scholarly journals PfPK6, a novel cyclin-dependent kinase/mitogen-activated protein kinase-related protein kinase from Plasmodium falciparum

2000 ◽  
Vol 347 (1) ◽  
pp. 255-263 ◽  
Author(s):  
Valerie BRACCHI-RICARD ◽  
Sailen BARIK ◽  
Cherie DELVECCHIO ◽  
Christian DOERIG ◽  
Ratna CHAKRABARTI ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Kinase ◽  
Catalytic Domain ◽  
Sequence Similarity ◽  
Small Subunit ◽  
Mitogen Activated Protein Kinase ◽  
Cdna Clones ◽  
Cyclin Dependent Kinase ◽  
Mitogen Activated Protein

We have isolated a novel protein kinase cDNA, PfPK6, by differential display RT-PCR (DDRT-PCR) of mRNA obtained from different asexual erythrocytic stages of Plasmodium falciparum, which shows sequence similarity to both cyclin-dependent kinase (CDK) and mitogen-activated protein kinase (MAPK) family members. The 915 bp open reading frame (ORF) is interrupted by seven introns and encodes a 305-residue polypeptide with a predicted molecular mass of 35848 Da. Several cDNA clones with some of the intron sequences were isolated, indicating alternate or defective splicing of PfPK6 transcripts because the gene seems to be a single copy located on chromosome 13. The similarity of the catalytic domain of PfPK6 to those of CDK2 and MAPK is 57.3% and 49.6%, respectively. The signature PSTAIRE (single-letter amino acid codes) CDK motif is changed to SKCILRE in PfPK6. The TXY residues that are phosphorylated in MAPKs for their activation are T173PT in PfPK6. Three size classes of PfPK6 transcripts of 6.5, 2.0 and 1.1 kb are up-regulated during the transition of P. falciparum from ring to trophozoite. Western blot analysis suggested the expression of a 35 kDa polypeptide in trophozoites and schizonts. Immunofluorescence studies indicated both nuclear and cytoplasmic localization of PfPK6 in trophozoite, schizont and segmenter stages. In vitro, recombinant PfPK6 phosphorylated itself and also exogenous substrates, histone and the small subunit of the malarial ribonucleotide reductase (R2). The kinase activity of PfPK6 is sensitive to CDK inhibitors such as olomoucine and roscovitine. PfPK6 showed a preference for Mn2+ over Mg2+ ions as a cofactor. The Lys38 → Arg mutant is severely defective in its interaction with ATP and bivalent cations and somewhat defective in catalytic rate for R2 phosphorylation.

scholarly journals PfPK6, a novel cyclin-dependent kinase/mitogen-activated protein kinase-related protein kinase from Plasmodium falciparum

2000 ◽  
Vol 347 (1) ◽  
pp. 255 ◽  
Author(s):  
Valerie BRACCHI-RICARD ◽  
Sailen BARIK ◽  
Cherie DELVECCHIO ◽  
Christian DOERIG ◽  
Ratna CHAKRABARTI ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Cyclin Dependent Kinase ◽  
Related Protein ◽  
Mitogen Activated Protein

scholarly journals Activation of a Nuclear Cdc2-Related Kinase within a Mitogen-Activated Protein Kinase-Like TDY Motif by Autophosphorylation and Cyclin-Dependent Protein Kinase-Activating Kinase

2005 ◽  
Vol 25 (14) ◽  
pp. 6047-6064 ◽  
Author(s):  
Zheng Fu ◽  
Melanie J. Schroeder ◽  
Jeffrey Shabanowitz ◽  
Philipp Kaldis ◽  
Kasumi Togawa ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nuclear Localization ◽  
Kinase Activity ◽  
Catalytic Domain ◽  
Mitogen Activated Protein Kinase ◽  
Intestinal Cell ◽  
Dependent Protein Kinase ◽  
Mitogen Activated Protein ◽  
Dependent Protein

