Stressing the role of MAP kinases in mitogenic stimulation

2000 ◽  
pp. 161-174
Author(s):  
László Bögre ◽  
Irute Meskiene ◽  
Erwin Heberle-Bors ◽  
Heribert Hirt
2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.


2005 ◽  
Vol 7 (11-12) ◽  
pp. 1773-1782 ◽  
Author(s):  
M. Paola Zago ◽  
Gerardo G. Mackenzie ◽  
Ana M. Adamo ◽  
Carl L. Keen ◽  
Patricia I. Oteiza

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Galileo Escobedo ◽  
Gloria Soldevila ◽  
Guadalupe Ortega-Pierres ◽  
Jesús Ramsés Chávez-Ríos ◽  
Karen Nava ◽  
...  

MAP kinases (MAPK) are involved in the regulation of cellular processes such as reproduction and growth. In parasites, the role of MAPK has been scarcely studied. Here, we describe the participation of an ERK-like protein in estrogen-dependent reproduction of the helminth parasiteTaenia crassiceps. Our results show that 17β-estradiol induces a concentration-dependent increase in the bud number of in vitro cultured cysticerci. If parasites are also incubated in presence of an ERK-inhibitor, the stimulatory effect of estrogen is blocked. The expression of ERK-like mRNA and its corresponding protein was detected in the parasite. The ERK-like protein was over-expressed by all treatments. Nevertheless, a strong induction of phosphorylation of this protein was observed only in response to 17β-estradiol. Cross-contamination by host cells was discarded by flow cytometry analysis. Parasite cells expressing the ERK-like protein were exclusively located at the subtegument tissue by confocal microscopy. Finally, the ERK-like protein was separated by bidimensional electrophoresis and then sequenced, showing the conserved TEY activation motif, typical of all known ERK 1/2 proteins. Our results show that an ERK-like protein is involved in the molecular signalling during the interaction between the host andT. crassiceps, and may be considered as target for anti-helminth drugs design.


1993 ◽  
Vol 340 (1293) ◽  
pp. 325-332 ◽  

Many genes which are regulated by growth factors contain a common regulatory element, the serum response element (SRE). Activation of transcription by the SRE involves a ternary complex formed between a ubiquitous factor, serum response factor (SRF), and a second protein, p62/TCF. We used a yeast genetic screen to isolate cDNAs encoding a protein, SAP-1, with the DNA binding properties of p62/TCF. The SAP-1 sequence contains three regions of homology to the previously uncharacterized Elk-1 protein, which also acts as an SRF accessory protein. Only two of these regions are required for cooperative interactions with SRF in the ternary complex. The third contains several conserved sites for the MAP kinases, whose activity is regulated in response to growth factor stimulation. We discuss the potential role of these proteins in regulation of the c-fos SRE.


PAIN RESEARCH ◽  
2005 ◽  
Vol 20 (4) ◽  
pp. 145-152 ◽  
Author(s):  
Noguchi Koichi

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Sara M Zarate ◽  
Samantha D Francis Stuart ◽  
Robin K Young ◽  
Alice R Villalobos

2020 ◽  
Author(s):  
Purva Karia ◽  
Keiko Yoshioka ◽  
Wolfgang Moeder

ABSTRACTThe role of mitochondria in programmed cell death (PCD) during animal growth and development is well documented, but much less is known for plants. We previously showed that the Arabidopsis thaliana triphosphate tunnel metalloenzyme (TTM) proteins TTM1 and TTM2 are tail-anchored proteins that localize in the mitochondrial outer membrane and participate in PCD during senescence and immunity, respectively. Here, we show that TTM1 is specifically involved in senescence induced by abscisic acid (ABA). Moreover, phosphorylation of TTM1 by multiple mitogen-activated protein kinases (MAPKs) regulates its function and turnover. A combination of proteomics and in vitro kinase assays revealed three major phosphorylation sites of TTM1 (S10, S437, and S490), which are phosphorylated upon perception of senescence cues such as ABA and prolonged darkness. S437 is phosphorylated by the MAP kinases MPK3 and MPK4, and S437 phosphorylation is essential for TTM1 function in senescence. These MPKs, together with three additional MAP kinases (MPK1, MPK7, and MPK6), phosphorylate S10 and S490, marking TTM1 for protein turnover, which likely prevents uncontrolled cell death. Taken together, our results show that multiple MPKs regulate the function and turnover of the mitochondrial protein TTM1 during senescence-related PCD, revealing a novel link between mitochondria and PCD.SummaryEmail addresses: [email protected]


2010 ◽  
Vol 2 (3) ◽  
pp. 125-138 ◽  
Author(s):  
Malgorzata Krzyzowska ◽  
Weronika Swiatek ◽  
Beata Fijalkowska ◽  
Marek Niemialtowski ◽  
Ada Schollenberger

Summary The MAP kinases (MAPKs), including ERK, JNK and p38 families comprise part of the intracellular signalling network, which is essential for signal transduction from receptors and stimuli to the biological reaction. Activity of MAPKs plays a crucial role in normal functioning of the immune system. By taking part in cytokine production upon signalling from activated TLR receptors, MAPKs are involved in initiation of innate immunity and in responses to binding of cytokines by appropriate receptors. MAPKs activity is also important for T and B lymphocyte differentiation, by the ITAM signalling pathway. Moreover, their involvement in apoptosis supports lymphocyte T cytotoxicity and enables the removal of damaged, infected or transformed cells. Correct functioning of the MAPK signalling is crucial for effective immune response, and therefore MAPKs’ inhibitors constitute a promising therapeutic goal


Blood ◽  
2001 ◽  
Vol 97 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Ponlapat Rojnuckarin ◽  
Kenneth Kaushansky

Abstract With the recent cloning and characterization of thrombopoietin, appreciation of the molecular events surrounding megakaryocyte (MK) development is growing. However, the final stages of platelet formation are less well understood. Platelet production occurs after the formation of MK proplatelet processes. In a study to explore the molecular mechanisms underlying this process, mature MKs isolated from suspension murine bone marrow cell cultures were induced to form proplatelets by exposure to plasma, and the role of various cell-signaling pathways was assessed. The results showed that (1) bis-indolylmaleimide I, which blocks protein kinase C (PKC) activation; (2) down-modulation of conventional or novel classes of PKC by phorbol myristate acetate; and (3) ribozymes specific for PKCα each inhibited proplatelet formation. Inhibition of several MAP kinases, PI3 kinase, or protein kinase A failed to affect MK proplatelet formation. To gain further insights into the function of PKCα in proplatelet formation, its subcellular localization was investigated. In cultures containing active proplatelet formation, cytoplasmic polymerized actin was highly aggregated, its subcellular distribution was reorganized, and PKCα colocalized with the cellular actin aggregates. A number of MK manipulations, including blockade of integrin signaling with a disintegrin or inhibition of actin polymerization with cytochalasin D, interrupted actin reorganization, PKC relocalization, and proplatelet formation. These findings suggest an important role for PKCα in proplatelet development and suggest that it acts by altering actin dynamics in proplatelet-forming MKs. Identification of the upstream and downstream pathways involved in proplatelet formation should provide greater insights into thrombopoiesis, potentially allowing pharmacologic manipulation of the process.


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