scholarly journals The phosphorylation of CapZ-interacting protein (CapZIP) by stress-activated protein kinases triggers its dissociation from CapZ

2005 ◽  
Vol 389 (1) ◽  
pp. 127-135 ◽  
Author(s):  
Claire E. EYERS ◽  
Helen McNEILL ◽  
Axel KNEBEL ◽  
Nick MORRICE ◽  
Simon J. C. ARTHUR ◽  
...  

A protein expressed in immune cells and muscle was detected in muscle extracts as a substrate for several SAPKs (stress-activated protein kinases). It interacted specifically with the F-actin capping protein CapZ in splenocytes, and was therefore termed ‘CapZIP’ (CapZ-interacting protein). Human CapZIP was phosphorylated at Ser-179 and Ser-244 by MAPKAP-K2 (mitogen-activated protein kinase-activated protein kinase 2) or MAPKAP-K3 in vitro. Anisomycin induced the phosphorylation of CapZIP at Ser-179 in Jurkat cells, which was prevented by SB 203580, consistent with phosphorylation by MAPKAP-K2 and/or MAPKAP-K3. However, osmotic shock-induced phosphorylation of Ser-179 was unaffected by SB 203580. These and other results suggest that CapZIP is phosphorylated at Ser-179 in cells by MAPKAP-K2/MAPKAP-K3, and at least one other protein kinase. Stress-activated MAP kinase family members phosphorylated human CapZIP at many sites, including Ser-68, Ser-83, Ser-108 and Ser-216. Ser-108 became phosphorylated when Jurkat cells were exposed to osmotic shock, which was unaffected by SB 203580 and/or PD 184352, or in splenocytes from mice that do not express either SAPK3/p38γ or SAPK4/p38δ. Our results suggest that CapZIP may be phosphorylated by JNK (c-Jun N-terminal kinase), which phosphorylates CapZIP to >5 mol/mol within minutes in vitro. Osmotic shock or anisomycin triggered the dissociation of CapZIP from CapZ in Jurkat cells, suggesting that phosphorylation of CapZIP may regulate the ability of CapZ to remodel actin filament assembly in vivo.

2004 ◽  
Vol 379 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Yvonne KUMA ◽  
David G. CAMPBELL ◽  
Ana CUENDA

The endogenous glycogen synthase in extracts from mouse skeletal muscle, liver and brain bound specifically to SAPK2b (stress-activated protein kinase 2b)/p38β, but not to other members of the group of SAPK/p38 kinases. Glycogen synthase was phosphorylated in vitro more efficiently by SAPK2b/p38β than by SAPK2a/p38α, SAPK3/p38γ or SAPK4/p38δ. SAPK2b/p38β phosphorylated glycogen synthase in vitro at residues Ser644, Ser652, Thr718 and Ser724, two of which (Ser644 and Ser652) are also phosphorylated by glycogen synthase kinase 3. Thr718 and Ser724 are novel sites not known to be phosphorylated by other protein kinases. Glycogen synthase becomes phosphorylated at Ser644 in response to osmotic shock; this phosphorylation is prevented by pretreatment of the cells with SB 203580, which inhibits SAPK2a/p38α and SAPK2b/p38β activity. In vitro, phosphorylation of glycogen synthase by SAPK2b/p38β alone had no significant effect on its activity, indicating that phosphorylation at residue Ser644 itself is insufficient to decrease glycogen synthase activity. However, after phosphorylation by SAPK2b/p38β, subsequent phosphorylation at Ser640 by glycogen synthase kinase 3 decreased the activity of glycogen synthase. This decrease was not observed when SAPK2b/p38β activity was blocked with SB 203580. These results suggest that SAPK2b/p38β may be a priming kinase that allows glycogen synthase kinase 3 to phosphorylate Ser640 and thereby inhibit glycogen synthase activity.


2012 ◽  
Vol 123 (3) ◽  
pp. 147-159 ◽  
Author(s):  
Ting-Hsing Chao ◽  
Shih-Ya Tseng ◽  
Yi-Heng Li ◽  
Ping-Yen Liu ◽  
Chung-Lung Cho ◽  
...  

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yanfei Du ◽  
Jun Ma ◽  
Yu Fan ◽  
Xinyu Wang ◽  
Shuzhan Zheng ◽  
...  

