scholarly journals Dimerization of the RamC Morphogenetic Protein of Streptomyces coelicolor

2004 ◽  
Vol 186 (5) ◽  
pp. 1330-1336 ◽  
Author(s):  
Michael E. Hudson ◽  
Justin R. Nodwell
Keyword(s):  
Protein Kinase ◽  
Streptomyces Coelicolor ◽  
Kinase Domain ◽  
Terminal Protein ◽  
Amino Terminal ◽  
Morphogenetic Protein ◽  
Aerial Hyphae ◽  
Multiple Copies ◽  
Defective Allele

ABSTRACT RamC is required for the formation of spore-forming cells called aerial hyphae by the bacterium Streptomyces coelicolor. This protein is membrane associated and has an amino-terminal protein kinase-like domain, but little is known about its mechanism of action. In this study we found that the presence of multiple copies of a defective allele of ramC inhibits morphogenesis in S. coelicolor, consistent with either titration of a target or formation of inactive RamC multimers. We identified a domain in RamC that is C terminal to the putative kinase domain and forms a dimer with a Kd of ∼0.1 μM. These data suggest that RamC acts as a dimer in vivo.

scholarly journals Normal cellular and transformation-associated abl proteins share common sites for protein kinase C phosphorylation.

1987 ◽  
Vol 7 (12) ◽  
pp. 4280-4289 ◽  
Author(s):  
A M Pendergast ◽  
J A Traugh ◽  
O N Witte
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Amino Terminal ◽  
Kinase C ◽  
Carboxy Terminal

Viral transduction and chromosomal translocations of the c-abl gene result in the synthesis of abl proteins with structurally altered amino termini. These altered forms of the abl protein, but not the c-abl proteins, are detectably phosphorylated on tyrosine in vivo. In contrast, all forms of the abl protein are phosphorylated on serine following in vivo labeling with Pi. Treatment of NIH-3T3 cells with protein kinase C activators resulted in a four- to eightfold increase in the phosphorylation of murine c-abl due to modification of two serines on the c-abl protein. Purified protein kinase C phosphorylated all abl proteins at the same two sites. Both sites are precisely conserved in murine and human abl proteins. The sites on the abl proteins were found near the carboxy terminus. In contrast, for the epidermal growth factor receptor (T. Hunter, N. Ling, and J. A. Cooper, Nature [London] 311:480-483, 1984) and pp60src (K. L. Gould, J. R. Woodgett, J. A. Cooper, J. E. Buss, D. Shalloway, and T. Hunter, Cell 42:849-857, 1985), the sites of protein kinase C phosphorylation are amino-terminal to the kinase domain. The abl carboxy-terminal region is not necessary for the tyrosine kinase activity or transformation potential of the viral abl protein and may represent a regulatory domain. Using an in vitro immune complex kinase assay, we were not able to correlate reproducible changes in c-abl activity with phosphorylation by protein kinase C. However, the high degree of conservation of the phosphorylation sites for protein kinase C between human and mouse abl proteins suggests an important functional role.

Normal cellular and transformation-associated abl proteins share common sites for protein kinase C phosphorylation

1987 ◽  
Vol 7 (12) ◽  
pp. 4280-4289
Author(s):  
A M Pendergast ◽  
J A Traugh ◽  
O N Witte
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Amino Terminal ◽  
Kinase C ◽  
Carboxy Terminal

Viral transduction and chromosomal translocations of the c-abl gene result in the synthesis of abl proteins with structurally altered amino termini. These altered forms of the abl protein, but not the c-abl proteins, are detectably phosphorylated on tyrosine in vivo. In contrast, all forms of the abl protein are phosphorylated on serine following in vivo labeling with Pi. Treatment of NIH-3T3 cells with protein kinase C activators resulted in a four- to eightfold increase in the phosphorylation of murine c-abl due to modification of two serines on the c-abl protein. Purified protein kinase C phosphorylated all abl proteins at the same two sites. Both sites are precisely conserved in murine and human abl proteins. The sites on the abl proteins were found near the carboxy terminus. In contrast, for the epidermal growth factor receptor (T. Hunter, N. Ling, and J. A. Cooper, Nature [London] 311:480-483, 1984) and pp60src (K. L. Gould, J. R. Woodgett, J. A. Cooper, J. E. Buss, D. Shalloway, and T. Hunter, Cell 42:849-857, 1985), the sites of protein kinase C phosphorylation are amino-terminal to the kinase domain. The abl carboxy-terminal region is not necessary for the tyrosine kinase activity or transformation potential of the viral abl protein and may represent a regulatory domain. Using an in vitro immune complex kinase assay, we were not able to correlate reproducible changes in c-abl activity with phosphorylation by protein kinase C. However, the high degree of conservation of the phosphorylation sites for protein kinase C between human and mouse abl proteins suggests an important functional role.

