scholarly journals Fibronectin stimulates human sperm capacitation through the cyclic AMP/protein kinase A pathway

2015 ◽  
Vol 30 (9) ◽  
pp. 2138-2151 ◽  
Author(s):  
E. Martínez-León ◽  
C. Osycka-Salut ◽  
J. Signorelli ◽  
P. Pozo ◽  
B. Pérez ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinase A ◽  
Human Sperm ◽  
Sperm Capacitation ◽  
Kinase A

scholarly journals The activation of the chymotrypsin-like activity of the proteasome is regulated by soluble adenyl cyclase/cAMP/protein kinase A pathway and required for human sperm capacitation

2019 ◽  
Vol 25 (10) ◽  
pp. 587-600 ◽  
Author(s):  
Héctor Zapata-Carmona ◽  
Lina Barón ◽  
Lidia M Zuñiga ◽  
Emilce Silvina Díaz ◽  
Milene Kong ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Current Knowledge ◽  
Human Sperm ◽  
Adenyl Cyclase ◽  
Sperm Capacitation ◽  
Time Treatment ◽  
Proteasome Subunits ◽  
Pka Pathway ◽  
Kinase A

Abstract One of the first events of mammalian sperm capacitation is the activation of the soluble adenyl cyclase/cAMP/protein kinase A (SACY/cAMP/PKA) pathway. Here, we evaluated whether the increase in PKA activity at the onset of human sperm capacitation is responsible for the activation of the sperm proteasome and whether this activation is required for capacitation progress. Viable human sperm were incubated with inhibitors of the SACY/cAMP/PKA pathway. The chymotrypsin-like activity of the sperm proteasome was evaluated using a fluorogenic substrate. Sperm capacitation status was evaluated using the chlortetracycline assay and tyrosine phosphorylation. To determine whether proteasomal subunits were phosphorylated by PKA, the proteasome was immunoprecipitated and tested on a western blot using an antibody against phosphorylated PKA substrates. Immunofluorescence microscopy analysis and co-immunoprecipitation (IPP) were used to investigate an association between the catalytic subunit alpha of PKA (PKA-Cα) and the proteasome. The chymotrypsin-like activity of the sperm proteasome significantly increased after 5 min of capacitation (P < 0.001) and remained high for the remaining incubation time. Treatment with H89, KT5720 or KH7 significantly decreased the chymotrypsin-like activity of the proteasome (P < 0.001). IPP experiments indicated that PKA inhibition significantly modified phosphorylation of proteasome subunits. In addition, PKA-Cα colocalized with the proteasome in the equatorial segment and in the connecting piece, and co-immunoprecipitated with the proteasome. This is the first demonstration of sperm proteasome activity being directly regulated by SACY/PKA-Cα. This novel discovery extends our current knowledge of sperm physiology and may be used to manage sperm capacitation during assisted reproductive technology procedures.

Interaction Between Protein Kinase A (PKA) and Protein Phosphatase PP2A During Human Sperm Capacitation.

2012 ◽  
Vol 87 (Suppl_1) ◽  
pp. 448-448
Author(s):  
Patricio J. Morales ◽  
Kely Ordenes ◽  
Lidia Zuñiga ◽  
Emilce S. Diaz
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein Phosphatase ◽  
Human Sperm ◽  
Sperm Capacitation ◽  
Kinase A

Protein Kinase A modulation by nitric oxide during human sperm capacitation

2018 ◽  
Author(s):  
Florentin-Daniel Staicu ◽  
CARMEN MATAS PARRA ◽  
Juan Carlos Martínez Soto
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Human Sperm ◽  
Sperm Capacitation ◽  
Kinase A

scholarly journals Protein Kinase A (PRKA) Activity Is Regulated by the Proteasome at the Onset of Human Sperm Capacitation

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3501
Author(s):  
Héctor Zapata-Carmona ◽  
Lina Barón ◽  
Milene Kong ◽  
Patricio Morales
Keyword(s):  
Protein Kinase ◽  
Western Blot ◽  
Protein Kinase A ◽  
Human Sperm ◽  
Sperm Capacitation ◽  
Phosphorylation Pattern ◽  
Presence And Absence ◽  
Kinase A

The proteasome increases its activity at the onset of sperm capacitation due to the action of the SACY/PRKACA pathway; this increase is required for capacitation to progress. PRKA activity also increases and remains high during capacitation. However, intracellular levels of cAMP decrease in this process. Our goal was to evaluate the role of the proteasome in regulating PRKA activity once capacitation has started. Viable human sperm were incubated in the presence and absence of epoxomicin or with 0.1% DMSO. The activity of PRKA; the phosphorylation pattern of PRKA substrates (pPRKAs); and the expression of PRKAR1, PRKAR2, and AKAP3 were evaluated by Western blot. The localization of pPRKAs, PRKAR1, PRKAR2, and AKAP3 was evaluated by immunofluorescence. Treatment with epoxomicin changed the localization and phosphorylation pattern and decreased the percentage of pPRKAs-positive sperm. PRKA activity significantly increased at 1 min of capacitation and remained high throughout the incubation. However, epoxomicin treatment significantly decreased PRKA activity after 30 min. In addition, PRKAR1 and AKAP3 were degraded by the proteasome but with a different temporal kinetic. Our results suggest that PRKAR1 is the target of PRKA regulation by the proteasome.