Fibrosis is the final common pathology of most chronic diseases as seen in the heart, liver, lung, kidney, and skin and contributes to nearly half of death in the developed countries. Fibrosis, or scarring, is mainly characterized by the transdifferentiation of fibroblasts into myofibroblasts and the excessive accumulation of extracellular matrix (ECM) secreted by myofibroblasts. Despite immense efforts made in the field of organ fibrosis over the past decades and considerable understanding of the occurrence and development of fibrosis gained, there is still lack of an effective treatment for fibrotic diseases. Therefore, identifying a new therapeutic strategy against organ fibrosis is an unmet clinical need. Naringenin, a flavonoid that occurs naturally in citrus fruits, has been found to confer a wide range of pharmacological effects including antioxidant, anti-inflammatory, and anticancer benefits and thus potentially exerting preventive and curative effects on numerous diseases. In addition, emerging evidence has revealed that naringenin can prevent the pathogenesis of fibrosis in vivo and in vitro via the regulation of various pathways that involved signaling molecules such as transforming growth factor-β1/small mother against decapentaplegic protein 3 (TGF-β1/Smad3), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), sirtuin1 (SIRT1), nuclear factor-kappa B (NF-κB), or reactive oxygen species (ROS). Targeting these profibrotic pathways by naringenin could potentially become a novel therapeutic approach for the management of fibrotic disorders. In this review, we present a comprehensive summary of the antifibrotic roles of naringenin in vivo and in vitro and their underlying mechanisms of action. As a food derived compound, naringenin may serve as a promising drug candidate for the treatment of fibrotic disorders.


1997 ◽  
Vol 110 (12) ◽  
pp. 1373-1386 ◽  
Author(s):  
G.R. Walker ◽  
C.B. Shuster ◽  
D.R. Burgess

Research over the past few years has demonstrated the central role of protein phosphorylation in regulating mitosis and the cell cycle. However, little is known about how the mechanisms regulating the entry into mitosis contribute to the positional and temporal regulation of the actomyosin-based contractile ring formed during cytokinesis. Recent studies implicate p34cdc2 as a negative regulator of myosin II activity, suggesting a link between the mitotic cycle and cytokinesis. In an effort to study the relationship between protein phosphorylation and cytokinesis, we examined the in vivo and in vitro phosphorylation of actin-associated cortical cytoskeletal (CSK) proteins in an isolated model of the sea urchin egg cortex. Examination of cortices derived from eggs or zygotes labeled with 32P-orthophosphate reveals a number of cortex-associated phosphorylated proteins, including polypeptides of 20, 43 and 66 kDa. These three major phosphoproteins are also detected when isolated cortices are incubated with [32P]ATP in vitro, suggesting that the kinases that phosphorylate these substrates are also specifically associated with the cortex. The kinase activities in vivo and in vitro are stimulated by fertilization and display cell cycle-dependent activities. Gel autophosphorylation assays, kinase assays and immunoblot analysis reveal the presence of p34cdc2 as well as members of the mitogen-activated protein kinase family, whose activities in the CSK peak at cell division. Nocodazole, which inhibits microtubule formation and thus blocks cytokinesis, significantly delays the time of peak cortical protein phosphorylation as well as the peak in whole-cell histone H1 kinase activity. These results suggest that a key element regulating cortical contraction during cytokinesis is the timing of protein kinase activities associated with the cortical cytoskeleton that is in turn regulated by the mitotic apparatus.


2020 ◽  
Vol 11 ◽  
Author(s):  
Jinpeng Lv ◽  
Songzhou Jiang ◽  
Ying Yang ◽  
Ximei Zhang ◽  
Rongyin Gao ◽  
...  

FGIN-1-27 is a synthetic mitochondrial diazepam binding inhibitor receptor (MDR) agonist that has demonstrated pro-apoptotic, anti-anxiety, and steroidogenic activity in various studies. Here we report, for the first time, the anti-melanogenic efficacy of FGIN-1-27 in vitro and in vivo. FGIN-1-27 significantly inhibited basal and α-melanocyte-stimulating hormone (α-MSH)-, 1-Oleoyl-2-acetyl-sn-glycerol (OAG)- and Endothelin-1 (ET-1)-induced melanogenesis without cellular toxicity. Mushroom tyrosinase activity assay showed that FGIN-1-27 did not directly inhibit tyrosinase activity, which suggested that FGIN-1-27 was not a direct inhibitor of tyrosinase. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, FGIN-1-27 downregulated the expression levels of key proteins that function in melanogenesis. FGIN-1-27 played these functions mainly by suppressing the PKA/CREB, PKC-β, and MAPK pathways. Once inactivated, it decreased the expression of MITF, tyrosinase, TRP-1, TRP-2, and inhibited the tyrosinase activity, finally inhibiting melanogenesis. During in vivo experiments, FGIN-1-27 inhibited the body pigmentation of zebrafish and reduced UVB-induced hyperpigmentation in guinea pig skin, but not a reduction of numbers of melanocytes. Our findings indicated that FGIN-1-27 exhibited no cytotoxicity and inhibited melanogenesis in both in vitro and in vivo models. It may prove quite useful as a safer skin-whitening agent.