scholarly journals Membrane Association and Kinase-Like Motifs of the RamC Protein of Streptomyces coelicolor

2002 ◽  
Vol 184 (17) ◽  
pp. 4920-4924 ◽  
Author(s):  
Michael E. Hudson ◽  
Dachuan Zhang ◽  
Justin R. Nodwell
Keyword(s):  
Streptomyces Coelicolor ◽  
Membrane Association ◽  
Sequence Motifs ◽  
Filamentous Bacterium ◽  
Receptor Kinase ◽  
Null Mutant ◽  
Amino Terminal ◽  
Aerial Hyphae ◽  
Membrane Spanning

ABSTRACT The protein RamC is required for the production of the spore-forming cells called aerial hyphae by the filamentous bacterium Streptomyces coelicolor. We showed that RamC, which contains several weakly predicted membrane-spanning sequences, is located exclusively in the S. coelicolor membrane. By constructing site-directed mutants in the cloned ramC gene and complementing a ramC null mutant, we showed that protein kinase-like sequence motifs in the amino-terminal half of the protein are required for function in vivo. These data suggest that RamC is a membrane-associated receptor kinase.

scholarly journals Current translational potential and underlying molecular mechanisms of necroptosis

2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Tamás Molnár ◽  
Anett Mázló ◽  
Vera Tslaf ◽  
Attila Gábor Szöllősi ◽  
Gabriella Emri ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Kinase ◽  
Posttranslational Modifications ◽  
Molecular Mechanisms ◽  
Inflammatory Diseases ◽  
Immune Surveillance ◽  
Kinase Domain ◽  
Tumor Formation

Abstract Cell death has a fundamental impact on the evolution of degenerative disorders, autoimmune processes, inflammatory diseases, tumor formation and immune surveillance. Over the past couple of decades extensive studies have uncovered novel cell death pathways, which are independent of apoptosis. Among these is necroptosis, a tightly regulated, inflammatory form of cell death. Necroptosis contribute to the pathogenesis of many diseases and in this review, we will focus exclusively on necroptosis in humans. Necroptosis is considered a backup mechanism of apoptosis, but the in vivo appearance of necroptosis indicates that both caspase-mediated and caspase-independent mechanisms control necroptosis. Necroptosis is regulated on multiple levels, from the transcription, to the stability and posttranslational modifications of the necrosome components, to the availability of molecular interaction partners and the localization of receptor-interacting serine/threonine-protein kinase 1 (RIPK1), receptor-interacting serine/threonine-protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL). Accordingly, we classified the role of more than seventy molecules in necroptotic signaling based on consistent in vitro or in vivo evidence to understand the molecular background of necroptosis and to find opportunities where regulating the intensity and the modality of cell death could be exploited in clinical interventions. Necroptosis specific inhibitors are under development, but >20 drugs, already used in the treatment of various diseases, have the potential to regulate necroptosis. By listing necroptosis-modulated human diseases and cataloging the currently available drug-repertoire to modify necroptosis intensity, we hope to kick-start approaches with immediate translational potential. We also indicate where necroptosis regulating capacity should be considered in the current applications of these drugs.

scholarly journals An Intramolecular Association between Two Domains of the Protein Kinase Fused Is Necessary for Hedgehog Signaling

2004 ◽  
Vol 24 (23) ◽  
pp. 10397-10405 ◽  
Author(s):  
Manuel Ascano ◽  
David J. Robbins
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Hedgehog Signaling ◽  
Membrane Vesicles ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Dependent Manner ◽  
Intramolecular Association

ABSTRACT The protein kinase Fused (Fu) is an integral member of the Hedgehog (Hh) signaling pathway. Although genetic studies demonstrate that Fu is required for the regulation of the Hh pathway, the mechanistic role that it plays remains largely unknown. Given our difficulty in developing an in vitro kinase assay for Fu, we reasoned that the catalytic activity of Fu might be highly regulated. Several mechanisms are known to regulate protein kinases, including self-association in either an intra- or an intermolecular fashion. Here, we provide evidence that Hh regulates Fu through intramolecular association between its kinase domain (ΔFu) and its carboxyl-terminal domain (Fu-tail). We show that ΔFu and Fu-tail can interact in trans, with or without the kinesin-related protein Costal 2 (Cos2). However, since the majority of Fu is found associated with Cos2 in vivo, we hypothesized that Fu-tail, which binds Cos2 directly, would be able to tether ΔFu to Cos2. We demonstrate that ΔFu colocalizes with Cos2 in the presence of Fu-tail and that this colocalization occurs on a subset of membrane vesicles previously characterized to be important for Hh signal transduction. Additionally, expression of Fu-tail in fu mutant flies that normally express only the kinase domain rescues the fu wing phenotype. Therefore, reestablishing the association between these two domains of Fu in trans is sufficient to restore Hh signal transduction in vivo. In such a manner we validate our hypothesis, demonstrating that Fu self-associates and is functional in an Hh-dependent manner. Our results here enhance our understanding of one of the least characterized, yet critical, components of Hh signal transduction.

