scholarly journals Annexin A2 Egress during Calcium-Regulated Exocytosis in Neuroendocrine Cells

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2059 ◽  
Author(s):  
Marion Gabel ◽  
Cathy Royer ◽  
Tamou Thahouly ◽  
Valérie Calco ◽  
Stéphane Gasman ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Chromaffin Cells ◽  
Spatial Organization ◽  
Lipid Binding ◽  
Annexin A2 ◽  
Neuroendocrine Cells ◽  
Outer Face ◽  
Tissue Plasminogen

Annexin A2 (AnxA2) is a calcium- and lipid-binding protein involved in neuroendocrine secretion where it participates in the formation and/or stabilization of lipid micro-domains required for structural and spatial organization of the exocytotic machinery. We have recently described that phosphorylation of AnxA2 on Tyr23 is critical for exocytosis. Considering that Tyr23 phosphorylation is known to promote AnxA2 externalization to the outer face of the plasma membrane in different cell types, we examined whether this phenomenon occurred in neurosecretory chromaffin cells. Using immunolabeling and biochemical approaches, we observed that nicotine stimulation triggered the egress of AnxA2 to the external leaflets of the plasma membrane in the vicinity of exocytotic sites. AnxA2 was found co-localized with tissue plasminogen activator, previously described on the surface of chromaffin cells following secretory granule release. We propose that AnxA2 might be a cell surface tissue plasminogen activator receptor for chromaffin cells, thus playing a role in autocrine or paracrine regulation of exocytosis.

scholarly journals Annexin A2–dependent actin bundling promotes secretory granule docking to the plasma membrane and exocytosis

2015 ◽  
Vol 210 (5) ◽  
pp. 785-800 ◽  
Author(s):  
Marion Gabel ◽  
Franck Delavoie ◽  
Valérie Demais ◽  
Cathy Royer ◽  
Yannick Bailly ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Spatial Organization ◽  
Electron Tomography ◽  
Secretory Granules ◽  
Membrane Lipid ◽  
Lipid Binding ◽  
Annexin A2 ◽  
Cortical Actin ◽  
Lipid Microdomains ◽  
Lipid Domain

Annexin A2, a calcium-, actin-, and lipid-binding protein involved in exocytosis, mediates the formation of lipid microdomains required for the structural and spatial organization of fusion sites at the plasma membrane. To understand how annexin A2 promotes this membrane remodeling, the involvement of cortical actin filaments in lipid domain organization was investigated. 3D electron tomography showed that cortical actin bundled by annexin A2 connected docked secretory granules to the plasma membrane and contributed to the formation of GM1-enriched lipid microdomains at the exocytotic sites in chromaffin cells. When an annexin A2 mutant with impaired actin filament–bundling activity was expressed, the formation of plasma membrane lipid microdomains and the number of exocytotic events were decreased and the fusion kinetics were slower, whereas the pharmacological activation of the intrinsic actin-bundling activity of endogenous annexin A2 had the opposite effects. Thus, annexin A2–induced actin bundling is apparently essential for generating active exocytotic sites.

scholarly journals Annexin A2: A Tissue Plasminogen Activator Amplifier for Thrombolytic Stroke Therapy

Stroke ◽  
2010 ◽  
Vol 41 (10, Supplement 1) ◽  
pp. S54-S58 ◽  
Author(s):  
X. Fan ◽  
Z. Yu ◽  
J. Liu ◽  
N. Liu ◽  
K. A. Hajjar ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Annexin A2 ◽  
Stroke Therapy ◽  
Tissue Plasminogen

scholarly journals Annexin A2 acts as scaffolding receptor for plasminogen and tissue plasminogen activator in renal epithelia

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Henriette Josephine Kaminski ◽  
Christin Dathe ◽  
Hanna Neymeyer ◽  
Daniel Brand ◽  
Tanja Loof ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Annexin A2 ◽  
Renal Epithelia ◽  
Tissue Plasminogen

scholarly journals New transgenic evidence for a system of sympathetic axons able to express tissue plasminogen activator (t-PA) within arterial/arteriolar walls

Blood ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 200-202 ◽  
Author(s):  
Zhifang Hao ◽  
Caiying Guo ◽  
Xi Jiang ◽  
Susan Krueger ◽  
Thomas Pietri ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Chromaffin Cells ◽  
Fluorescent Protein ◽  
Sympathetic Neurons ◽  
Tissue Plasminogen ◽  
Confocal Images ◽  
Green Fluorescent ◽  
Adrenal Chromaffin ◽  
Ganglion Neurons

Sympathetic axons embedded in a few arterioles and vasa vasora were recently shown to store tissue plasminogen activator (t-PA) in vesicles. But the extension of such t-PA axons to arteries and arterioles throughout the organism has not been verified. Confirmation of this anatomy would identify a second significant source of vessel wall t-PA. To visualize fine embedded axons independent of endothelium, we created a transgenic mouse whose expressions of the t-PA promoter and enhanced green fluorescent protein are confined to sympathetic neurons and other neural crest derivatives. Confocal images reveal the extension of t-PA axons to arterioles serving heart, brain, kidney, lung, mesentery, and skin; plus aortic, carotid, and mesenteric artery walls. Ganglion neurons and adrenal chromaffin cells also show strong expressions. These new sightings confirm the existence of a system of t-PA axons that is prominent in arterioles, and compatible with the release of neural t-PA into their walls. (Blood. 2006;108:200-202)

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