ABSTRACT Male germ cell-associated kinase (MAK) and intestinal cell kinase (ICK) are nuclear Cdc2-related kinases with nearly identical N-terminal catalytic domains and more divergent C-terminal noncatalytic domains. The catalytic domain is also related to mitogen-activated protein kinases (MAPKs) and contains a corresponding TDY motif. Nuclear localization of ICK requires subdomain XI and interactions of the conserved Arg-272, but not kinase activity or, surprisingly, any of the noncatalytic domain. Further, nuclear localization of ICK is required for its activation. ICK is activated by dual phosphorylation of the TDY motif. Phosphorylation of Tyr-159 in the TDY motif requires ICK autokinase activity but confers only basal kinase activity. Full activation requires additional phosphorylation of Thr-157 in the TDY motif. Coexpression of ICK with constitutively active MEK1 or MEK5 fails to increase ICK phosphorylation or activity, suggesting that MEKs are not involved. ICK and MAK are related to Ime2p in budding yeast, and cyclin-dependent protein kinase-activating kinase Cak1p has been placed genetically upstream of Ime2p. Recombinant Cak1p phosphorylates Thr-157 in the TDY motif of recombinant ICK and activates its activity in vitro. Coexpression of ICK with wild-type CAK1 but not kinase-inactive CAK1 in cells also increases ICK phosphorylation and activity. Our studies establish ICK as the prototype for a new group of MAPK-like kinases requiring dual phosphorylation at TDY motifs.

scholarly journals Human mitogen-activated protein kinase kinase kinase mediates the stress-induced activation of mitogen-activated protein kinase cascades

1998 ◽  
Vol 336 (3) ◽  
pp. 599-609 ◽  
Author(s):  
Po-Ying CHAN-HUI ◽  
Robert WEAVER
Keyword(s):  
Protein Kinase ◽  
Sequence Similarity ◽  
K562 Cells ◽  
Mitogen Activated Protein Kinase ◽  
Hek293 Cells ◽  
Mapk Cascades ◽  
Mitogen Activated Protein ◽  
Factor Α

The mitogen-activated protein kinase (MAPK) cascades represent one of the important signalling mechanisms in response to environmental stimuli. We report the identification of a human MAPK kinase kinase, MAPKKK4, via sequence similarity with other MAPKKKs. When truncated MAPKKK4 (ΔMAPKKK4) was overexpressed in HEK293 cells, it was constitutively active and induced the activation of endogenous p38α, c-Jun N-terminal kinase (JNK)1/2 and extracellular signal-regulated kinase (ERK)2 in vivo. Kinase-inactive ΔMAPKKK4 partly inhibited the activation of p38α, JNK1/2 and ERK2 induced by stress, tumour necrosis factor α or epidermal growth factor, suggesting that MAPKKK4 might be physiologically involved in all three MAPK cascades. Co-expressed MAP kinase kinase (MKK)-1, MKK-4, MKK-3 and MKK-6 were activated in vivo by ΔMAPKKK4. All of the above MKKs purified from Escherichia coli were phosphorylated and activated by ΔMAPKKK4 immunoprecipitates in vitro. When expressed by lower plasmid doses, ΔMAPKKK4 preferentially activated MKK-3 and p38α in vivo. Overexpression of ΔMAPKKK4 did not activate the NF-κB pathway. Immunoprecipitation of endogenous MAPKKK4 by specific antibodies showed that MAPKKK4 was activated after the treatment of K562 cells with various stress conditions. As a broadly distributed kinase, MAPKKK4 might serve as a stress responder. MAPKKK4 is 91% identical with the recently described murine MEKK-4β and might be its human homologue. It is also identical with the recently cloned human MAP three kinase 1 except for the lack of an internal sequence homologous to the murine MEKK-4α isoform. Differences in the reported functional activities of the three kinases are discussed.

scholarly journals An analysis of the phosphorylation and activation of extracellular-signal-regulated protein kinase 5 (ERK5) by mitogen-activated protein kinase kinase 5 (MKK5) in vitro