scholarly journals Evidence that glucocorticoid- and cyclic AMP-induced apoptotic pathways in lymphocytes share distal events

1992 ◽  
Vol 12 (8) ◽  
pp. 3600-3608
Author(s):  
D R Dowd ◽  
R L Miesfeld
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinase A ◽  
Protein Product ◽  
Single Step ◽  
Mitochondrial Activity ◽  
Isolation And Characterization ◽  
Resistant Phenotype ◽  
Apoptotic Pathways ◽  
Kinase A

WEHI7.2 murine lymphocytes undergo apoptotic death when exposed to glucocorticoids or elevated levels of intracellular cyclic AMP (cAMP), and these pathways are initiated by the glucocorticoid receptor (GR) and protein kinase A, respectively. We report the isolation and characterization of a novel WEHI7.2 variant cell line, WR256, which was selected in a single step for growth in the presence of dexamethasone and arose at a frequency of approximately 10(-10). The defect was not GR-related, as WR256 expressed functional GR and underwent GR-dependent events associated with apoptosis, such as hormone-dependent gene transcription and inhibition of cell proliferation. Moreover, the glucocorticoid-resistant phenotype was stable in culture and did not revert after treatment with 5-azacytidine or upon stable expression of GR cDNA. In addition, WR256 did not exhibit the diminished mitochondrial activity commonly associated with apoptosis. Interestingly, WR256 was also found to be resistant to 8-bromo-cAMP and forskolin despite having normal levels of protein kinase A activity and the ability to induce cAMP-dependent transcription. We examined the steady-state transcript levels of bcl-2, a gene whose protein product acts dominantly to inhibit thymocyte apoptosis, to determine whether elevated bcl-2 expression could account for the resistant phenotype. Our data showed that bcl-2 RNA levels were similar in the two cell lines and not altered by either dexamethasone or 8-bromo-cAMP treatment. These results suggest that WR256 exhibits a "deathless" phenotype and has a unique defect in a step of the apoptotic cascade that may be common to the glucocorticoid- and cAMP-mediated cell death pathways.

scholarly journals Terbutaline, forskolin and cAMP reduce secretion of aqueous humour in the isolated bovine eye

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244253
Author(s):  
Mohammad Shahidullah ◽  
William Stuart Wilson ◽  
Kazi Rafiq ◽  
Mahmudul Hasan Sikder ◽  
Jannatul Ferdous ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinase A ◽  
Aqueous Humour ◽  
Calcium Release ◽  
Drug Effects ◽  
Inhibitory Effect ◽  
Plateau Phase ◽  
Intracellular Ca ◽  
Kinase A

In order to elucidate involvement of cyclic AMP and intracellular Ca2+,[Ca2+]i, in the modulation of aqueous humour formation (AHF), we studied the effects of terbutaline, forskolin and 8-Br-cAMP in the isolated bovine eye. We also studied the interaction of cAMP on calcium signaling in cultured ciliary epithelial (CE) cells. Drug effects on AHF were measured by fluorescein dilution. Drug effects on [Ca2+]i were studied by the fura-2 fluorescence ratio technique. Terbutaline (100 nmol-100 M), forskolin (30 nM-100 M) or 8-Br-cAMP (100 nM– 10 μM), administered in the arterial perfusate produced significant reductions in AHF. The AH reducing effect of terbutaline was blocked by a selective inhibitor of protein kinase A (KT-5720). ATP (100 M) caused a rapid, transient (peak) increase in [Ca2+]i followed by a sustained plateau phase lasting more than 5 minutes. Preincubation of the cells (6 min) with terbutaline, forskolin or 8-Br-cAMP significantly reduced the peak calcium response to ATP. The sustained plateau phase of the response, on the other hand, was augmented by each of the agents. KT-5720 partially reversed the inhibitory effect of terbutaline on the peak and totally inhibited its effect on the plateau phase. These data indicate: (a) that AHF in the bovine eye can be manipulated through cyclic AMP, operating via protein kinase A, (b) that protein kinase A can affect [Ca2+]i homeostasis, (c) that calcium release from the intracellular store, not the entry, affects AHF, and (d) that interaction of [Ca2+]i with cAMP plays a role in modulating AH secretion.

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