scholarly journals Rapid alteration of protein phosphorylation during postmortem: implication in the study of protein phosphorylation

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Yifan Wang ◽  
Yanchong Zhang ◽  
Wen Hu ◽  
Shutao Xie ◽  
Cheng-Xin Gong ◽  
...  
Keyword(s):  
Protein Phosphorylation ◽  
Glycogen Synthase ◽  
Post Translational Modification ◽  
Dependent Protein Kinase ◽  
Regular Time ◽  
Liver And Kidney ◽  
Dependent Protein ◽  
Gsk 3Β ◽  
Phosphate Buffered Saline ◽  
The Brain

Abstract Protein phosphorylation is an important post-translational modification of proteins. Postmortem tissues are widely being utilized in the biomedical studies, but the effects of postmortem on protein phosphorylation have not been received enough attention. In the present study, we found here that most proteins in mouse brain, heart, liver and kidney were rapidly dephosphorylated to various degrees during 20 sec to 10 min postmortem. Phosphorylation of tau at Thr212 and glycogen synthase kinase 3β (GSK-3β) at Ser9 was reduced by 50% in the brain with 40 sec postmortem, a regular time for tissue processing. During postmortem, phosphorylation of cAMP-dependent protein kinase (PKA) and AMP activated kinase (AMPK) was increased in the brain, but not in other organs. Perfusion of the brain with cold or room temperature phosphate-buffered saline (PBS) also caused significant alteration of protein phosphorylation. Cooling down and maintaining mouse brains in the ice-cold buffer prevented the alteration effectively. This study suggests that phosphorylation of proteins is rapidly changed during postmortem. Thus, immediate processing of tissues followed by cooling down in ice-cold buffer is vitally important and perfusion has to be avoided when protein phosphorylation is to be studied.

scholarly journals cGMP-dependent protein kinase II determines β-catenin accumulation that is essential for uterine decidualization in mice

2019 ◽  
Vol 317 (6) ◽  
pp. C1115-C1127
Author(s):  
Yang Zhang ◽  
Lu Yan ◽  
Jiali Liu ◽  
Sheng Cui ◽  
Jingtao Qiu
Keyword(s):  
Protein Kinase ◽  
Stromal Cells ◽  
Glycogen Synthase ◽  
Regulatory Function ◽  
Dependent Protein Kinase ◽  
Cgmp Dependent Protein Kinase ◽  
Decidual Cells ◽  
Proliferation And Differentiation ◽  
Dependent Protein ◽  
Gsk 3Β

In the early phase of pregnancy, decidualization is an indispensable event after mammal embryo implantation, accompanied by proliferation and differentiation of uterine stromal cells. Type II cGMP-dependent protein kinase (Prkg2) belongs to the family of serine/threonine kinase, which plays multiple roles in cellular signaling pathways to control proliferation and differentiation. However, the regulatory function and molecular mechanism of Prkg2 in decidualization are still unknown. In this study, we show that Prkg2 has a gradually increased expression pattern during peri-implantation and artificial decidualization, and the expression of Prkg2 is induced by estrogen and progesterone in the ovariectomized mouse uteri and primary cultured uterine stromal cells, the process of which is blocked by treating with estrogen receptor (ER) antagonist (ICI-182,780) and progesterone receptor (PR) antagonist (RU-486). Inhibition of Prkg2 activity by HA-100 promotes uterine stromal cell proliferation but compromises decidualization with decreased expression of prolactin family 8, subfamily a, member 2. In addition, the functional regulation of decidualization by Prkg2 is accomplished by its induced phosphorylation of glycogen synthase kinase-3β (GSK-3β) at serine-9, which results in accumulation of β-catenin in the decidual cells. Taken together, our findings demonstrate that estrogen and progesterone upregulate the expression of Prkg2 in uterine stromal cells depending on ER and PR; Prkg2 promotes phosphorylation of GSK-3β at serine-9 and inactivates it, leading to the accumulation of β-catenin and promoting the process of decidualization. In addition to revealing the regulatory mechanism of Prkg2 that ensures the success of uterine decidualization, our findings will contribute to the understanding in the maintenance of early pregnancy.

scholarly journals Activation State-Dependent Substrate Gating in Ca2+/Calmodulin-Dependent Protein Kinase II

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
D. E. Johnson ◽  
A. Hudmon
Keyword(s):  
Protein Kinase ◽  
Catalytic Domain ◽  
Intrinsic Property ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
State Dependent ◽  
Protein Kinase Ii ◽  
Dependent Protein ◽  
Substrate Phosphorylation ◽  
The Brain

Calcium/calmodulin-dependent protein kinase II (CaMKII) is highly concentrated in the brain where its activation by the Ca2+sensor CaM, multivalent structure, and complex autoregulatory features make it an ideal translator of Ca2+signals created by different patterns of neuronal activity. We provide direct evidence that graded levels of kinase activity and extent of T287(T286αisoform) autophosphorylation drive changes in catalytic output and substrate selectivity. The catalytic domains of CaMKII phosphorylate purified PSDs much more effectively when tethered together in the holoenzyme versus individual subunits. Using multisubstrate SPOT arrays, high-affinity substrates are preferentially phosphorylated with limited subunit activity per holoenzyme, whereas multiple subunits or maximal subunit activation is required for intermediate- and low-affinity, weak substrates, respectively. Using a monomeric form of CaMKII to control T287autophosphorylation, we demonstrate that increased Ca2+/CaM-dependent activity for all substrates tested, with the extent of weak, low-affinity substrate phosphorylation governed by the extent of T287autophosphorylation. Our data suggest T287autophosphorylation regulates substrate gating, an intrinsic property of the catalytic domain, which is amplified within the multivalent architecture of the CaMKII holoenzyme.

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