scholarly journals TAK1 Participates in c-Jun N-Terminal Kinase Signaling during Drosophila Development

2000 ◽  
Vol 20 (9) ◽  
pp. 3015-3026 ◽  
Author(s):  
Yoshihiro Takatsu ◽  
Makoto Nakamura ◽  
Mark Stapleton ◽  
Maria C. Danos ◽  
Kunihiro Matsumoto ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Transforming Growth Factor ◽  
Cultured Cells ◽  
Transforming Growth Factor Β ◽  
Kinase Domain ◽  
Dominant Negative ◽  
Jnk Signaling ◽  
Amino Terminal ◽  
Jnk Signaling Pathway

ABSTRACT Transforming growth factor β (TGF-β)-activated kinase 1 (TAK1) is a member of the MAPKKK superfamily and has been characterized as a component of the TGF-β/bone morphogenetic protein signaling pathway. TAK1 function has been extensively studied in cultured cells, but its in vivo function is not fully understood. In this study, we isolated aDrosophila homolog of TAK1 (dTAK1) which contains an extensively conserved NH2-terminal kinase domain and a partially conserved COOH-terminal domain. To learn about possible endogenous roles of TAK1 during animal development, we generated transgenic flies which express dTAK1 or the mouseTAK1 (mTAK1) gene in the fly visual system. Ectopic activation of TAK1 signaling leads to a small eye phenotype, and genetic analysis reveals that this phenotype is a result of ectopically induced apoptosis. Genetic and biochemical analyses also indicate that the c-Jun amino-terminal kinase (JNK) signaling pathway is specifically activated by TAK1 signaling. Expression of a dominant negative form of dTAK during embryonic development resulted in various embryonic cuticle defects including dorsal open phenotypes. Our results strongly suggest that in Drosophila melanogaster, TAK1 functions as a MAPKKK in the JNK signaling pathway and participates in such diverse roles as control of cell shape and regulation of apoptosis.

scholarly journals BCL-2 Is Phosphorylated and Inactivated by an ASK1/Jun N-Terminal Protein Kinase Pathway Normally Activated at G2/M

1999 ◽  
Vol 19 (12) ◽  
pp. 8469-8478 ◽  
Author(s):  
Kazuhito Yamamoto ◽  
Hidenori Ichijo ◽  
Stanley J. Korsmeyer
Keyword(s):  
Cell Cycle ◽  
Protein Kinase ◽  
Cell Cycle Progression ◽  
Peptide Mapping ◽  
Dominant Negative ◽  
Terminal Protein ◽  
Cycle Progression ◽  
M Phase ◽  
Death Signals

ABSTRACT Multiple signal transduction pathways are capable of modifying BCL-2 family members to reset susceptibility to apoptosis. We used two-dimensional peptide mapping and sequencing to identify three residues (Ser70, Ser87, and Thr69) within the unstructured loop of BCL-2 that were phosphorylated in response to microtubule-damaging agents, which also arrest cells at G2/M. Changing these sites to alanine conferred more antiapoptotic activity on BCL-2 following physiologic death signals as well as paclitaxel, indicating that phosphorylation is inactivating. An examination of cycling cells enriched by elutriation for distinct phases of the cell cycle revealed that BCL-2 was phosphorylated at the G2/M phase of the cell cycle. G2/M-phase cells proved more susceptible to death signals, and phosphorylation of BCL-2 appeared to be responsible, as a Ser70Ala substitution restored resistance to apoptosis. We noted that ASK1 and JNK1 were normally activated at G2/M phase, and JNK was capable of phosphorylating BCL-2. Expression of a series of wild-type and dominant-negative kinases indicated an ASK1/Jun N-terminal protein kinase 1 (JNK1) pathway phosphorylated BCL-2 in vivo. Moreover, the combination of dominant negative ASK1, (dnASK1), dnMKK7, and dnJNK1 inhibited paclitaxel-induced BCL-2 phosphorylation. Thus, stress response kinases phosphorylate BCL-2 during cell cycle progression as a normal physiologic process to inactivate BCL-2 at G2/M.

