scholarly journals Membrane-mediated dimerization potentiates PIP5K lipid kinase activity

2021 ◽  
Author(s):  
Scott D Hansen ◽  
Albert A Lee ◽  
Jay T Groves
Keyword(s):  
Kinase Activity ◽  
Dynamic Range ◽  
Critical Role ◽  
Catalytic Efficiency ◽  
Receptor Activation ◽  
Kinase Domain ◽  
Dependent Manner ◽  
Stochastic Variation ◽  
Lipid Kinase ◽  
Broad Dynamic Range

The phosphatidylinositol 4-phosphate 5-kinase (PIP5K) family of lipid modifying enzymes generate the majority of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) lipids found at the plasma membrane in eukaryotic cells. PI(4,5)P2 lipids serve a critical role in regulating receptor activation, ion channel gating, endocytosis, and actin nucleation. Here we describe how PIP5K activity is regulated by cooperative binding to PI(4,5)P2 lipids and membrane-mediated dimerization of the kinase domain. In contrast to constitutively dimeric phosphatidylinositol 5-phosphate 4-kinase (PIP4K, type II PIPK), solution PIP5K exists in a weak monomer-dimer equilibrium. PIP5K monomers can associate with PI(4,5)P2 containing membranes and dimerize in a protein density dependent manner. Although dispensable for PI(4,5)P2 binding and lipid kinase activity, dimerization enhances the catalytic efficiency of PIP5K through a mechanism consistent with allosteric regulation. Additionally, dimerization amplifies stochastic variation in the kinase reaction velocity and strengthens effects such as the recently described stochastic geometry sensing. Overall, the mechanism of PIP5K membrane binding creates a broad dynamic range of lipid kinase activities that are coupled to the density of PI(4,5)P2 and membrane bound kinase.

scholarly journals The binding of NCAM to FGFR1 induces a specific cellular response mediated by receptor trafficking

2009 ◽  
Vol 187 (7) ◽  
pp. 1101-1116 ◽  
Author(s):  
Chiara Francavilla ◽  
Paola Cattaneo ◽  
Vladimir Berezin ◽  
Elisabeth Bock ◽  
Diletta Ami ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cellular Response ◽  
Critical Role ◽  
Biological Significance ◽  
Receptor Activation ◽  
Dependent Manner ◽  
Fgf Receptor ◽  
Neural Cell Adhesion ◽  
Sustained Activation

Neural cell adhesion molecule (NCAM) associates with fibroblast growth factor (FGF) receptor-1 (FGFR1). However, the biological significance of this interaction remains largely elusive. In this study, we show that NCAM induces a specific, FGFR1-mediated cellular response that is remarkably different from that elicited by FGF-2. In contrast to FGF-induced degradation of endocytic FGFR1, NCAM promotes the stabilization of the receptor, which is recycled to the cell surface in a Rab11- and Src-dependent manner. In turn, FGFR1 recycling is required for NCAM-induced sustained activation of various effectors. Furthermore, NCAM, but not FGF-2, promotes cell migration, and this response depends on FGFR1 recycling and sustained Src activation. Our results implicate NCAM as a nonconventional ligand for FGFR1 that exerts a peculiar control on the intracellular trafficking of the receptor, resulting in a specific cellular response. Besides introducing a further level of complexity in the regulation of FGFR1 function, our findings highlight the link of FGFR recycling with sustained signaling and cell migration and the critical role of these events in dictating the cellular response evoked by receptor activation.

scholarly journals Pie1, a Protein Interacting with Mec1, Controls Cell Growth and Checkpoint Responses in Saccharomyces cerevisiae

2001 ◽  
Vol 21 (3) ◽  
pp. 755-764 ◽  
Author(s):  
Tatsushi Wakayama ◽  
Tae Kondo ◽  
Seiko Ando ◽  
Kunihiro Matsumoto ◽  
Katsunori Sugimoto
Keyword(s):  
Dna Damage ◽  
Cell Growth ◽  
Kinase Activity ◽  
Critical Role ◽  
Kinase Domain ◽  
Protein Kinase Activity ◽  
Replication Checkpoint ◽  
Family Protein ◽  
Replication Block