2003 ◽  
Vol 372 (2) ◽  
pp. 567-575 ◽  
Author(s):  
Nimesh MODY ◽  
David G. CAMPBELL ◽  
Nick MORRICE ◽  
Mark PEGGIE ◽  
Philip COHEN
Keyword(s):  
Protein Kinase ◽  
Catalytic Domain ◽  
Similar Rate ◽  
Mitogen Activated Protein Kinase ◽  
Glutathione S Transferase ◽  
293 Cells ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Protein Kinase Kinase

MKK5 expressed as a glutathione S-transferase fusion protein in human embryonic kidney 293 cells activated full-length extracellular-signal-regulated protein kinase (ERK)5 (ERK5wt) as well as the isolated catalytic domain (ERK5cat) in vitro. Activation was accompanied by the phosphorylation of Thr219 and Tyr221, the former residue being phosphorylated preferentially. ERK5cat phosphorylated at Thr219, but not Tyr221, possessed 10% of the activity of the doubly phosphorylated protein towards myelin basic protein, whereas ERK5cat phosphorylated at Tyr221 alone was much less active. Activated ERK5 phosphorylated itself at a number of residues, including Thr28, Ser421, Ser433, Ser496, Ser731 and Thr733. ERK5 phosphorylated at Thr219, but not Tyr221, phosphorylated itself at a similar rate to ERK5 phosphorylated at both Thr219 and Tyr221. Activated ERK5 also phosphorylated mitogen-activated protein kinase kinase 5 (MKK5) extensively at Ser129, Ser137, Ser142 and Ser149, which are located within the region in MKK5 that is thought to interact with ERK5.

scholarly journals Enhanced Toll-Like Receptor Responsiveness Associated with Mitogen-Activated Protein Kinase Activation in Plasmodium falciparum-Infected Children

2008 ◽  
Vol 76 (11) ◽  
pp. 5149-5157 ◽  
Author(s):  
Franca C. Hartgers ◽  
Benedicta B. Obeng ◽  
Astrid Voskamp ◽  
Irene A. Larbi ◽  
Abena S. Amoah ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Kinase ◽  
Mononuclear Cells ◽  
Innate Immune ◽  
Mitogen Activated Protein Kinase ◽  
Peripheral Blood Mononuclear ◽  
Kinase Activation ◽  
Protein Kinase Activation ◽  
Mitogen Activated Protein

ABSTRACT Acute Plasmodium falciparum infection is associated with strongly upregulated cytokine responses that are at least partly the result of activation of Toll-like receptors (TLRs). Whether and how TLR expression/responsiveness changes upon malarial infection is, however, currently not well understood. To assess this, we examined expression of TLRs and used the TLR ligand lipopolysaccharide (LPS) and Pam3Cys to stimulate peripheral blood mononuclear cells (PBMCs) from Ghanaian schoolchildren who live in a rural area where P. falciparum is endemic. Expression of TLR2 was higher, and responses to its ligand, Pam3Cys, were enhanced in P. falciparum-infected children compared to their uninfected counterparts. In cells from the same children, stimulation by Pam3Cys resulted in higher p38 mitogen-activated protein kinase activation and higher cytokine production. In vitro experiments confirmed that preincubation of PBMCs with P. falciparum-infected red blood cells enhanced responsiveness to TLR ligands. Taken together, the data indicate that P. falciparum-infected children in areas where malaria is endemic have an altered innate immune system, which might be important for the balance between immunity and pathology when new infections are encountered or when novel vaccines are introduced.

scholarly journals Ser-3 is important for regulating Mos interaction with and stimulation of mitogen-activated protein kinase kinase.

