Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.11.1 (protein kinase)
81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The EL2 gene of rice (Oryza sativa), previously classified as early response gene against the potent biotic elicitor N-acetylchitoheptaose and encoding a short polypeptide with unknown function, was identified as a novel cell cycle regulatory gene related to the recently reported SIAMESE (SIM) gene of Arabidopsis thaliana. Iterative two-hybrid screens, in vitro pull-down assays, and fluorescence resonance energy transfer analyses showed that Orysa; EL2 binds the cyclin-dependent kinase (CDK) CDKA1;1 and D-type cyclins. No interaction was observed with the plant-specific B-type CDKs. The amino acid motif ELERFL was identified to be essential for cyclin, but not for CDK binding. Orysa;EL2 impaired the ability of Orysa; CYCD5;3 to complement a budding yeast (Saccharomyces cerevisiae) triple CLN mutant, whereas recombinant protein inhibited CDK activity in vitro. Moreover, Orysa;EL2 was able to rescue the multicellular trichome phenotype of sim mutants of Arabidopsis, unequivocally demonstrating that Orysa;EL2 operates as a cell cycle inhibitor. Orysa;EL2 mRNA levels were induced by cold, drought, and propionic acid. Our data suggest that Orysa;EL2 encodes a new type of plant CDK inhibitor that links cell cycle progression with biotic and abiotic stress responses.
...
PMID:Novel plant-specific cyclin-dependent kinase inhibitors induced by biotic and abiotic stresses. 1759 8

Pyruvate, orthophosphate dikinase (PPDK) is a ubiquitous, low-abundance metabolic enzyme of undetermined function in C3 plants. Its activity in C3 chloroplasts is light-regulated via reversible phosphorylation of an active-site Thr residue by the PPDK regulatory protein (RP), a most unusual bifunctional protein kinase (PK)/protein phosphatase (PP). In this paper we document the molecular cloning and functional analysis of the two unique C3 RPs in Arabidopsis thaliana. The first of these, AtRP1, encodes a typical chloroplast-targeted, bifunctional C4-like RP. The second RP gene, AtRP2, encodes a monofunctional polypeptide that possesses in vitro RP-like PK activity but lacks PP activity, and is localized in the cytosol. Notably, the deduced primary structures of these two highly homologous polypeptides are devoid of any canonical subdomain structure that unifies all known eukaryotic and prokaryotic Ser/Thr PKs into one of three superfamilies, despite the direct demonstration that AtRP1 is functionally a member of this group. Instead, these C3 RPs and the related C4 plant homologues encode a conserved, centrally positioned, approximately 260-residue sequence currently described as the 'domain of unknown function 299' (DUF 299). We propose that vascular plant RPs form a unique protein kinase family now designated as the DUF 299 gene family.
...
PMID:The pyruvate, orthophosphate dikinase regulatory proteins of Arabidopsis possess a novel, unprecedented Ser/Thr protein kinase primary structure. 1799 18

Flagellate green algae have developed a visual system, the eyespot apparatus, which allows the cell to phototax. In a recent proteomic approach, we identified 202 proteins from a fraction enriched in eyespot apparatuses of Chlamydomonas reinhardtii. Among these proteins, five protein kinases and two protein phosphatases were present, indicating that reversible protein phosphorylation occurs in the eyespot. About 20 major phosphoprotein bands were detected in immunoblots of eyespot proteins with an anti-phosphothreonine antibody. Toward the profiling of the targets of protein kinases in the eyespot fraction, we analyzed its phosphoproteome. The solubilized proteins of the eyespot fraction were treated with the endopeptidases LysC and trypsin prior to enrichment of phosphopeptides with immobilized metal-ion affinity chromatography. Phosphopeptides were analyzed by nano-liquid chromatography-electrospray ionization-mass spectrometry (MS) with MS/MS as well as neutral-loss-triggered MS/MS/MS spectra. We were able to identify 68 different phosphopeptides along with 52 precise in vivo phosphorylation sites corresponding to 32 known proteins of the eyespot fraction. Among the identified phosphoproteins are enzymes of carotenoid and fatty acid metabolism, putative signaling components, such as a SOUL heme-binding protein, a Ca(2+)-binding protein, and an unusual protein kinase, but also several proteins with unknown function. Notably, two unique photoreceptors, channelrhodopsin-1 and channelrhodopsin-2, contain three and one phosphorylation sites, respectively. Phosphorylation of both photoreceptors occurs in the cytoplasmatic loop next to their seven transmembrane regions in a similar distance to that observed in vertebrate rhodopsins, implying functional importance for regulation of these directly light-gated ion channels relevant for the photoresponses of C. reinhardtii.
...
PMID:The phosphoproteome of a Chlamydomonas reinhardtii eyespot fraction includes key proteins of the light signaling pathway. 1806 59