ABSTRACT In eukaryotes, the ATM and ATR family proteins play a critical role in the DNA damage and replication checkpoint controls. These proteins are characterized by a kinase domain related to the phosphatidylinositol 3-kinase, but they have the ability to phosphorylate proteins. In budding yeast, the ATR family protein Mec1/Esr1 is essential for checkpoint responses and cell growth. We have isolated the PIE1 gene in a two-hybrid screen for proteins that interact with Mec1, and we show that Pie1 interacts physically with Mec1 in vivo. Like MEC1, PIE1is essential for cell growth, and deletion of the PIE1 gene causes defects in the DNA damage and replication block checkpoints similar to those observed in mec1Δ mutants. Rad53 hyperphosphorylation following DNA damage and replication block is also decreased in pie1Δ cells, as in mec1Δcells. Pie1 has a limited homology to fission yeast Rad26, which forms a complex with the ATR family protein Rad3. Mutation of the region in Pie1 homologous to Rad26 results in a phenotype similar to that of thepie1Δ mutation. Mec1 protein kinase activity appears to be essential for checkpoint responses and cell growth. However, Mec1 kinase activity is unaffected by the pie1Δ mutation, suggesting that Pie1 regulates some essential function other than Mec1 kinase activity. Thus, Pie1 is structurally and functionally related to Rad26 and interacts with Mec1 to control checkpoints and cell proliferation.

scholarly journals Heterotrimeric G-protein shuttling via Gip1 extends the dynamic range of eukaryotic chemotaxis

2016 ◽  
Vol 113 (16) ◽  
pp. 4356-4361 ◽  
Author(s):  
Yoichiro Kamimura ◽  
Yukihiro Miyanaga ◽  
Masahiro Ueda
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Dynamic Range ◽  
Protein Translocation ◽  
Receptor Activation ◽  
Dependent Manner ◽  
Heterotrimeric G Protein ◽  
Range Sensing ◽  
Interacting Protein ◽  
Wide Range

Chemotactic eukaryote cells can sense chemical gradients over a wide range of concentrations via heterotrimeric G-protein signaling; however, the underlying wide-range sensing mechanisms are only partially understood. Here we report that a novel regulator of G proteins, G protein-interacting protein 1 (Gip1), is essential for extending the chemotactic range of Dictyostelium cells. Genetic disruption of Gip1 caused severe defects in gradient sensing and directed cell migration at high but not low concentrations of chemoattractant. Also, Gip1 was found to bind and sequester G proteins in cytosolic pools. Receptor activation induced G-protein translocation to the plasma membrane from the cytosol in a Gip1-dependent manner, causing a biased redistribution of G protein on the membrane along a chemoattractant gradient. These findings suggest that Gip1 regulates G-protein shuttling between the cytosol and the membrane to ensure the availability and biased redistribution of G protein on the membrane for receptor-mediated chemotactic signaling. This mechanism offers an explanation for the wide-range sensing seen in eukaryotic chemotaxis.

scholarly journals p90 ribosomal S6 kinase 2 is associated with and dephosphorylated by protein phosphatase 2Cδ

2004 ◽  
Vol 382 (2) ◽  
pp. 425-431 ◽  
Author(s):  
Ulrik DOEHN ◽  
Steen GAMMELTOFT ◽  
Shi-Hsiang SHEN ◽  
Claus J. JENSEN
Keyword(s):  
Protein Phosphatase ◽  
Kinase Activity ◽  
Kinase Domain ◽  
Protein Kinase Activity ◽  
Dependent Manner ◽  
S6 Kinase ◽  
Ribosomal S6 Kinase 2 ◽  
P90 Ribosomal S6 Kinase ◽  
Ribosomal S6 Kinase

