scholarly journals SNAP23 is required for constitutive and regulated exocytosis in mouse oocytes†

2019 ◽  
Vol 101 (2) ◽  
pp. 338-346 ◽  
Author(s):  
Lisa M Mehlmann ◽  
Tracy F Uliasz ◽  
Katie M Lowther
Keyword(s):  
Plasma Membranes ◽  
Follicle Cells ◽  
Cortical Granule ◽  
Membrane Turnover ◽  
Meiotic Arrest ◽  
Regulated Exocytosis ◽  
Mouse Oocytes ◽  
Lectin Staining ◽  
Gap Junction Communication ◽  
Cortical Granule Exocytosis

Abstract Mammalian oocytes are stored in the ovary for prolonged periods, and arrested in meiotic prophase. During this period, their plasma membranes are constantly being recycled by endocytosis and exocytosis. However, the function of this membrane turnover is unknown. Here, we investigated the requirement for exocytosis in the maintenance of meiotic arrest. Using Trim-away, a newly developed method for rapidly and specifically depleting proteins in oocytes, we have identified the SNARE protein, SNAP23, to be required for meiotic arrest. Degradation of SNAP23 causes premature meiotic resumption in follicle-enclosed oocytes. The reduction in SNAP23 is associated with loss of gap junction communication between the oocyte and surrounding follicle cells. Reduction of SNAP23 protein also inhibits regulated exocytosis in response to a Ca2+ stimulus (cortical granule exocytosis), as measured by lectin staining and cleavage of ZP2. Our results show an essential role for SNAP23 in two key processes that occur in mouse oocytes and eggs.

scholarly journals SNAP23 is required for the maintenance of meiotic arrest and cortical granule exocytosis in mouse oocytes

2019 ◽  
Author(s):  
Lisa M. Mehlmann ◽  
Tracy F. Uliasz ◽  
Katie M. Lowther
Keyword(s):  
Gap Junction ◽  
Plasma Membranes ◽  
Follicle Cells ◽  
Cortical Granule ◽  
Snare Protein ◽  
Meiotic Arrest ◽  
Granule Exocytosis ◽  
Mouse Oocytes ◽  
Gap Junction Communication ◽  
Cortical Granule Exocytosis

ABSTRACTMammalian oocytes are stored in the ovary for prolonged periods, arrested in meiotic prophase. During this period, their plasma membranes are constantly being recycled by endocytosis and exocytosis. However, the function of this membrane turnover is unknown. Here, we investigated the requirement for exocytosis in the maintenance of meiotic arrest. Using a newly developed method for rapidly and specifically depleting proteins in oocytes, we have identified the SNARE protein, SNAP23, to be required for meiotic arrest. Degradation of SNAP23 causes premature meiotic resumption in follicle-enclosed oocytes. The reduction in SNAP23 is associated with loss of gap junction communication between the oocyte and surrounding follicle cells. Reduction of SNAP23 protein also inhibits cortical granule exocytosis in response to a Ca2+ stimulus, as measured by lectin staining and cleavage of ZP2. Our results show an essential role for SNAP23 in two key processes that occur in mouse oocytes and eggs.SummaryThe SNARE protein, SNAP23, is required to maintain gap junction communication between the oocyte and follicle cells that is needed to maintain oocyte meiotic arrest, as well as for cortical granule exocytosis at fertilization.

scholarly journals Cortical Granule Exocytosis Is Mediated by Alpha-SNAP and N-Ethilmaleimide Sensitive Factor in Mouse Oocytes

PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0135679 ◽  
Author(s):  
Matilde de Paola ◽  
Oscar Daniel Bello ◽  
Marcela Alejandra Michaut
Keyword(s):  
Cortical Granule ◽  
Granule Exocytosis ◽  
Mouse Oocytes ◽  
Sensitive Factor ◽  
Cortical Granule Exocytosis

Mouse oocytes penetrated by sperm at GV or GVBD stage lose the ablity to fuse with additional spermatozoa

Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Beata Pyrzyńska ◽  
M. Maleszewski ◽  
D. Maluchnik
Keyword(s):  
Plasma Membrane ◽  
Meiotic Division ◽  
Germinal Vesicle ◽  
Cortical Granule ◽  
Dibutyryl Camp ◽  
Granule Exocytosis ◽  
Mouse Oocytes ◽  
Sperm Nuclei ◽  
Cortical Granule Exocytosis