The subcellular distribution of kinases and other signaling proteins is regulated in response to cellular cues; however, the extent of this regulation has not been investigated for any gene set in any organism. Here, we present a systematic analysis of protein kinases in the budding yeast, screening for differential localization during filamentous growth. Filamentous growth is an important stress response involving mitogen-activated protein kinase and cAMP-dependent protein kinase signaling modules, wherein yeast cells form interconnected and elongated chains. Because standard strains of yeast are nonfilamentous, we constructed a unique set of 125 kinase-yellow fluorescent protein chimeras in the filamentous Sigma1278b strain for this study. In total, we identified six cytoplasmic kinases (Bcy1p, Fus3p, Ksp1p, Kss1p, Sks1p, and Tpk2p) that localize predominantly to the nucleus during filamentous growth. These kinases form part of an interdependent, localization-based regulatory network: deletion of each individual kinase, or loss of kinase activity, disrupts the nuclear translocation of at least two other kinases. In particular, this study highlights a previously unknown function for the kinase Ksp1p, indicating the essentiality of its nuclear translocation during yeast filamentous growth. Thus, the localization of Ksp1p and the other kinases identified here is tightly controlled during filamentous growth, representing an overlooked regulatory component of this stress response.
...
PMID:Analysis of the yeast kinome reveals a network of regulated protein localization during filamentous growth. 1841 10

Eukaryotic GCN5 acetyltransferases influence diverse biological processes by acetylating histones and non-histone proteins and regulating chromatin and gene-specific transcription as part of multiprotein complexes. In lower eukaryotes and invertebrates, these complexes include the yeast ADA complex that is still incompletely understood; the SAGA (Spt-Ada-Gcn5 acetylase) complexes from yeast to Drosophila that are mostly coactivators; and the ATAC (Ada Two-A containing) complex, only known in Drosophila and still poorly characterized. In contrast, vertebrate organisms, express two paralogous GCN5-like acetyltransferases (GCN5 and PCAF), which have been found so far only in SAGA-type complexes referred to hereafter as the STAGA (SPT3-TAF9-GCN5/PCAF acetylase) complexes. We now report the purification and characterization of vertebrate (human) ATAC-type complexes and identify novel components of STAGA. We show that human ATAC complexes incorporate in addition to GCN5 or PCAF (GCN5/PCAF), other epigenetic coregulators (ADA2-A, ADA3, STAF36, and WDR5), cofactors of chromatin assembly/remodeling and DNA replication machineries (POLE3/CHRAC17 and POLE4), the stress- and TGFbeta-activated protein kinase (TAK1/MAP3K7) and MAP3-kinase regulator (MBIP), additional cofactors of unknown function, and a novel YEATS2-NC2beta histone fold module that interacts with the TATA-binding protein (TBP) and negatively regulates transcription when recruited to a promoter. We further identify the p38 kinase-interacting protein (p38IP/FAM48A) as a novel component of STAGA with distant similarity to yeast Spt20. These results suggest that vertebrate ATAC-type and STAGA-type complexes link specific extracellular signals to modification of chromatin structure and regulation of the basal transcription machinery.
...
PMID:Human ATAC Is a GCN5/PCAF-containing acetylase complex with a novel NC2-like histone fold module that interacts with the TATA-binding protein. 1883 86