RSK2 (p90 ribosomal S6 kinase 2) is activated via the ERK (extracellular-signal-regulated kinase) pathway by phosphorylation on four sites: Ser227 in the activation loop of the N-terminal kinase domain, Ser369 in the linker, Ser386 in the hydrophobic motif and Thr577 in the C-terminal kinase domain of RSK2. In the present study, we demonstrate that RSK2 is associated in vivo with PP2Cδ (protein phosphatase 2Cδ). In epidermal growth factorstimulated cells, RSK2 is partially dephosphorylated on all four sites in an Mn2+-dependent manner, leading to reduced protein kinase activity. Furthermore, PP2Cδ is phosphorylated by ERK on Thr315 and Thr333 in the catalytic domain. Mutation of Thr315 and Thr333 to alanine in a catalytically inactive mutant PP2Cδ(H154D) (His154→Asp) increases the association with RSK2 significantly, whereas mutation to glutamate, mimicking phosphorylation, reduces the binding of RSK2. The domains of interaction are mapped to the N-terminal extension comprising residues 1–71 of PP2Cδ and the N-terminal kinase domain of RSK2. The interaction is specific, since PP2Cδ associates with RSK1–RSK4, MSK1 (mitogen- and stress-activated kinase 1) and MSK2, but not with p70 S6 kinase or phosphoinositide-dependent kinase 1. We conclude that RSK2 is associated with PP2Cδ in vivo and is partially dephosphorylated by it, leading to reduced kinase activity.

scholarly journals Mutation of the polo-box disrupts localization and mitotic functions of the mammalian polo kinase Plk

1998 ◽  
Vol 95 (16) ◽  
pp. 9301-9306 ◽  
Author(s):  
Kyung S. Lee ◽  
Tallessyn Z. Grenfell ◽  
Frederic R. Yarm ◽  
Raymond L. Erikson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Proliferation ◽  
Protein Kinases ◽  
Kinase Activity ◽  
Critical Role ◽  
Kinase Domain ◽  
Temperature Sensitive ◽  
Conserved Sequence ◽  
Spindle Poles ◽  
Polo Kinase

Members of the polo subfamily of protein kinases play pivotal roles in cell proliferation. In addition to the kinase domain, polo kinases have a strikingly conserved sequence in the noncatalytic domain, termed the polo-box. The function of the polo-box is currently undefined. The mammalian polo-like kinase Plk is a functional homologue ofSaccharomyces cerevisiaeCdc5. Here, we show that Plk localizes at the spindle poles and cytokinetic neck filaments. Without impairing kinase activity, a conservative mutation in the polo-box disrupts the capacity of Plk to complement the defect associated with acdc5–1temperature-sensitive mutation and to localize to these subcellular structures. Our data provide evidence that the polo-box plays a critical role in Plk function, likely by directing its subcellular localization.

scholarly journals Necroptotic astrocytes contribute to maintaining stemness of disseminated medulloblastoma through CCL2 secretion

2019 ◽  
Vol 22 (5) ◽  
pp. 625-638 ◽  
Author(s):  
Hailong Liu ◽  
Youliang Sun ◽  
Jenny A O’Brien ◽  
Janusz Franco-Barraza ◽  
Xueling Qi ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Critical Role ◽  
Notch Pathway ◽  
Prognostic Indicator ◽  
Kinase Domain ◽  
Janus Kinase ◽  
Dependent Manner ◽  
Primary Therapy ◽  
Essential Components ◽  
Signaling Activation

