Characterisation and role of integrins during gametic interaction and egg activation

Zygote ◽  
1996 ◽  
Vol 4 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Céline de Nadai ◽  
Patrick Fenichel ◽  
Michèle Donzeau ◽  
David Epel ◽  
Brigitte Ciapa
Keyword(s):  
Sea Urchin ◽  
Cytoskeletal Proteins ◽  
Human Spermatozoa ◽  
Egg Activation ◽  
Western Blots ◽  
Sea Urchin Egg ◽  
Immunofluorescence Labelling ◽  
Β Chain

SummaryIt has recently been proposed that some of the processes induced by fertilisation in mammals may be mediated by integrins. By peforming immunofluorescence labelling and Western blots with antibodies directed against some of the α and β subunits of integrins, we show here the presence of some of these proteins in human and hamster oocytes. Among them, α2 and α5 were also present on in vitro preparations of sea urchin egg cortices. In addition, antibodies raised against these two proteins were the most effective at inhibiting attachment and fusion of human spermatozoa with hamster oocytes. We suggest that α2 and α5 integrin chains may be common mediators in adhesion-fusion mechanisms triggered by fertilisation. Using similar techniques, we show that eggs are rich three cytoskeletal proteins known to be linked to the β chain of integrins: talin, vinculin and α-actinin. Moreover, we found that talin and α-actinin were associated with proteins phosphorylated on tyrosine after fertilisation in sea urchin eggs. We suggest that integrins might be involved during fertilisation and trigger egg activation through cytoskeletal structures.

Abstract P780: Myosin Light Chain Dephosphorylation by Ppp1r12c Promotes Atrial Hypocontractility in Atrial Fibrillation

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Francisco J Gonzalez-Gonzalez ◽  
Perike Srikanth ◽  
Andrielle E Capote ◽  
Alsina Katherina M ◽  
Benjamin Levin ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Molecular Mechanisms ◽  
Contractile Function ◽  
Right Atrial ◽  
Western Blots

Atrial fibrillation (AF) is the most common sustained arrhythmia, with an estimated prevalence in the U.S.of 6.1 million. AF increases the risk of a thromboembolic stroke in five-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function in AF remains unknown. We have recently identified protein phosphatase 1 subunit 12c (PPP1R12C) as a key molecule targeting myosin light-chain phosphorylation in AF. Objective: We hypothesize that the overexpression of PPP1R12C causes hypophosphorylation of atrial myosin light-chain 2 (MLC2a), thereby decreasing atrial contractility in AF. Methods and Results: Left and right atrial appendage tissues were isolated from AF patients versus sinus rhythm (SR). To evaluate the role of the PP1c-PPP1R12C interaction in MLC2a de-phosphorylation, we utilized Western blots, co-immunoprecipitation, and phosphorylation assays. In patients with AF, PPP1R12C expression was increased 3.5-fold versus SR controls with an 88% reduction in MLC2a phosphorylation. PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF. In vitro studies of either pharmacologic (BDP5290) or genetic (T560A), PPP1R12C activation demonstrated increased PPP1R12C binding with both PP1c and MLC2a, and dephosphorylation of MLC2a. Additionally, to evaluate the role of PPP1R12C expression in cardiac function, mice with lentiviral cardiac-specific overexpression of PPP1R12C (Lenti-12C) were evaluated for atrial contractility using echocardiography, versus wild-type and Lenti-controls. Lenti-12C mice demonstrated a 150% increase in left atrium size versus controls, with reduced atrial strain and atrial ejection fraction. Also, programmed electrical stimulation was performed to evaluate AF inducibility in vivo. Pacing-induced AF in Lenti-12C mice was significantly higher than controls. Conclusion: The overexpression of PPP1R12C increases PP1c targeting to MLC2a and provokes dephosphorylation, associated with a reduction in atrial contractility and an increase in AF inducibility. All these discoveries suggest that PP1 regulation of sarcomere function at MLC2a is a main regulator of atrial contractility in AF.