In Saccharomyces cerevisiae, Cdc13 binds telomeric DNA to recruit telomerase and to "cap" chromosome ends. In temperature-sensitive cdc13-1 mutants telomeric DNA is degraded and cell-cycle progression is inhibited. To identify novel proteins and pathways that cap telomeres, or that respond to uncapped telomeres, we combined cdc13-1 with the yeast gene deletion collection and used high-throughput spot-test assays to measure growth. We identified 369 gene deletions, in eight different phenotypic classes, that reproducibly demonstrated subtle genetic interactions with the cdc13-1 mutation. As expected, we identified DNA damage checkpoint, nonsense-mediated decay and telomerase components in our screen. However, we also identified genes affecting casein kinase II activity, cell polarity, mRNA degradation, mitochondrial function, phosphate transport, iron transport, protein degradation, and other functions. We also identified a number of genes of previously unknown function that we term RTC, for restriction of telomere capping, or MTC, for maintenance of telomere capping. It seems likely that many of the newly identified pathways/processes that affect growth of budding yeast cdc13-1 mutants will play evolutionarily conserved roles at telomeres. The high-throughput spot-testing approach that we describe is generally applicable and could aid in understanding other aspects of eukaryotic cell biology.
...
PMID:A genomewide suppressor and enhancer analysis of cdc13-1 reveals varied cellular processes influencing telomere capping in Saccharomyces cerevisiae. 1884 48

The Drosophila Swiss Cheese (SWS) protein and its vertebrate ortholog Neuropathy Target Esterase (NTE) are required for neuronal survival and glial integrity. In humans, NTE is the target of organophosphorous compounds which cause a paralyzing axonal degeneration and recently mutations in NTE have been shown to cause a Hereditary Spastic Paraplegia called NTE-related Motor-Neuron Disorder. SWS and NTE are concentrated in the endoplasmic reticulum and both have been shown to have an esterase function against an artificial substrate. However, the functional mechanisms and the pathways in which SWS/NTE are involved in are still widely unknown. Here, we show that SWS interacts specifically with the C3 catalytic subunit of cAMP activated protein kinase (PKA-C3), which together with orthologs in mouse (Pkare) and human (PrKX) forms a novel class of catalytic subunits of unknown function. This interaction requires a domain of SWS which shows homology to regulatory subunits of PKA and, like conventional regulatory subunits, the binding of SWS to the PKA-C3 inhibits its function. Consistent with this result, expression of additional PKA-C3 induces degeneration and enhances the neurodegenerative phenotype in sws mutants. We also show that the complex formation with the membrane-bound SWS tethers PKA-C3 to membranes. We therefore propose a model in which SWS acts as a noncanonical subunit for PKA-C3, whereby the complex formation regulates the localization and kinase activity of PKA-C3, and that disruption of this regulation can induce neurodegeneration.
...
PMID:Swiss Cheese, a protein involved in progressive neurodegeneration, acts as a noncanonical regulatory subunit for PKA-C3. 1894 96

Thylakoid-soluble phosphoprotein of 9 kDa, TSP9, is an intrinsically unstructured plant-specific protein [Song, J., et al. (2006) Biochemistry 45, 15633-15643] with unknown function but established associations with light-harvesting proteins and peripheries of both photosystems [Hansson, M., et al. (2007) J. Biol. Chem. 282, 16214-16222]. To investigate the function of this protein, we used a combination of reverse genetics and biochemical and fluorescence measurement methods in Arabidopsis thaliana. Differential gene expression analysis of plants with a T-DNA insertion in the TSP9 gene using an array of 24000 Arabidopsis genes revealed disappearance of high light-dependent induction of a specific set of mostly signaling and unknown proteins. TSP9-deficient plants had reduced levels of in vivo phosphorylation of light-harvesting complex II polypeptides. Recombinant TSP9 was phosphorylated in light by thylakoid membranes isolated from the wild-type and mutant plants lacking STN8 protein kinase but not by the thylakoids deficient in STN7 kinase, essential for photosynthetic state transitions. TSP9-lacking mutant and RNAi plants with downregulation of TSP9 showed reduced ability to perform state transitions. The nonphotochemical quenching of chlorophyll fluorescence at high light intensities was also less efficient in the mutant compared to wild-type plants. Blue native electrophoresis of thylakoid membrane protein complexes revealed that TSP9 deficiency increased relative stability of photosystem II dimers and supercomplexes. It is concluded that TSP9 regulates plant light harvesting acting as a membrane-binding protein facilitating dissociation of light-harvesting proteins from photosystem II.
...
PMID:Intrinsically unstructured phosphoprotein TSP9 regulates light harvesting in Arabidopsis thaliana. 1911 38

