cross-presentation. In contrast, neither proteins has an impact on the fate of L. major. Collectively, our data support a role for both VAMP3 and VAMP8 in the development and functionality of L. amazonensis-harboring communal parasitophorous vacuoles.

scholarly journals SNARE zippering

2016 ◽  
Vol 36 (3) ◽  
Author(s):  
Xiaochu Lou ◽  
Yeon-Kyun Shin
Keyword(s):  
Recent Progress ◽  
Snare Complex ◽  
Intracellular Membrane ◽  
Attachment Protein ◽  
Receptor Proteins ◽  
Protein Receptor ◽  
Sensitive Factor ◽  
Associated Proteins ◽  
Intracellular Membrane Fusion ◽  
Factor Attachment Protein Receptor

SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins are a highly conserved set of membrane-associated proteins that mediate intracellular membrane fusion. Cognate SNAREs from two separate membranes zipper to facilitate membrane apposition and fusion. Though the stable post-fusion conformation of SNARE complex has been extensively studied with biochemical and biophysical means, the pathway of SNARE zippering has been elusive. In this review, we describe some recent progress in understanding the pathway of SNARE zippering. We particularly focus on the half-zippered intermediate, which is most likely to serve as the main point of regulation by the auxiliary factors.

scholarly journals Syntaxin 16 is a master recruitment factor for cytokinesis

2013 ◽  
Vol 24 (23) ◽  
pp. 3663-3674 ◽  
Author(s):  
Hélia Neto ◽  
Alexandra Kaupisch ◽  
Louise L. Collins ◽  
Gwyn W. Gould
Keyword(s):  
Membrane Vesicles ◽  
Attachment Protein ◽  
Recycling Endosome ◽  
Endosomal Sorting ◽  
Escrt Machinery ◽  
Protein Receptor ◽  
Sensitive Factor ◽  
Late Telophase ◽  
Intracellular Organelles ◽  
Factor Attachment Protein Receptor

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.

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

2011 ◽  
Vol 22 (21) ◽  
pp. 4134-4149 ◽  
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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