scholarly journals Src family kinases-mediated negative regulation of sperm acrosome reaction in chickens (Gallus gallus domesticus)

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241181
Author(s):  
Chathura Priyadarshana ◽  
Rangga Setiawan ◽  
Atsushi Tajima ◽  
Atsushi Asano
Keyword(s):  
Acrosome Reaction ◽  
Tyrosine Phosphatase ◽  
Functional Characterization ◽  
Src Family Kinases ◽  
Prolonged Storage ◽  
Phosphatase Inhibitors ◽  
Calcium Dependent ◽  
Mammalian Sperm ◽  
Unique Mechanism

The acrosome reaction (AR) is a strictly-regulated, synchronous exocytosis that is required for sperm to penetrate ova. This all-or-nothing process occurs only once in the sperm lifecycle through a sequence of signaling pathways. Spontaneous, premature AR therefore compromises fertilization potential. Although protein kinase A (PKA) pathways play a central role in AR across species, the signaling network used for AR induction is poorly understood in birds. Mechanistic studies of mammalian sperm AR demonstrate that PKA activity is downstreamly regulated by Src family kinases (SFKs). Using SFK inhibitors, our study shows that in chicken sperm, SFKs play a role in the regulation of PKA activity and spontaneous AR without affecting motility. Furthermore, we examined the nature of SFK phosphorylation using PKA and protein tyrosine phosphatase inhibitors, which demonstrated that unlike in mammals, SFK phosphorylation in birds does not occur downstream of PKA and is primarily regulated by calcium-dependent tyrosine phosphatase activity. Functional characterization of SFKs in chicken sperm showed that SFK activation modulates the membrane potential and plays a role in inhibiting spontaneous AR. Employing biochemical isolation, we also found that membrane rafts are involved in the regulation of SFK phosphorylation. This study demonstrates a unique mechanism for regulating AR induction inherent to avian sperm that ensure fertilization potential despite prolonged storage.

scholarly journals A Microfluidics-Based Mobility Shift Assay to Discover New Tyrosine Phosphatase Inhibitors

2006 ◽  
Vol 11 (8) ◽  
pp. 996-1004 ◽  
Author(s):  
Dominique Perrin ◽  
Christèle Frémaux ◽  
Dominique Besson ◽  
Wolfgang HB Sauer ◽  
Alexander Scheer
Keyword(s):  
Drug Target ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Mobility Shift ◽  
Phosphatase Inhibitors ◽  
Mobility Shift Assay ◽  
Diabetes And Obesity ◽  
Major Drug ◽  
Specific Peptide

Protein tyrosine phosphatases (PTPs) play key roles in regulating tyrosine phosphorylation levels in cells. Since the discovery of PTP1B as a major drug target for diabetes and obesity, PTPs have emerged as a new and promising class of signaling targets for drug development in a variety of therapeutic areas. The routine use of generic substrate 6,8-difluoro-4-methylumbelliferyl phosphate (DiFMUP) in our hands led to the discovery of very similar and often not very selective molecules. Therefore, to increase the chances to discover novel chemical scaffolds, a side-by-side comparison between the DiFMUP assay and a chip-based mobility shift assay with a specific phosphopeptide was performed, on 1 PTP, using a focused set of compounds. Assay robustness and sensitivity were comparable for both the DiFMUP and mobility shift assays. The off-chip mobility shift assay required a longer development time because of identification, synthesis, and characterization of a specific peptide, and its cost per point was higher. However, although most potent scaffolds found with the DiFMUP assay were confirmed in the mobility shift format, the off-chip mobility shift assay led to the identification of previously unidentified chemical scaffolds with improved druglike properties.

scholarly journals Identification and functional characterization of p130Cas as a substrate of protein tyrosine phosphatase nonreceptor 14

Oncogene ◽  
2012 ◽  
Vol 32 (16) ◽  
pp. 2087-2095 ◽  
Author(s):  
P Zhang ◽  
A Guo ◽  
A Possemato ◽  
C Wang ◽  
L Beard ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Functional Characterization ◽  
Protein Tyrosine

scholarly journals Presence and Transmission of Mitochondrial Heteroplasmic Mutations in Human Populations of European and African Ancestry

2020 ◽  
Author(s):  
Chunyu Liu ◽  
Jessica L. Fetterman ◽  
Yong Qian ◽  
Xianbang Sun ◽  
Kaiyu Yan ◽  
...  
Keyword(s):  
Tyrosine Phosphatase ◽  
African Ancestry ◽  
Functional Characterization ◽  
Nuclear Genome ◽  
Human Populations ◽  
Sibling Pairs ◽  
Coding Regions ◽  
Genome Wide ◽  
A Genome

ABSTRACTWe investigated the concordance of mitochondrial DNA heteroplasmic mutations (heteroplasmies) in different types of maternal pairs (n=6,745 pairs) of European (EA, n=4,718 pairs) and African (AA, n=2,027 pairs) Americans with whole genome sequences (WGSs). The average concordance rate of heteroplasmies was highest between mother-offspring pairs, followed by sibling-sibling pairs and more distantly related maternal pairs in both EA and AA participants. The allele fractions of concordant heteroplasmies exhibited high correlation (R2=0.8) between paired individuals. Compared to concordant heteroplasmies, discordant ones were more likely to locate in coding regions, be nonsynonymous or nonsynonymous-deleterious (p<0.001). The average number of heteroplasmies per individual (i.e. heteroplasmic burden) was at a similar level until older age (70-80 years old) and increased significantly thereafter (p<0.01). The burden of deleterious heteroplasmies (combined annotation-dependent depletion score≥15), however, was significantly correlated with advancing age (20-44, 45-64, ≥65 years, p-trend=0.01). A genome-wide association analysis of the heteroplasmic burden identified many significant (P<5e-8) common variants (minor allele frequency>0.05) at 11p11.12. Many of the top SNPs act as strong long-range cis regulators of protein tyrosine phosphatase receptor type J. This study provides further evidence that mtDNA heteroplasmies may be inherited or somatic. Somatic heteroplasmic variants increase with advancing age and are more likely to have an adverse impact on mitochondrial function. Further studies are warranted for functional characterization of the deleterious heteroplasmies occurring with advancing age and the association of the 11p11.12 region of the nuclear genome with mtDNA heteroplasmy.

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