Differential targeting of cPKC and nPKC decodes and regulates Ca2+ and lipid signalling

2014 ◽  
Vol 42 (6) ◽  
pp. 1538-1542 ◽  
Author(s):  
Xin Hui ◽  
Lars Kaestner ◽  
Peter Lipp
Keyword(s):  
Protein Kinases ◽  
Consensus Sequence ◽  
Membrane Targeting ◽  
Cellular Processes ◽  
Lipid Signalling ◽  
Pkc Isoforms

Protein kinases C (PKCs) are ubiquitously expressed and play critical roles in a plethora of physiological and pathophysiological processes. Owing to PKCs’ highly conserved phosphorylation consensus sequence, it has been difficult to distinguish the role of individual PKC isoforms. Recently, the identification of novel membrane targeting via subcellularly targeted diacylglycerol production found for novel PKCs (nPKCs), together with a characterization of their putative functions, has shed new light on the specific roles of individual PKCs in cellular processes.

Characterization of a dual plant protein kinase (FsPK1) up-regulated by abscisic acid and calcium and specifically expressed in dormant seeds ofFagus sylvaticaL.

2003 ◽  
Vol 13 (4) ◽  
pp. 261-271 ◽  
Author(s):  
O. Lorenzo ◽  
C. Nicolás ◽  
G. Nicolás ◽  
D. Rodríguez
Keyword(s):  
Abscisic Acid ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Catalytic Domain ◽  
Consensus Sequence ◽  
Calcium Dependent ◽  
Localization Signal ◽  
Rapid Amplification

An abscisic acid (ABA)-induced cDNA fragment encoding a putative protein kinase (PK) was obtained by differential screening of a cDNA library fromFagus sylvaticaseeds. The full-length clone, named FsPK1, was produced by 5′ rapid amplification of cDNA ends (RACE) extension. This clone contained the 11 catalytic domains present in all protein kinases, but displayed unusual characteristics found only in a few plant PKs. FsPK1 exhibits features of both serine/threonine and tyrosine protein kinases within the catalytic domain, a putative nuclear localization signal within the regulatory domain and the consensus sequence involved in binding of 14-3-3 proteins. The catalytic domain, expressed inEscherichia colias a fusion protein, showed Ca2+-dependentin vitrokinase activity and dual serine/threonine and tyrosine specificity. Transcription of theFsPK1gene was reduced by seed stratification at 4°C, and clearly increased when seeds were treated with 0.1 mM ABA, correlating with the inhibition of germination. Interestingly,FsPK1transcripts were enhanced when ABA (0.1 mM) and calcium (1 mM) were added together, while the addition of EGTA (calcium chelator) and 3,4,5,-trimethoxibenzoic acid 8-(diethylamino) octyl ester (TMB-8, a calcium antagonist) decreased its expression. Furthermore,FsPK1transcript expression was tissue specific and accumulated only in ABA-treated seeds, but not in any ABA-treated vegetative tissues examined. These results suggest that the expression of the corresponding protein could be related to the inhibition of germination mediated by ABA in a calcium-dependent pathway.

scholarly journals From the characterization of the four serine/threonine protein kinases (PknA/B/G/L) ofCorynebacterium glutamicumtoward the role of PknA and PknB inn cell division.

2009 ◽  
Vol 284 (23) ◽  
pp. 16060.2-16060
Author(s):  
Maria Fiuza ◽  
Marc J. Canova ◽  
Isabelle Zanella-Cléon ◽  
Michel Becchi ◽  
Alain J. Cozzone ◽  
...  
Keyword(s):  
Cell Division ◽  
Protein Kinases

NH2 terminus of serum and glucocorticoid-regulated kinase 1 binds to phosphoinositides and is essential for isoform-specific physiological functions

2007 ◽  
Vol 292 (6) ◽  
pp. F1741-F1750 ◽  
Author(s):  
Alan C. Pao ◽  
James A. McCormick ◽  
Hongyan Li ◽  
John Siu ◽  
Cedric Govaerts ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Kinase Activity ◽  
Regulatory Protein ◽  
Forkhead Transcription Factor ◽  
Cellular Processes ◽  
Cellular Compartments ◽  
Stimulation Of