Abstract P458: Myosin Light Chain Dephosphorylation By Ppp1r12c Promotes Atrial Hypocontractility In Atrial Fibrillation

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Francisco J Gonzalez-Gonzalez ◽  
Srikanth Perike ◽  
Frederick Damen ◽  
Andrielle Capote ◽  
Katherina M Alsina ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Molecular Mechanisms ◽  
Contractile Function ◽  
Right Atrial ◽  
Western Blots

Introduction: Atrial fibrillation (AF), is the most common sustained arrhythmia, with an estimated prevalence in the U.S. of 2.7 million to 6.1 million and is predictive to increase to 12.1 million in 2030. AF increases the chances of a thromboembolic stroke in five-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function in AF remains unknown. Objective: The overexpression of PPP1R12C, causes hypophosphorylation of atrial myosin light chain 2 (MLC2a), decreasing atrial contractility. Methods and Results: Left and right atrial appendage tissues were isolated from AF patients versus sinus rhythm (SR). To evaluated the role of PP1c-PPP1R12C interaction in MLC2a de-phosphorylation we used Western blots, coimmunoprecipitation, and phosphorylation assays. In patients with AF, PPP1R12C expression was increased 3.5-fold versus SR controls with an 88% reduction in MLC2a phosphorylation. PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF. In vitro studies of either pharmacologic (BDP5290) or genetic (T560A) PPP1R12C activation demonstrated increased PPP1R12C binding with both PP1c and MLC2a, and dephosphorylation of MLC2a. Additionally, to evaluate the role of PPP1R12C expression in cardiac function, mice with lentiviral cardiac-specific overexpression of PPP1R12C (Lenti-12C) were evaluated for atrial contractility using echocardiography, versus wild-type and Lenti-controls. Lenti-12C mice demonstrated a 150% increase in left atrium size versus controls, with reduced atrial strain and atrial ejection fraction. Also, programmed electrical stimulation was performed to evaluate AF inducibility in vivo. Pacing-induced AF in Lenti-12C mice was significantly higher than controls. Conclusion: The Overexpression of PPP1R12C increases PP1c targeting to MLC2a and provokes dephosphorylation, that cause a reduction in atrial contractility and increases AF inducibility. All these discoveries advocate that PP1 regulation of sarcomere function at MLC2a is a main regulator of atrial contractility in AF.

scholarly journals IN VITRO FERTILITY TEST OF HUMAN SPERMATOZOA MEMBRANE PROTEIN FERTILIN BETA ANTIBODY IN MICE (Mus musculus Balb/c) AS IMMUNOCONTRACEPTIVE CANDIDATE

2017 ◽  
Vol 52 (3) ◽  
pp. 209
Author(s):  
Reny I’tishom ◽  
Doddy M Soebadi ◽  
Aucky Hinting ◽  
Hamdani Lunardhi ◽  
Rina Yudiwati
Keyword(s):  
In Vitro Fertilization ◽  
Membrane Protein ◽  
Mus Musculus ◽  
Human Spermatozoa ◽  
Control Group ◽  
Reproductive Process ◽  
Vitro Fertilization ◽  
Antibody Induction

One of the materials as potential candidates immunocontraception material is spermatozoa. Fertilin beta is spermatozoa membrane protein and is found only in mature spermatozoa and ejaculate, which serves as an adhesion molecule. Spermatozoa membrane protein that is used as an ingredient immunocontraception candidate, must have specific criteria that the specificity of spermatozoa, the role of antigen in the fertilization process, which includes the formation of immunogenicity sufficient antibody response has the potential to block fertilization. Antibodies against spermatozoa affect the stages before fertilization of the reproductive process and can hinder the development of the embryo after fertilization. Until now very little research data spermatozoa membrane protein as an ingredient immunocontraception are up to the test of experimental animals. The research objective is to prove the role of the resulting antibody induction of antibodies fertilin beta protein in the membrane of human spermatozoa induce agglutination and reduce motility thus reducing the number of in vitro fertilization. Research conducted at the IVF Laboratory, Department of Biology of Medicine, Faculty of Medicine, University of Airlangga. This research includes: Test the potential of antibody protein beta fertilin membrane of human spermatozoa and inhibit the role of antibodies in vitro fertilization in mice (Mus musculus Balb/c). In vitro studies have resulted in fertilization figure of 25% is smaller than the number that is equal to control fertilization of 58.7%, whereas previously the spermatozoa were incubated first with a beta membrane protein antibody fertilin human spermatozoa. While the percentage of inhibition of sperm to fertilize an oocyte by 33.75%. Potential imunokontraseptif considered effective if it decreased significantly (P <0.05) than the numbers fertilization in the treatment group compared with the control group. This shows fertilin beta membrane protein antibody has the ability to inhibit human spermatozoa to fertilize oocytes that reduce the number of fertilization.

