IndraLab
Statements
sparser
"Licensing is modulated by G 1 phase Cdks through phosphorylation and inactivation of NPM, as expression of NPM/B23 mutants whose phosphorylation sites were either deleted (NPM∆186-239) or replaced with a non-phosphorylatable residue (NPM T199A) resulted in suppression of centrosome duplication."
sparser
"Consistent with the IPA analysis of transcriptional response, exposure to 100 M H 2 O 2 uniquely induced hypophosphorylation of protein kinase C related kinase (Prk1) at T778 associated with cell migration and tumor metastasis and hyperphosphorylation of Npm1 at S4 associated with cell survival and growth, xref ."
sparser
"Indeed, it has been demonstrated that in the nucleus GRK5 interacts with and phosphorylates nucleophosmin (NPM1)[ xref ], a multifunctional protein involved in the regulation of cell cycle, centrosomal duplication and apoptosis, that is overexpressed in several cancer types [ xref ]."
sparser
"The post-translational modification of NPM1 regulates its DNA repair functions, where phosphorylated NPM1 has been shown to translocate to DNA double-strand breaks with γ-H2AX foci [ xref ], and the inhibition of this colocalization sensitizes cells to ionizing radiation [ xref ]."
sparser
"Cells expressing a mutant NPM that lacks seven potential Pin1 binding sites (GFP-NPM ΔPin1 ) had prolonged interphase and centrosome amplification (data not shown) compared to those that express wild-type NPM, indicating that cell-cycle dependent phosphorylation of NPM is highly correlated with cell cycle progression and Pin1 plays a critical role in this post-phosphorylation regulation."
sparser
"In KSHV-infected cells, NPM1 is a phosphorylation substrate for CDK6/K cyclin necessary for centrosome duplication, and p53-driven apoptosis occurring downstream of NPM1 phosphorylation is a critical checkpoint mechanism that prevents accumulation of cells with supernumerary centrosomes, which may be overcome by LANA co-expression xref ."
sparser
"To further investigate whether NPM phosphorylation regulates cell motility and cancer invasion through modulation of actin stress fiber, we examined stress fiber formation and polymerized actin in EV, Flag-tagged NPM and its phosphorylation site mutant (Thr234/237A) of Hep3B cells."
sparser
"In line with our conclusion that p110α H1047R expression leads to centrosome overduplication in S-phase, the activation of ROCK (as measured by the phosphorylation of MLC on Ser19) and the phosphorylation of Npm on T199 (a phosphorylation site of CDK2) xref were enhanced in p110α mutant cells (Fig. xref )."
trips
"We have identified NPM1 as a substrate for CDK6 activated by the Kaposi's sarcoma herpesvirus (KSHV) D-type cyclin and shown that p53-driven apoptosis occurs downstream of NPM1 phosphorylation as a checkpoint mechanism that prevents accumulation of cells with supernumerary centrosomes."
sparser
"To determine whether IKKα phosphorylates NPM, we used different NPM deletion and mutation forms as kinase substrates and found that IKKα phosphorylated the amino acid (aa) 119–195 region, which contains five serine sites, but a kinase-dead IKKα mutant (IKKα-KA) did not phosphorylate NPM ( xref ; xref )."
sparser
"This study provides a novel functional link between LANA and v-cyclin by showing that phosphorylation of nucleophosmin (NPM) by the v-cyclin-CDK6 kinase complex supports its interaction with LANA, and thus enables the transcriptional silencing of KSHV lytic genes needed for latency."
sparser
"In accordance with our finding that phosphorylation of NPM is needed for the interaction between LANA and NPM ( xref ), the LANA-NPM interaction was diminished in JSC-1 PEL cells, which had a very low level of NPM phosphorylation, as compared to BC-3 cells with highly phosphorylated NPM and prominent LANA-NPM co-precipitation ( xref )."
