Chronic stress affects tyrosine phosphorylated protein expression and secretion of male rat epididymis

Abstract Platelet functions such as aggregation and clot retraction are often abnormal in chronic mylogenous leukemia (CML) patients. However, the molecular mechanisms of these altered functions are unknown. As expression of the p210bcr-abl oncogene product, a constitutively active tyrosine kinase, is known to have an essential role in the pathogenesis of CML and tyrosine phosphorylation is intimately involved in various aspects of platelet activation, we examined the pattern of protein tyrosine phosphorylation in platelets from 15 CML patients by immunoblotting with a monoclonal antiphosphotyrosine antibody (4G10). Before and after stimulation with thrombin, the only consistent difference between normal and CML platelets was the presence of a tyrosine phosphorylated protein with a relative molecular weight of 39 kD. This tyrosine phosphorylated protein was identified as crid, an SH2, SH3 containing adapter protein. Thus, as previously demonstrated for neutrophils from CML patients, tyrosine phosphorylation of p39crkl persists in mature platelets. No tyrosine phosphorylation of crid was detected following stimulation with thrombin in normal platelets. However, crkl became incorporated into the Triton X-100 insoluble residue following thrombin stimulation in a manner dependent on platelet aggregation. Further, we found that crkl is an endogenous substrate for calpain, a protease that may be involved in postaggregation signaling processes. This suggests that crkl may be involved in the reorganization of the cytoskeleton during normal platelet aggregation and its tyrosine phosphorylation in CML platelets may contribute to the abnormal platelet function in CML patients. Finally, we found that thrombopoietin induces tyrosine phosphorylation of crk1 in normal platelets and FDCP cells genetically engineered to express human c-Mpl. This suggests that crk1 can be phosphorylated by a kinase other than p210bcr-abl and that crk1 may have a role in signaling by thrombopoietin.

Download Full-text

Identification of the major tyrosine phosphorylated protein of capacitated hamster spermatozoa as a homologue of mammalian sperm a kinase anchoring protein

Molecular Reproduction and Development ◽

10.1002/mrd.1155 ◽

2002 ◽

Vol 61 (2) ◽

pp. 258-270 ◽

Cited By ~ 36

Author(s):

Kula Nand Jha ◽

S. Shivaji

Keyword(s):

Phosphorylated Protein ◽

Mammalian Sperm ◽

Anchoring Protein ◽

Tyrosine Phosphorylated Protein

Download Full-text

Correction: The Chlamydia trachomatis Type III Secretion Chaperone Slc1 Engages Multiple Early Effectors, Including TepP, a Tyrosine-phosphorylated Protein Required for the Recruitment of CrkI-II to Nascent Inclusions and Innate Immune Signaling

PLoS Pathogens ◽

10.1371/journal.ppat.1004094 ◽

2014 ◽

Vol 10 (3) ◽

pp. e1004094

Author(s):

Keyword(s):

Chlamydia Trachomatis ◽

Type Iii Secretion ◽

Innate Immune ◽

Immune Signaling ◽

Phosphorylated Protein ◽

Type Iii ◽

Innate Immune Signaling ◽

Tyrosine Phosphorylated Protein ◽

Secretion Chaperone

Download Full-text

Characterization of GABAergic Marker Expression in the Chronic Unpredictable Stress Model of Depression

Chronic Stress ◽

10.1177/2470547017720459 ◽

2017 ◽

Vol 1 ◽

pp. 247054701772045 ◽

Cited By ~ 32

Author(s):

Mounira Banasr ◽

Ashley Lepack ◽

Corey Fee ◽

Vanja Duric ◽

Jaime Maldonado-Aviles ◽

...

Keyword(s):

Major Depressive Disorder ◽

Prefrontal Cortex ◽

Depressive Disorder ◽

Protein Expression ◽

Neuropeptide Y ◽

Chronic Stress ◽

Gabaergic Interneurons ◽

Chronic Unpredictable Stress ◽

Major Depressive

Background Evidence continues to build suggesting that the GABAergic neurotransmitter system is altered in brains of patients with major depressive disorder. However, there is little information available related to the extent of these changes or the potential mechanisms associated with these alterations. As stress is a well-established precipitant to depressive episodes, we sought to explore the impact of chronic stress on GABAergic interneurons. Methods Using western blot analyses and quantitative real-time polymerase chain reaction, we assessed the effects of five-weeks of chronic unpredictable stress exposure on the expression of GABA-synthesizing enzymes (GAD65 and GAD67), calcium-binding proteins (calbindin, parvalbumin, and calretinin), and neuropeptides co-expressed in GABAergic neurons (somatostatin, neuropeptide Y, vasoactive intestinal peptide, and cholecystokinin) in the prefrontal cortex and hippocampus of rats. We also investigated the effects of corticosterone and dexamethasone exposure on these markers in vitro in primary cortical and hippocampal cultures. Results We found that chronic unpredictable stress induced significant reductions of GAD67 protein levels in both the prefrontal cortex and hippocampus of chronic unpredictable stress-exposed rats but did not detect changes in GAD65 protein expression. Similar protein expression changes were found in vitro in cortical neurons. In addition, our results provide clear evidence of reduced markers of interneuron population(s), namely somatostatin and neuropeptide Y, in the prefrontal cortex, suggesting these cell types may be selectively vulnerable to chronic stress. Conclusion Together, this work highlights that chronic stress induces regional and cell type-selective effects on GABAergic interneurons in rats. These findings provide additional supporting evidence that stress-induced GABA neuron dysfunction and cell vulnerability play critical roles in the pathophysiology of stress-related illnesses, including major depressive disorder.

Download Full-text