2020 ◽  
Vol 40 (7) ◽  
Author(s):  
Johanna J. Sjölander ◽  
Agata Tarczykowska ◽  
Cecilia Picazo ◽  
Itziar Cossio ◽  
Itedale Namro Redwan ◽  
...  

ABSTRACT Oxidation of a highly conserved cysteine (Cys) residue located in the kinase activation loop of mitogen-activated protein kinase kinases (MAPKK) inactivates mammalian MKK6. This residue is conserved in the fission yeast Schizosaccharomyces pombe MAPKK Wis1, which belongs to the H2O2-responsive MAPK Sty1 pathway. Here, we show that H2O2 reversibly inactivates Wis1 through this residue (C458) in vitro. We found that C458 is oxidized in vivo and that serine replacement of this residue significantly enhances Wis1 activation upon addition of H2O2. The allosteric MAPKK inhibitor INR119, which binds in a pocket next to the activation loop and C458, prevented the inhibition of Wis1 by H2O2 in vitro and significantly increased Wis1 activation by low levels of H2O2 in vivo. We propose that oxidation of C458 inhibits Wis1 and that INR119 cancels out this inhibitory effect by binding close to this residue. Kinase inhibition through the oxidation of a conserved Cys residue in MKK6 (C196) is thus conserved in the S. pombe MAPKK Wis1.


2009 ◽  
Vol 77 (4) ◽  
pp. 1569-1578 ◽  
Author(s):  
Jong-Hwan Park ◽  
Yun-Gi Kim ◽  
Gabriel Núñez

ABSTRACT RICK (receptor-interacting protein-like interacting caspase-like apoptosis regulatory protein kinase), a serine-threonine kinase, functions downstream of the pattern recognition receptors Nod1 and Nod2 to mediate NF-κB and mitogen-activated protein kinase (MAPK) activation in response to specific microbial stimuli. However, the function of RICK in the recognition and host defense of gram-negative bacteria remains poorly understood. We report here that infection of wild-type and RICK-deficient macrophages with Pseudomonas aeruginosa and Escherichia coli elicited comparable activation of NF-κB and MAPKs as well as secretion of proinflammatory cytokines. However, production of interleukin 6 (IL-6) and IL-1β induced by these gram-negative bacteria was impaired in RICK-deficient macrophages when the cells had previously been stimulated with lipopolysaccharide (LPS) or E. coli. The diminished proinflammatory response of RICK-deficient macrophages to bacteria was associated with reduced activation of NF-κB and MAPKs. Importantly, mutant mice deficient in RICK were less susceptible than wild-type mice to P. aeruginosa infection when the animals had previously been stimulated with LPS. The reduced lethality of RICK-deficient mice infected with P. aeruginosa was independent of pathogen clearance but was associated with diminished production of proinflammatory molecules in vivo. These results demonstrate that RICK contributes to the induction of proinflammatory responses and susceptibility to gram-negative bacteria after exposure to LPS, a condition that is associated with reduced Toll-like receptor signaling.


2019 ◽  
Vol 20 (8) ◽  
pp. 1931
Author(s):  
Eva Louise Steinmetz ◽  
Denise Nicole Dewald ◽  
Nadine Luxem ◽  
Uwe Walldorf

The Drosophila homeodomain-interacting protein kinase (Hipk) is the fly representative of the well-conserved group of HIPKs in vertebrates. It was initially found through its characteristic interactions with homeodomain proteins. Hipk is involved in a variety of important developmental processes, such as the development of the eye or the nervous system. In the present study, we set Hipk and the Drosophila homeodomain proteins Homeobrain (Hbn), Empty spiracles (Ems), and Muscle segment homeobox (Msh) in an enzyme-substrate relationship. These homeoproteins are transcription factors that function during Drosophila neurogenesis and are, at least in part, conserved in vertebrates. We reveal a physical interaction between Hipk and the three homeodomain proteins in vivo using bimolecular fluorescence complementation (BiFC). In the course of in vitro phosphorylation analysis and subsequent mutational analysis we mapped several Hipk phosphorylation sites of Hbn, Ems, and Msh. The phosphorylation of Hbn, Ems, and Msh may provide further insight into the function of Hipk during development of the Drosophila nervous system.


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