Abstract Background Medulloblastoma (MB) with metastases at diagnosis and recurrence correlates with poor prognosis. Unfortunately, the molecular mechanism underlying metastases growth has received less attention than primary therapy-naïve MB. Though astrocytes have been frequently detected in brain tumors, their roles in regulating the stemness properties of MB stem-like cells (MBSCs) in disseminated lesions remain elusive. Methods Effects of tumor-associated astrocyte (TAA)–secreted chemokine C-C ligand 2 (CCL2) on MBSC self-renewal was determined by immunostaining analysis. Necroptosis of TAA was examined by measuring necrosome activity. Alterations in Notch signaling were examined after inhibition of CCL2. Progression of MBSC-derived tumors was evaluated after pharmaceutical blockage of necroptosis. Results TAA, as the essential components of disseminated tumor, produced high levels of CCL2 to shape the inflammation microenvironment, which stimulated the enrichment of MBSCs in disseminated MB. In particular, CCL2 played a pivotal role in maintaining stem-like properties via Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3)–mediated activation of Notch signaling. Loss of CCL2/C-C chemokine receptor 2 (CCR2) function repressed the JAK2/STAT3-Notch pathway and impaired MBSC proliferation, leading to a dramatic reduction of stemness, tumorigenicity, and metastasizing capability. Furthermore, necroptosis-induced CCL2 release depended on activation of receptor-interacting protein 1 (RIP1)/RIP3/mixed lineage kinase domain-like pseudokinase (MLKL) in TAA, which promoted the oncogenic phenotype. Blockade of necroptosis resulted in CCL2 deprivation and compromised MBSC self-proliferation, indicating MBSCs outsourced CCL2 from necroptotic TAA. Finally, CCL2 was upregulated in high-risk stages of MB, further supporting its value as a prognostic indicator. Conclusion These findings highlighted the critical role of CCL2/CCR2 in Notch signaling activation in MBSCs and revealed a necroptosis-associated glial cytokine microenvironment driving stemness maintenance in disseminations. Key Points 1. TAA-derived CCL2 promoted stemness in disseminated MBSCs through Notch signaling activation via the JAK2/STAT3 pathway. 2. TAA released CCL2 in a RIP1/RIP3/MLKL-dependent manner leading to necroptosis.

scholarly journals A highly efficient peptide substrate for EGFR activates the kinase by inducing aggregation

2013 ◽  
Vol 453 (3) ◽  
pp. 337-344 ◽  
Author(s):  
Kate Engel ◽  
Tomoaki Sasaki ◽  
Qi Wang ◽  
John Kuriyan
Keyword(s):  
Kinase Activity ◽  
Growth Factor Receptor ◽  
Catalytic Efficiency ◽  
Kinase Domain ◽  
Receptor Kinase ◽  
Peptide Substrate ◽  
Peptide Substrates ◽  
Epidermal Growth ◽  
Asymmetric Dimer ◽  
Egfr Kinase

Formation of an asymmetric dimer by the EGFR (epidermal growth factor receptor) kinase domains results in allosteric activation. Since this dimer does not readily form in solution, the EGFR kinase domain phosphorylates most peptide substrates with a relatively low catalytic efficiency. Peptide C is a synthetic peptide substrate of EGFR developed by others that is phosphorylated with a significantly higher catalytic efficiency, and we sought to understand the basis for this. Peptide C was found to increase EGFR kinase activity by promoting formation of the EGFR kinase domain asymmetric dimer. Activation of the kinase domain by Peptide C also enhances phosphorylation of other substrates. Aggregation of the EGFR kinase domain by Peptide C probably underlies activation, and Peptide C precipitates several other proteins. Peptide C was found to form fibrils independent of the presence of EGFR, and these fibrils may facilitate aggregation and activation of the kinase domain. These results establish that a peptide substrate of EGFR may increase catalytic activity by promoting kinase domain dimerization by an aggregation-mediated mechanism.

scholarly journals MAP3K4 Kinase Activity Dependent Control of Mouse Gonadal Sex Determination†

2021 ◽  
Author(s):  
Noha A M Shendy ◽  
Amber L Broadhurst ◽  
Kristin Shoemaker ◽  
Robert Read ◽  
Amy N Abell
Keyword(s):  
Sex Determination ◽  
Kinase Activity ◽  
Critical Role ◽  
Reproductive Organs ◽  
Kinase Domain ◽  
Sex Reversal ◽  
Functional Protein ◽  
Protein Protein Interaction ◽  
Ovarian Size ◽  
Additional Protein

