scholarly journals Site-Specific Phosphorylation Induces Functionally Active Conformation in the Intrinsically Disordered N-Terminal Activation Function (AF1) Domain of the Glucocorticoid Receptor

2009 ◽  
Vol 30 (1) ◽  
pp. 220-230 ◽  
Author(s):  
Anna M. S. Garza ◽  
Shagufta H. Khan ◽  
Raj Kumar
Keyword(s):  
Glucocorticoid Receptor ◽  
Tertiary Structure ◽  
Steroid Receptors ◽  
Activation Function ◽  
Mitogen Activated Protein Kinase ◽  
Active Conformation ◽  
Activation Domain ◽  
Site Specific ◽  
Intrinsically Disordered ◽  
Mitogen Activated Protein

ABSTRACT Intrinsically disordered (ID) regions are disproportionately higher in cell signaling proteins and are predicted to have much larger frequency of phosphorylation sites than ordered regions, suggesting an important role in their regulatory capacity. In this study, we show that AF1, an ID activation domain of the glucocorticoid receptor (GR), adopts a functionally folded conformation due to its site-specific phosphorylation by p38 mitogen-activated protein kinase, which is involved in apoptotic and gene-inductive events initiated by the GR. Further, we show that site-specific phosphorylation-induced secondary and tertiary structure formation specifically facilitates AF1's interaction with critical coregulatory proteins and subsequently its transcriptional activity. These data demonstrate a mechanism through which ID activation domain of the steroid receptors and other similar transcription factors may adopt a functionally active conformation under physiological conditions.

scholarly journals Molecular Modeling of Differentially Phosphorylated Serine 10 and Acetylated lysine 9/14 of Histone H3 Regulates their Interactions with 14-3-3ζ, MSK1, and MKP1

2013 ◽  
Vol 7 ◽  
pp. BBI.S12449 ◽  
Author(s):  
Ajit K. Sharma ◽  
Abhilasha Mansukh ◽  
Ashok Varma ◽  
Nikhil Gadewal ◽  
Sanjay Gupta
Keyword(s):  
Molecular Modeling ◽  
Protein Kinase ◽  
Chromatin Structure ◽  
In Silico ◽  
Association Studies ◽  
Regulatory Proteins ◽  
Mitogen Activated Protein Kinase ◽  
Site Specific ◽  
Mitogen Activated Protein ◽  
Neighboring Site

Histone modifications occur in precise patterns, with several modifications known to affect the binding of proteins. These interactions affect the chromatin structure, gene regulation, and cell cycle events. The dual modifications on the H3 tail, serine10 phosphorylation, and lysine14 acetylation (H3Ser10PLys14Ac) are reported to be crucial for interaction with 14-3-3ζ. However, the mechanism by which H3Ser10P along with neighboring site-specific acetylation(s) is targeted by its regulatory proteins, including kinase and phosphatase, is not fully understood. We carried out molecular modeling studies to understand the interaction of 14-3-3ζ, and its regulatory proteins, mitogen-activated protein kinase phosphatase-1 (MKP1), and mitogen- and stress-activated protein kinase-1 (MSK1) with phosphorylated H3Ser10 alone or in combination with acetylated H3Lys9 and Lys14. In silico molecular association studies suggested that acetylated Lys14 and phosphorylated Ser10 of H3 shows the highest binding affinity towards 14-3-3ζ. In addition, acetylation of H3Lys9 along with Ser10PLys14Ac favors the interaction of the phosphatase, MKP1, for dephosphorylation of H3Ser10P. Further, MAP kinase, MSK1 phosphorylates the unmodified H3Ser10 containing N-terminal tail with maximum affinity compared to the N-terminal tail with H3Lys9AcLys14Ac. The data clearly suggest that opposing enzymatic activity of MSK1 and MKP1 corroborates with non-acetylated and acetylated, H3Lys9Lys14, respectively. Our in silico data highlights that site-specific phosphorylation (H3Ser10P) and acetylation (H3Lys9 and H3Lys14) of H3 are essential for the interaction with their regulatory proteins (MKP1, MSK1, and 14-3-3ζ) and plays a major role in the regulation of chromatin structure.