scholarly journals TRAF Family Proteins Link PKR with NF-κB Activation

2004 ◽  
Vol 24 (10) ◽  
pp. 4502-4512 ◽  
Author(s):  
Jesús Gil ◽  
Maria Angel García ◽  
Paulino Gomez-Puertas ◽  
Susana Guerra ◽  
Joaquín Rullas ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Interaction Model ◽  
Kinase Domain ◽  
Dominant Negative ◽  
Sequence Information ◽  
Physical Interaction ◽  
Dependent Protein Kinase ◽  
Iκb Kinase ◽  
Dependent Protein

ABSTRACT The double-stranded RNA (dsRNA)-dependent protein kinase PKR activates NF-κB via the IκB kinase (IKK) complex, but little is known about additional molecules that may be involved in this pathway. Analysis of the PKR sequence enabled us to identify two putative TRAF-interacting motifs. The viability of such an interaction was further suggested by computer modeling. Here, we present evidence of the colocalization and physical interaction between PKR and TRAF family proteins in vivo, as shown by immunoprecipitation and confocal microscopy experiments. This interaction is induced upon PKR dimerization. Most importantly, we show that the binding between PKR and TRAFs is functionally relevant, as observed by the absence of NF-κB activity upon PKR expression in cells genetically deficient in TRAF2 and TRAF5 or after expression of TRAF dominant negative molecules. On the basis of sequence information and mutational and computer docking analyses, we favored a TRAF-PKR interaction model in which the C-terminal domain of TRAF binds to a predicted TRAF interaction motif present in the PKR kinase domain. Altogether, our data suggest that TRAF family proteins are key components located downstream of PKR that have an important role in mediating activation of NF-κB by the dsRNA-dependent protein kinase.

OPPOSING FUNCTIONS FOR A PROTEIN KINASE: A JNK1 DEPENDENT SWITCH DETERMINES THE ONCOGENIC OR TUMOR SUPPRESSIVE ACTIVITY OF ILK INRHABDOMYOSARCOMA

2008 ◽  
Vol 31 (4) ◽  
pp. 9
Author(s):  
Adam D Durbin ◽  
Gino R Somers ◽  
Michael Forrester ◽  
Gregory E Hannigan ◽  
David Malkin
Keyword(s):  
Protein Kinase ◽  
High Throughput Screening ◽  
Fusion Gene ◽  
Mesenchymal Progenitor Cells ◽  
In Vivo Models ◽  
Primary Tumors ◽  
Multiple Tumor ◽  
Amino Terminal

Background:The integrin-linked kinase (ILK) is a protein kinase involved in the regulation of pathogenic cancer cell behaviours, such as proliferation, survival and invasion. ILK appears to be pro-oncogenic in vitro and in vivo models of tumorigenesis. Rhabdomyosarcoma (RMS) is a primitive mesenchyme-derived tumor and is subclassified into primarily embryonal (ERMS) and alveolar (ARMS) variants. Patients who present with metastatic RMS tumors have a less than 20% chance of cure, suggesting a need to define novel targets for chemotherapeutic intervention. Methods: We used cell culture, murine xenografts and primary human tumors to examine ILK expression and functionality. RNAi and adenoviruses were used to knock down or over expressproteins, and SP600125 was used to inhibit JNK kinase activity. ERMS cells stablye xpressing PAX3-FOXO1A we regenerated using pcDNA3.1 with the full length PAX3-FOXO1A cDNA insert. Results: RNAi-mediated ablation of ILK induced stimulation of ERMS and inhibition of ARMS cell growth in vitro and in vivo. Overexpression of ILK, but not the ILK-R211A mutant reversed these effects. High-throughput screening of multiple tumor cell lines and mesenchymal progenitor cells demonstrated similar ILK anti-growth effects. Consistent with these results, clinical correlations made between ILK immunohistochemical staining intensity and patterns on an ERMS tumor tissue microarray revealed downregulation of ILK in stage III/IV primary tumors. Mechanistically, ILK silencing induced selective phosphorylation of the c-jun amino terminal kinase (JNK) and its target c-Jun in ERMS cells with attenuated phosphorylation in ARMS cells. ERMS cells express higher levels of JNK1 isoforms than ARMS cells. Introduction of the ARMS-associated PAX3-FOXO1A fusion gene into ERMS cells restored the oncogenic function of ILK and downregulated of JNK1. Coupling ILK siRNA with inhibition of the JNK-c-Jun signaling pathway in ERMS cells resulted in growth reductions and apoptotic induction. In contrast, coupling ILK knockdown with overexpression of JNK1 in ARMS cells resulted in growth and c-jun phosphorylation. Conclusion: In summary, these data suggest a model whereby the effect of ILK as an oncogene or tumor suppressor is determined by JNK1. Finally, this data suggests that ILK kinase inhibition may be warranted in ARMS tumors, and may be contraindicated in ERMS.

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