Abstract Sex determination requires the commitment of bipotential gonads to either a testis or ovarian fate. Gene deletion of the kinase Map3k4 results in gonadal sex reversal in XY mice, and transgenic re-expression of Map3k4 rescues the sex reversal phenotype. Map3k4 encodes a large, multi-functional protein possessing a kinase domain and several, additional protein-protein interaction domains. Although MAP3K4 plays a critical role in male gonadal sex determination, it is unknown if the kinase activity of MAP3K4 is required. Here, we use mice expressing full-length, kinase-inactive MAP3K4 from the endogenous Map3k4 locus to examine the requirement of MAP3K4 kinase activity in sex determination. Although homozygous kinase-inactivation of MAP3K4 (Map3k4KI/KI) is lethal, a small fraction survive to adulthood. We show Map3k4KI/KI adults exhibit a 4:1 female-biased sex ratio. Many adult Map3k4KI/KI phenotypic females have a Y chromosome. XY Map3k4KI/KI adults with sex reversal display female mating behavior, but do not give rise to offspring. Reproductive organs are overtly female, but there is a broad spectrum of ovarian phenotypes, including ovarian absence, primitive ovaries, reduced ovarian size, and ovaries having follicles in all stages of development. Further, XY Map3k4KI/KI adults are smaller than either male or female Map3k4WT/WT mice. Examination of the critical stage of gonadal sex determination at E11.5 shows that loss of MAP3K4 kinase activity results in the loss of Sry expression in XY Map3k4KI/KI embryos, indicating embryonic male gonadal sex reversal. Together, these findings demonstrate the essential role for kinase activity of MAP3K4 in male gonadal sex determination.

scholarly journals Architecture and dynamics of the autophagic phosphatidylinositol 3-kinase complex

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Sulochanadevi Baskaran ◽  
Lars-Anders Carlson ◽  
Goran Stjepanovic ◽  
Lindsey N Young ◽  
Do Jin Kim ◽  
...  
Keyword(s):  
Complex I ◽  
Kinase Activity ◽  
Kinase Domain ◽  
Scaffolding Protein ◽  
Hydrogen Deuterium Exchange ◽  
Class Iii ◽  
Phosphatidylinositol 3 Kinase ◽  
Lipid Kinase ◽  
Hydrogen Deuterium ◽  
Phosphatidylinositol 3

The class III phosphatidylinositol 3-kinase complex I (PI3KC3-C1) that functions in early autophagy consists of the lipid kinase VPS34, the scaffolding protein VPS15, the tumor suppressor BECN1, and the autophagy-specific subunit ATG14. The structure of the ATG14-containing PI3KC3-C1 was determined by single-particle EM, revealing a V-shaped architecture. All of the ordered domains of VPS34, VPS15, and BECN1 were mapped by MBP tagging. The dynamics of the complex were defined using hydrogen–deuterium exchange, revealing a novel 20-residue ordered region C-terminal to the VPS34 C2 domain. VPS15 organizes the complex and serves as a bridge between VPS34 and the ATG14:BECN1 subcomplex. Dynamic transitions occur in which the lipid kinase domain is ejected from the complex and VPS15 pivots at the base of the V. The N-terminus of BECN1, the target for signaling inputs, resides near the pivot point. These observations provide a framework for understanding the allosteric regulation of lipid kinase activity.

scholarly journals Erythropoietin induces tyrosine phosphorylation and kinase activity of the c-fps/fes proto-oncogene product in human erythropoietin-responsive cells

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3193-3196 ◽  
Author(s):  
Y Hanazono ◽  
S Chiba ◽  
K Sasaki ◽  
H Mano ◽  
Y Yazaki ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Kinase Activity ◽  
Protein S ◽  
Receptor Activation ◽  
Kinase Domain ◽  
Cellular Protein ◽  
Erythroid Progenitor ◽  
Nonreceptor Tyrosine Kinase ◽  
Human Erythropoietin

Erythropoietin (EPO) is a hematopoietic growth factor that stimulates the proliferation and differentiation of erythroid progenitor cells. Although the EPO receptor has no kinase domain, EPO rapidly induces tyrosine phosphorylation of several proteins in EPO-responsive cells. Therefore, the receptor activation by the ligand could induce tyrosine- kinase activity of unidentified cellular protein(s). Here we show that c-fps/fes proto-oncogene product (p92c-fes), nonreceptor tyrosine kinase, is tyrosine-phosphorylated on treatment with EPO in a human erythroleukemia cell line TF-1 that is responsive to granulocyte- macrophage colony-stimulating factor, interleukin-3, and EPO. In addition, the kinase activity of p92c-fes was shown to be enhanced by treatment with EPO. Therefore, p92c-fes could be implicated in a signaling pathway triggered by EPO in human EPO-responsive cells.

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