Serum and glucocorticoid regulated kinase 1 (SGK1) has been identified as a key regulatory protein that controls a diverse set of cellular processes including sodium (Na+) homeostasis, osmoregulation, cell survival, and cell proliferation. Two other SGK isoforms, SGK2 and SGK3, have been identified, which differ most markedly from SGK1 in their NH2-terminal domains. We found that SGK1 and SGK3 are potent stimulators of epithelial Na+ channel (ENaC)-dependent Na+ transport, while SGK2, which has a short NH2 terminus, is a weak stimulator of ENaC. Further characterization of the role of the SGK1 NH2 terminus revealed that its deletion does not affect in vitro kinase activity but profoundly limits the ability of SGK1 either to stimulate ENaC-dependent Na+ transport or inhibit Forkhead-dependent gene transcription. The NH2 terminus of SGK1, which shares sequence homology with the phosphoinositide 3-phosphate [PI( 3 )P] binding domain of SGK3, binds phosphoinositides in protein lipid overlay assays, interacting specifically with PI( 3 )P, PI( 4 )P, and PI( 5 )P, but not with PI( 3 , 4 , 5 )P3. Moreover, a point mutation that reduces phosphoinositide binding to the NH2 terminus also reduces SGK1 effects on Na+ transport and Forkhead activity. These data suggest that the NH2 terminus, although not required for PI 3-kinase-dependent modulation of SGK1 catalytic activity, is required for multiple SGK1 functions, including stimulation of ENaC and inhibition of the proapoptotic Forkhead transcription factor. Together, these observations support the idea that the NH2-terminal domain acts downstream of PI 3-kinase-dependent activation to target the kinase to specific cellular compartments and/or substrates, possibly through its interactions with a subset of phosphoinositides.

scholarly journals Generation and Characterization of a New FRET-Based Ca2+ Sensor Targeted to the Nucleus

2021 ◽  
Vol 22 (18) ◽  
pp. 9945
Author(s):  
Luisa Galla ◽  
Nicola Vajente ◽  
Diana Pendin ◽  
Paola Pizzo ◽  
Tullio Pozzan ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Cellular Processes ◽  
A Cell ◽  
Dynamic Concentration ◽  
Subcellular Compartmentalization

Calcium (Ca2+) exerts a pivotal role in controlling both physiological and detrimental cellular processes. This versatility is due to the existence of a cell-specific molecular Ca2+ toolkit and its fine subcellular compartmentalization. Study of the role of Ca2+ in cellular physiopathology greatly benefits from tools capable of quantitatively measuring its dynamic concentration ([Ca2+]) simultaneously within organelles and in the cytosol to correlate localized and global [Ca2+] changes. To this aim, as nucleoplasm Ca2+ changes mirror those of the cytosol, we generated a novel nuclear-targeted version of a Föster resonance energy transfer (FRET)-based Ca2+ probe. In particular, we modified the previously described nuclear Ca2+ sensor, H2BD3cpv, by substituting the donor ECFP with mCerulean3, a brighter and more photostable fluorescent protein. The thorough characterization of this sensor in HeLa cells demonstrated that it significantly improved the brightness and photostability compared to the original probe, thus obtaining a probe suitable for more accurate quantitative Ca2+ measurements. The affinity for Ca2+ was determined in situ. Finally, we successfully applied the new probe to confirm that cytoplasmic and nucleoplasmic Ca2+ levels were similar in both resting conditions and upon cell stimulation. Examples of simultaneous monitoring of Ca2+ signal dynamics in different subcellular compartments in the very same cells are also presented.

scholarly journals From the Characterization of the Four Serine/Threonine Protein Kinases (PknA/B/G/L) ofCorynebacterium glutamicumtoward the Role of PknA and PknB in Cell Division

2008 ◽  
Vol 283 (26) ◽  
pp. 18099-18112 ◽  
Author(s):  
Maria Fiuza ◽  
Marc J. Canova ◽  
Isabelle Zanella-Cléon ◽  
Michel Becchi ◽  
Alain J. Cozzone ◽  
...  
Keyword(s):  
Cell Division ◽  
Protein Kinases

scholarly journals Involvement of Rac/Cdc42/PAK pathway in cytoskeletal rearrangements.