scholarly journals Role of cytoskeletal proteins in cerebral cavernous malformation signaling pathways: a proteomic analysis

2014 ◽  
Vol 10 (7) ◽  
pp. 1881-1889 ◽  
Author(s):  
Sarah Schwartz Baxter ◽  
Christopher F. Dibble ◽  
Warren C. Byrd ◽  
Jim Carlson ◽  
Charles Russell Mack ◽  
...  
Keyword(s):  
Systems Biology ◽  
Signaling Pathways ◽  
Proteomic Analysis ◽  
Cavernous Malformation ◽  
Cytoskeletal Proteins ◽  
Cerebral Cavernous Malformation

Anin vitroproteomics and systems biology of cerebral cavernous malformation.

Ryanodine Activates Sea Urchin Eggs. (sea urchin egg/activation/ryanodine/inositol phosphate/heparin)

1992 ◽  
Vol 34 (1) ◽  
pp. 37-42 ◽  
Author(s):  
C. Sardet ◽  
I. Gillot ◽  
A. Ruscher ◽  
P. Payan ◽  
J.-P. Girard ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Inositol Phosphate ◽  
Egg Activation ◽  
Sea Urchin Eggs ◽  
Sea Urchin Egg

scholarly journals Impaired FcϵRI stability, signaling, and effector functions in murine mast cells lacking glycosylphosphatidylinositol-anchored proteins

Blood ◽  
2011 ◽  
Vol 118 (16) ◽  
pp. 4377-4383 ◽  
Author(s):  
Wouter L. W. Hazenbos ◽  
Ping Wu ◽  
Jeffrey Eastham-Anderson ◽  
Taroh Kinoshita ◽  
Eric J. Brown
Keyword(s):  
Mast Cells ◽  
Targeted Disruption ◽  
Potential Therapeutic Target ◽  
Effector Functions ◽  
Ige Mediated ◽  
Interchain Interactions ◽  
Β Chain ◽  
Stimulation Of

Abstract A key event and potential therapeutic target in allergic and asthmatic diseases is signaling by the IgE receptor FcϵRI, which depends on its interactions with Src family kinases (SFK). Here we tested the hypothesis that glycosylphosphatidylinositiol-anchored proteins (GPI-AP) are involved in FcϵRI signaling, based on previous observations that GPI-AP colocalize with and mediate activation of SFK. We generated mice with a hematopoietic cell-specific GPI-AP deficiency by targeted disruption of the GPI biosynthesis gene PigA. In these mice, IgE-mediated passive cutaneous anaphylaxis was largely abolished. PigA-deficient mast cells cultured from these mice showed impaired degranulation in response to stimulation with IgE and antigen in vitro, despite normal IgE binding and antigen-induced FcϵRI aggregation. On stimulation of these cells with IgE and antigen, coprecipitation of the FcϵRI α-chain with the γ-chain and β-chain was markedly reduced. As a result, IgE/antigen–induced FcϵRI-Lyn association and γ-chain tyrosine phosphorylation were both impaired in PigA-deficient cells. These data provide genetic evidence for an unanticipated key role of GPI-AP in FcϵRI interchain interactions and early FcϵRI signaling events, necessary for antigen-induced mast cell degranulation.

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