scholarly journals Novel Antidepressant-Like Activity of Caffeic Acid Phenethyl Ester Is Mediated by Enhanced Glucocorticoid Receptor Function in the Hippocampus

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mi-Sook Lee ◽  
Young Han Kim ◽  
Bo-ram Lee ◽  
Seung-Hae Kwon ◽  
Won-Jin Moon ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Caffeic Acid ◽  
Behavioral Assessment ◽  
Caffeic Acid Phenethyl Ester ◽  
Mitogen Activated Protein Kinase ◽  
Antidepressant Effect ◽  
Chronic Unpredictable Stress ◽  
Western Blots ◽  
Corticosterone Secretion ◽  
Mitogen Activated Protein

Caffeic acid phenethyl ester (CAPE) is an active component of propolis that has a variety of potential pharmacological effects. Although we previously demonstrated that propolis has antidepressant-like activity, the effect of CAPE on this activity remains unknown. The present study assessed whether treatment with CAPE (5, 10, and 20 µmol/kg for 21 days) has an antidepressant-like effect in mice subjected to chronic unpredictable stress via tail suspension (TST) and forced swim (FST) tests. CAPE administration induced behaviors consistent with an antidepressant effect, evidenced by decreased immobility in the TST and FST independent of any effect on serum corticosterone secretion. Western blots, conducted subsequent to behavioral assessment, revealed that CAPE significantly decreased glucocorticoid receptor phosphorylation at S234 (pGR(S234)), resulting in an increased pGR(S220/S234) ratio. We also observed negative correlations between pGR(S220)/(S234) and p38 mitogen-activated protein kinase (p38MAPK) phosphorylation, which was decreased by CAPE treatment. These findings suggest that CAPE treatment exerts an antidepressant-like effect via downregulation of p38MAPK phosphorylation, thereby contributing to enhanced GR function.

scholarly journals MEKK1 activates both IκB kinase α and IκB kinase β

1998 ◽  
Vol 95 (16) ◽  
pp. 9319-9324 ◽  
Author(s):  
Frank S. Lee ◽  
Robert T. Peters ◽  
Luan C. Dang ◽  
Tom Maniatis
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Mitogen Activated Protein Kinase ◽  
Site Specific ◽  
Iκb Kinase ◽  
Mitogen Activated Protein ◽  
Bona Fide ◽  
Factor Α

A critical step in the signal-induced activation of the transcription factor NF-κB is the site-specific phosphorylation of its inhibitor, IκB, that targets the latter for degradation by the ubiquitin–proteasome pathway. We have previously shown that mitogen-activated protein kinase/ERK kinase kinase 1 (MEKK1) can induce both this site-specific phosphorylation of IκBα at Ser-32 and Ser-36 in vivo and the activity of a high molecular weight IκB kinase complex in vitro. Subsequently, others have identified two proteins, IκB kinase α (IKK-α) and IκB kinase β (IKK-β), that are present in a tumor necrosis factor α-inducible, high molecular weight IκB kinase complex. These kinases are believed to directly phosphorylate IκB based on the examination of the kinase activities of IKK immunoprecipitates, but more rigorous proof of this has yet to be demonstrated. We show herein that recombinant IKK-α and IKK-β can, in fact, directly phosphorylate IκBα at Ser-32 and Ser-36, as well as homologous residues in IκBβ in vitro, and thus are bona fide IκB kinases. We also show that MEKK1 can induce the activation of both IKK-α and IKK-β in vivo. Finally, we show that IKK-α is present in the MEKK1-inducible, high molecular weight IκB kinase complex and treatment of this complex with MEKK1 induces phosphorylation of IKK-α in vitro. We conclude that IKK-α and IKK-β can mediate the NF-κB-inducing activity of MEKK1.