sparser
"GRK5 was identified to phosphorylate nucleophosmin (NPM1), therefore regulating sensitivity to polo-like kinase inhibitor-induced apoptosis of breast cancer cells xref , and its upregulation mediated by tazarotene-induced gene 1 (TIG1) significantly suppresses colon cancer growth xref ."
sparser
"While 24 h treatments led to decreased NPM1 phosphorylation, there were no changes in NPM1 phosphorylation at 3 h treatment ( xref , D and E ), We also analyzed the effect of lower concentration of OA, inhibitory for PP2A, on NPM1 phosphorylation using NPM1-GFP expressed in HEK293T cells."
sparser
"Importantly, we detected significantly stronger nuclear and, in particular, cytoplasmic staining of phospho-NPM1 (Thr199) in tumor tissue specimens from BRAFV600E-mutated in comparison with KRAS mutant/BRAF wild-type and double wild-type KRAS/BRAF colonic adenocarcinomas using immunohistochemistry."
sparser
"To better understand the nature of the in-cell PKA-treated phosphorylated NPM1 protein, mass-spectrometric analysis detected phosphorylation of at least five sites within the OD (namely, Thr75, Thr78, Ser82, Thr86 and Ser88, xref ), however, the corresponding phospho-motifs have negative scores with respect to 14-3-3 binding as predicted by 14-3-3-Pred [ xref ]."
sparser
"Crizotinib, identified in 2005, was originally synthesized as an MET inhibitor xref and subsequently found to inhibit phosphorylation of NPM‐ALK in both Karpas 299 and SU‐DHL‐1 anaplastic large‐cell lymphoma (ALCL) cells. xref The EML4 ‐ ALK translocation in NSCLC was discovered in 2007."
sparser
"Additionally, we found that adaphostin treatment induced a decrease in the phosphorylation of nucleophosmin, a major nuclear phosphoprotein, and that this decreased phosphorylation was a result of the p21- and p27-mediated inactivation of cyclin E-cyclin-dependent kinase 2 complex kinase activity."
sparser
"We examined the effect of (a) CTD-kinase, which contains the cdc2 catalytic component (p34) in a complex with a p58 subunit (cdc2/p58) and (b) the M phase-specific histone H1 kinase, which contains the cdc2 kinase in association with a p62 subunit (cdc2/p62), on phosphorylation of numatrin."
sparser
"Other than the hyperphosphorylation and inactivation of NPM and the nuclear accumulation of centrin intermediates, processes that are dependent on Cdk2, the centrosomal targets controlled by oncogenes and altered tumor suppressors directly responsible for centrosome amplification are largely unknown."
sparser
"The enzyme had an obvious K m of 4.36±0.5 mM , V max of 227.27±1.59 μmol min -1 mg -1 and k cat / K m of 441.35±0.04 mM -1 s -1 using p NPM as substrate, while K m of 58.34±1.75 mg ml -1 , V max of 285.71±10.86 μmol min -1 mg -1 and k cat / K m of 41.47±1.58 s -1 mg -1 mL for 1,4-β-D-mannan."
sparser
"The V max value of Tth Man5 β-mannosidase for p NPM is 227.27±1.59 μmol min -1 mg -1 , 7-fold higher than thermostable β-mannosidases from T. neapolitana and P. furiosus , 38-fold higher than T. fusca β-mannosidase and 62-fold than Thermoascus aurantiacus β-mannosidase [ xref , xref , xref , xref ]."
sparser
"The k cat / K m of Tth Man5 β-mannosidase for p NPM is 441.35±0.04 mM -1 s -1 , approximately 2-fold higher than A. niger β-mannosidase, 11-fold higher than the P. furiosus β-mannosidase, 18-fold higher than the T. neapolitana β-mannosidase and 80-fold higher than the Thermoascus aurantiacus β-mannosidase [ xref , xref , xref , xref ]."