2009 ◽  
Vol 56 (2) ◽  
Author(s):  
Joanna Szczepanowska
Keyword(s):  
Neurodegenerative Diseases ◽  
Protein Kinases ◽  
Small Gtpases ◽  
Cytoskeletal Reorganization ◽  
Cellular Processes ◽  
Cytoskeletal Structure ◽  
Binding Partners ◽  
Evolutionarily Conserved ◽  
Cytoskeletal Rearrangements

The p21-activated kinases (PAKs) are serine/threonine protein kinases interacting with small GTPases - Rac and Cdc42. PAKs are found in most eukaryotes and play an evolutionarily conserved role in many cellular processes. Six human PAKs have been identified, and based on homology, they can be classified into two groups. This review focuses specifically on the role of Rac/Cdc42 regulated PAKs in maintaining and remodeling cytoskeletal structure in various organisms. A list of PAKs substrates and binding partners implicated directly and indirectly in cytoskeletal reorganization is presented. Also perturbations of the Rac/Cdc42/PAK pathway leading to tumorigenesis and neurodegenerative diseases are reviewed.

scholarly journals Structural characterization of human Vaccinia-Related Kinases (VRK) bound to small-molecule inhibitors identifies different P-loop conformations

2017 ◽  
Author(s):  
Rafael M. Couñago ◽  
Charles K. Allerston ◽  
Pavel Savitsky ◽  
Hatylas Azevedo ◽  
Paulo H. Godoi ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Related Protein ◽  
Chemical Probes ◽  
Cellular Processes ◽  
Starting Point ◽  
Loop Conformations ◽  
Potential Use ◽  
Specific Inhibitors

ABSTRACTThe human genome encodes two active Vaccinia-related protein kinases (VRK), VRK1 and VRK2. These proteins have been implicated in a number of cellular processes and linked to a variety of tumors. However, understanding the cellular role of VRKs and establishing their potential use as targets for therapeutic intervention has been limited by the lack of tool compounds that can specifically modulate the activity of these kinases in cells. Here we identified BI-D1870, a dihydropteridine inhibitor of RSK kinases, as a promising starting point for the development of chemical probes targeting the active VRKs. We solved co-crystal structures of both VRK1 and VRK2 bound to BI-D1870 and of VRK1 bound to two broad-spectrum inhibitors. These structures revealed that both VRKs can adopt a P-loop folded conformation, which is stabilized by different mechanisms on each protein. Based on these structures, we suggest modifications to the dihydropteridine scaffold that can be explored to produce potent and specific inhibitors towards VRK1 and VRK2.

Cloning and characterization of an extremely conserved satellite DNA family from the root-knot nematode Meloidogyne arenaria

Genome ◽  
2000 ◽  
Vol 43 (2) ◽  
pp. 346-353 ◽  
Author(s):  
Philippe Castagnone-Sereno ◽  
Frédéric Leroy ◽  
Pierre Abad
Keyword(s):  
Satellite Dna ◽  
Potential Role ◽  
Genomic Organization ◽  
Consensus Sequence ◽  
Meloidogyne Arenaria ◽  
Root Knot Nematode ◽  
Phytoparasitic Nematode ◽  
Nematode Genome

A new satellite DNA family, named pMaE, has been cloned from the genome of the phytoparasitic nematode, Meloidogyne arenaria (Nematoda: Tylenchida). It is represented as tandemly repeated sequences with a monomeric unit of 172 bp. The monomers are present at approximately 15 700 copies per haploid genome, and represent about 5.3% of the total genomic DNA. Twenty-seven independent monomers have been cloned and sequenced. The deduced consensus sequence is 70.9% A + T rich, with frequent stretches of A and (or) T. Several direct or inverted sub-repeats are present in the sequence, which may allow the formation of a dyad structure, suggesting some potential role of this repetitive sequence in heterochromatin condensation. The monomers are very homogeneous in sequence, showing on average 1.8% divergence from their consensus sequence. Moreover, Southern blot experiments and sequence analysis of homologous monomers from the genome of geographically distinct M. arenaria populations have shown that this satellite DNA is uniformly distributed and highly conserved within the species. Therefore, it is hypothesized that this unusually low level of variability, either within the genome of a given population or between populations, could be achieved as the result of some highly effective homogenization mechanism acting upon the nematode genome. Key words: genomic organization, Meloidogyne arenaria, satellite DNA.

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