scholarly journals ERK5 Is a Novel Type of Mitogen-Activated Protein Kinase Containing a Transcriptional Activation Domain

2000 ◽  
Vol 20 (22) ◽  
pp. 8382-8389 ◽  
Author(s):  
Herbert G. Kasler ◽  
Joseph Victoria ◽  
Omar Duramad ◽  
Astar Winoto
Keyword(s):  
T Cells ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Antigen Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Calcium Flux ◽  
Activation Domain ◽  
Transcriptional Activation Domain ◽  
Mitogen Activated Protein

ABSTRACT Previous studies have shown that upregulation of the orphan steroid receptor Nur77 is required for the apoptosis of immature T cells in response to antigen receptor signals. Transcriptional upregulation of Nur77 in response to antigen receptor signaling involves two binding sites for the MEF2 family of transcription factors located in the Nur77 promoter. Calcium signals greatly increase the activity of MEF2D in T cells via a posttranslational mechanism. The mitogen-activated protein (MAP) kinase ERK5 was isolated in a yeast two-hybrid screen using the MADS-MEF2 domain of MEF2D as bait. ERK5 resembles the other MAP kinase family members in its N-terminal half, but it also contains a 400-amino-acid C-terminal domain of previously uncharacterized function. We report here that the C-terminal region of ERK5 contains a MEF2-interacting domain and, surprisingly, also a potent transcriptional activation domain. These domains are both required for coactivation of MEF2D by ERK5. The MEF2-ERK5 interaction was found to be activation dependent in vivo and inhibitable in vitro by the calcium-sensitive MEF2 repressor Cabin 1. The transcriptional activation domain of ERK5 is required for maximal MEF2 activity in response to calcium flux in T cells, and it can activate the endogenous Nur77 gene when constitutively recruited to the Nur77 promoter via MEF2 sites. These studies provide insights into a mechanism whereby MEF2 activity can respond to calcium signaling and suggest a novel, unexpected mechanism of MAP kinase function.

scholarly journals Proinsulin C-peptide activates cAMP response element-binding proteins through the p38 mitogen-activated protein kinase pathway in mouse lung capillary endothelial cells

2002 ◽  
Vol 366 (3) ◽  
pp. 737-744 ◽  
Author(s):  
Takanori KITAMURA ◽  
Kazuhiro KIMURA ◽  
Bae Dong JUNG ◽  
Kennedy MAKONDO ◽  
Naoki SAKANE ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Mouse Lung ◽  
Camp Response Element ◽  
Site Specific ◽  
C Peptide ◽  
Mitogen Activated Protein ◽  
Capillary Endothelial Cells ◽  
Kinase Pathway ◽  
Stimulation Of

Proinsulin C-peptide has been reported to have some biological activities and to be possibly involved in the development of diabetic microangiopathy. In the present study, we examined the effects of C-peptide on the mitogen-activated protein kinase pathway in LEII mouse lung capillary endothelial cells. Stimulation of the cells with C-peptide increased both p38 mitogen-activated protein kinase (p38MAPK) and extracellular signal-regulated kinase (ERK1/2) activities and activity-related site-specific phosphorylation of the respective kinases in a concentration-dependent manner, but failed to activate c-Jun N-terminal kinase. Stimulation of the cells with C-peptide also induced site-specific phosphorylation of cAMP response element (CRE)-binding protein (CREB)/activating transcription factor 1 (ATF1), and thereby binding of these transcription factors to CRE. Among three CREB kinases tested, phosphorylation of mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2) was induced after stimulation with C-peptide. The phosphorylation of CREB, ATF1 and MAPKAP-K2 were inhibited by SB203580, a p38MAPK inhibitor, but not by PD98059, an ERK kinase inhibitor. These results indicate that C-peptide activates p38MAPK followed by MAPKAP-K2 to enhance DNA—CREB/ATF1 interactions.

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