The clinical syndrome of heart failure is associated with both a resting vasoconstriction and reduced sensitivity to nitric oxide mediated vasodilatation, and this review will focus on the role of myosin light chain (MLC) phosphatase in the pathogenesis of the vascular abnormalities of heart failure. Nitric oxide mediates vasodilatation by an activation of guanylate cyclase and an increase in the production of cGMP, which leads to the activation of the type I cGMP-dependent protein kinase (PKGI). PKGI then activates a number of targets that produce smooth muscle relaxation including MLC phosphatase. MLC phosphatase is a holoenzyme consisting of three subunits; a 20 kD subunit of unknown function, an approximately 38-kD catalytic subunit and a myosin targeting subunit (MYPT1). Alternative splicing of a 31 bp 3 exon generates MYPT1 isoforms, which differ by a COOH-terminus leucine zipper (LZ). Further, PKGI-mediated activation of MLC phosphatase requires the expression of a LZ+ MYPT1. Congestive heart failure is associated with a decrease in LZ+ MYPT1 expression, which results in a decrease in the sensitivity to cGMP-mediated smooth muscle relaxation. Beyond their ability to reduce afterload, angiotensin converting enzyme (ACE) inhibitors have a number of beneficial effects that include maintaining the expression of the LZ+ MYPT1 isoform, thereby conserving normal sensitivity to cGMP-mediated vasodilatation, as well as differentially regulating genes associated with mitogen activated protein kinase (MAPK) signalling. ACE inhibition reduces circulating angiotensin II and thus limits the downstream activation of MAPK signalling pathways, possibly preventing the alteration of the vascular phenotype to preserve normal vascular function.
...
PMID:The potential role of MLC phosphatase and MAPK signalling in the pathogenesis of vascular dysfunction in heart failure. 1912 Jul

Recent efforts have underlined the role of serine/threonine protein kinases in growth, pathogenesis, and cell wall metabolism in Mycobacterium tuberculosis. Although most kinases have been investigated for their physiological roles, little information is available regarding how serine/threonine protein kinase-dependent phosphorylation regulates the activity of kinase substrates. Herein, we focused on M. tuberculosis Rv2175c, a protein of unknown function, conserved in actinomycetes, and recently identified as a substrate of the PknL kinase. We solved the solution structure of Rv2175c by multidimensional NMR and demonstrated that it possesses an original winged helix-turn-helix motif, indicative of a DNA-binding protein. The DNA-binding activity of Rv2175c was subsequently confirmed by fluorescence anisotropy, as well as in electrophoretic mobility shift assays. Mass spectrometry analyses using a combination of MALDI-TOF and LC-ESI/MS/MS identified Thr(9) as the unique phosphoacceptor. This was further supported by complete loss of PknL-dependent phosphorylation of an Rv2175c_T9A mutant. Importantly, the DNA-binding activity was completely abrogated in a Rv2175c_T9D mutant, designed to mimic constitutive phosphorylation, but not in a mutant lacking the first 13 residues. This implies that the function of the N-terminal extension is to provide a phosphoacceptor (Thr(9)), which, following phosphorylation, negatively regulates the Rv2175c DNA-binding activity. Interestingly, the N-terminal disordered extension, which bears the phosphoacceptor, was found to be restricted to members of the M. tuberculosis complex, thus suggesting the existence of an original mechanism that appears to be unique to the M. tuberculosis complex.
...
PMID:The Mycobacterium tuberculosis Ser/Thr kinase substrate Rv2175c is a DNA-binding protein regulated by phosphorylation. 1945 63


<< Previous 1 2 3 4 5 6 7 8 9 10

---