SummaryMouse oocytes penetrated by spermatozoa during germinal vesicle (GV) breakdown undergo maturation and are arrested at metaphase of the second meiotic division despite the presence of sperm nuclei within the ooplasm. When these oocytes were re-inseminated, none was penetrated by newly added spermatozoa. When GV oocytes were inseminated and cultured in the presence of dibutyryl cAMP, the oocytes remained at GV stage, yet they did not permit entry of additional spermatozoa. These observations suggest that the plasma membrane of maturing oocytes is modified by precociously penetrating spermatozoa independently from cortical granule exocytosis. Sperm components incorporated into the oocytes seem to be responsible for the modification of the oocyte's plasma membrane.

scholarly journals Comparison of quick-frozen and chemically fixed sea-urchin eggs: structural evidence that cortical granule exocytosis is preceded by a local increase in membrane mobility

1984 ◽  
Vol 72 (1) ◽  
pp. 23-36 ◽  
Author(s):  
D.E. Chandler
Keyword(s):  
Sea Urchin ◽  
Large Scale ◽  
Osmium Tetroxide ◽  
Plasma Membranes ◽  
Strongylocentrotus Purpuratus ◽  
Cortical Granule ◽  
Granule Exocytosis ◽  
Purple Sea Urchin ◽  
Membrane Blebs ◽  
Cortical Granule Exocytosis

Eggs of the purple sea-urchin, Strongylocentrotus purpuratus, were fertilized and fixed with 2% glutaraldehyde at various stages during cortical granule exocytosis. Fixation resulted in membrane blebs being formed precisely at the point of incipient granule fusion. These blebs pinched off to form the membranous vesicles frequently seen in exocytic pockets and in the perivitelline space. In contrast, eggs that were fixed with osmium tetroxide or were quick-frozen without chemical fixation, showed no signs of bleb or vesicle formation. Rather, fusion of each granule appeared to begin at a single minute pore, 30–50 nm in diameter, which then enlarged. We suggest that formation of blebs during glutaraldehyde fixation is an artifact that is caused by a highly localized and transient increase in membrane mobility. Normally, this increased mobility facilitates fusion of granule and plasma membranes, but in the presence of glutaraldehyde it leads to large-scale distortions of these fusing membranes.

VAMPs sensitive to tetanus toxin are required for cortical granule exocytosis in mouse oocytes

2021 ◽  
pp. 112629
Author(s):  
Matilde de PAOLA ◽  
Facundo GARRIDO ◽  
María N. ZANETTI ◽  
Marcela Alejandra MICHAUT
Keyword(s):  
Tetanus Toxin ◽  
Cortical Granule ◽  
Granule Exocytosis ◽  
Mouse Oocytes ◽  
Cortical Granule Exocytosis

scholarly journals Activators of protein kinase C trigger cortical granule exocytosis, cortical contraction, and cleavage furrow formation in Xenopus laevis oocytes and eggs.

1989 ◽  
Vol 108 (3) ◽  
pp. 885-892 ◽  
Author(s):  
W M Bement ◽  
D G Capco
Keyword(s):  
Protein Kinase C ◽  
Retinoic Acid ◽  
Protein Kinase ◽  
Xenopus Laevis ◽  
Follicle Cells ◽  
Cortical Granule ◽  
Cleavage Furrow ◽  
Granule Exocytosis ◽  
Kinase C ◽  
Cortical Granule Exocytosis

Prophase I oocytes, free of follicle cells, and metaphase II eggs of the amphibian Xenopus laevis were subjected to transient treatments with the protein kinase C activators, phorbol 12-myristate 13-acetate (PMA), phorbol 12,13-didecanoate, and 1-olyeoyl-2-acetyl-sn-glycerol. In both oocytes and eggs, these treatments triggered early events of amphibian development: cortical granule exocytosis, cortical contraction, and cleavage furrow formation. Surprisingly, activation of oocytes occurred in the absence of meiotic resumption, resulting in cells with an oocytelike nucleus and interior cytoplasm, but with a zygotelike cortex. PMA-induced activation of oocytes and eggs did not require external calcium, a prerequisite for normal activation of eggs. PMA-induced activation of eggs was inhibited by retinoic acid, a known inhibitor of protein kinase C. In addition, pretreatment of eggs with retinoic acid prevented activation by mechanical stimulation and inhibited activation by calcium ionophore A23187. The results suggest that protein kinase C activation is an integral component of the Xenopus fertilization pathway.

scholarly journals Live imaging of cortical granule exocytosis reveals that in vitro matured mouse oocytes are not fully competent to secrete their content

Biology Open ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. bio031872 ◽  
Author(s):  
Andrea I. Cappa ◽  
Matilde de Paola ◽  
Paula Wetten ◽  
Gerardo A. De Blas ◽  
Marcela A. Michaut
Keyword(s):  
Live Imaging ◽  
Cortical Granule ◽  
Granule Exocytosis ◽  
Mouse Oocytes ◽  
Cortical Granule Exocytosis
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