1995 ◽  
Vol 15 (9) ◽  
pp. 4727-4734 ◽  
Author(s):  
M Chen ◽  
J A Cooper
Keyword(s):  
Protein Kinase ◽  
Catalytic Domain ◽  
Mitogen Activated Protein Kinase ◽  
Early Embryos ◽  
Mitogen Activated Protein ◽  
Hybrid Test ◽  
Two Hybrid ◽  
Autophosphorylation Site ◽  
Protein Kinase Kinase

Mos is a germ cell-specific serine/threonine protein kinase that activates mitogen-activated protein kinase (MAPK) through MAPK kinase (MKK). In Xenopus oocytes, Mos synthesis is required for progesterone-induced activation of MAPK and maturation promoting factor. Injection of Mos or active MAPK causes mitotic arrest in early embryos, suggesting that Mos also acts via MKK and MAPK to induce the arrest of unfertilized eggs in metaphase of meiosis II. We have investigated whether Mos activity is regulated by phosphorylation. Previous studies have identified Ser-3 as the principal autophosphorylation site. We show that Mos interacts with the catalytic domain of MKK in a Saccharomyces cerevisiae two-hybrid test. Acidic substitutions of the sites phosphorylated by Mos in MKK reduce the interaction, implying that the complex may dissociate after phosphorylation of MKK by Mos. Furthermore, the Mos-MKK interaction requires Mos kinase activity, suggesting that Mos autophosphorylation may be involved in the interaction. Substitution of Ser-3 of Mos with Ala reduces the interaction with MKK and also reduces both the activation of MKK by Mos in vitro and cleavage arrest induced by Mos fusion protein in Xenopus embryos. By contrast, substitution of Ser-3 by Glu, an acidic amino acid that mimics phosphoserine, fosters the Mos interaction with MKK and permits activation of MKK in vitro and Mos-induced cleavage arrest. Moreover, the Glu-3 substitution increases the interaction of a kinase-inactive Mos mutant with MKK. Taken together, these results suggest that an important step in Mos activation involves the phosphorylation at Ser-3, which promotes Mos interaction with and activation of MKK.

scholarly journals Cross-talk between IRAK-4 and the NADPH oxidase1

2007 ◽  
Vol 403 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Sandrine Pacquelet ◽  
Jennifer L. Johnson ◽  
Beverly A. Ellis ◽  
Agnieszka A. Brzezinska ◽  
William S. Lane ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Free System ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Tlr4 Activation

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.

scholarly journals Dual-mode regulation of the APC/C by CDK1 and MAPK controls meiosis I progression and fidelity

2014 ◽  
Vol 204 (6) ◽  
pp. 891-900 ◽  
Author(s):  
Ibtissem Nabti ◽  
Petros Marangos ◽  
Jenny Bormann ◽  
Nobuaki R. Kudo ◽  
John Carroll
Keyword(s):  
Protein Kinase ◽  
Spindle Assembly Checkpoint ◽  
Mitogen Activated Protein Kinase ◽  
Cyclin Dependent Kinase ◽  
Anaphase Promoting Complex ◽  
Female Meiosis ◽  
Dual Mode ◽  
Mitogen Activated Protein ◽  
Meiosis I

Female meiosis is driven by the activities of two major kinases, cyclin-dependent kinase 1 (Cdk1) and mitogen-activated protein kinase (MAPK). To date, the role of MAPK in control of meiosis is thought to be restricted to maintaining metaphase II arrest through stabilizing Cdk1 activity. In this paper, we find that MAPK and Cdk1 play compensatory roles to suppress the anaphase-promoting complex/cyclosome (APC/C) activity early in prometaphase, thereby allowing accumulation of APC/C substrates essential for meiosis I. Furthermore, inhibition of MAPK around the onset of APC/C activity at the transition from meiosis I to meiosis II led to accelerated completion of meiosis I and an increase in aneuploidy at metaphase II. These effects appear to be mediated via a Cdk1/MAPK-dependent stabilization of the spindle assembly checkpoint, which when inhibited leads to increased APC/C activity. These findings demonstrate new roles for MAPK in the regulation of meiosis in mammalian oocytes.

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