sparser
"ALKIma1 cells grew for more than 100 days, presented with increased phosphorylation of NPM-ALK (Fig. xref A), typical ALCL morphology with large cells and a large nucleus (Fig. xref B) and showed robust telomerase activity, in agreement with the immortalized phenotype (Supplementary Fig. S xref D)."
sparser
"While CIGB-300 binds to and impairs the phosphorylation of nucleophosmin 1 (B23/NPM1), previously described as the molecular target of CIGB-300 in solid tumor cells [ xref ], the anti-leukemic effects of CIGB-300 in malignant T cells appear to be explained by direct CK2 enzyme inhibition."
sparser
"At late G 1 phase, NPM is phosphorylated by cyclin E-Cdk2, phosphorylation which induces NPM release from the centrosomes and the initiation of centrosomal duplication. xref We found that AKAP350CTD expression induced an increase in Cdk2 specific phosphorylation of NPM, indicating that AKAP350 enables Cdk2 centrosomal activity at the G 1 /S transition."
sparser
"Phosphorylation of NPM at several sites has been previously reported by several different kinases including casein kinase II (CKII), nuclear kinase II, polo-like kinase (Plk) and cdc type kinases (CDK1/cyclin B, CDK2/cyclin E, and CDK2/cyclin A) during mitotic regulation and centrosome duplication [ xref , xref ]."
sparser
"Cyclin E/Cdk2 phosphorylates p27 Kip1 to accelerate its proteasomal degradation, which is essential for mammalian cells to enter the S phase of the cell cycle. xref – xref Its expression is associated with not only accelerated cell proliferation but also histone mRNA synthesis/chromatin remodeling through phosphorylation of NPAT/p200 and centrosome amplification through phosphorylation of nucleophosmin and CP110."
sparser
"It has been found that protein expression levels of nucleophosmin are increased in 2D gel, whereas the Westernblot experiment using the anti-NPM antibody indicated that the total protein content of NPM did not change after Sal B treatment, since the differential protein spots showed electrophoretic mobility variation and moved to a more acidic position on the gel, which may be resulted from Sal B-mediated modification through post-translational phosphorylation of NPM."
sparser
"Human vascular endothelial cells treated with oxidized low density lipoprotein show dephosphorylated levels of NPM correlating with decreased proliferation and increased cellular dysfunction [ xref ], consistent with studies demonstrating enhanced endothelial cell proliferation correlating to increased NPM phosphorylation upon treatment with cardioprotective drugs [ xref ]."
sparser
"In addition, inhibition of NPM-ALK phosphorylation and function, lead to inhibition in key NPM-ALK signaling mediators including phospholipase C-γ, signal transducers and activators of transcription 3, extracellular signal regulated kinases, and Akt (a serine/threonine protein kinase that plays a key role in multiple cellular processes such as glucose metabolism, cell proliferation, apoptosis, transcription and cell migration).[ xref ]"
sparser
"To possibly intersect these results of changes in nuclear morphology and transcription rate with those of NPM phosphorylation and translocation, we looked for differences in monomer and oligomeric NPM levels in both cells, with and without UV stress, through semi-native gradient gels ( xref )."
sparser
"Interestingly, CIGB-300 was shown to bind NPM1 and to inhibit CK2-mediated phosphorylation of NPM1 at Ser125 inducing damage to the nucleolar architecture and massive apoptosis [ xref ], in line with the putative implication of NPM1 phospho-Ser125 in the maintenance of the nucleolar assembly, in ribosome biogenesis, and in cytokinesis [ xref , xref , xref ]."
sparser
"To elucidate the mechanism of how phosphorylation affects partitioning of NPM1 into the nucleolus, we investigated the impact of NPM1 phosphorylation on its self-association (homotypic) and heterotypic interactions with rRNA and ribosomal proteins (r-proteins), which are known to impact its condensation xref , xref (Fig. xref )."
sparser
"Despite being considered a phosphoprotein with phosphorylations on threonine 199, 234, and 237 that allow functions in centriole duplication ( xref ), and in the expression of DNA repair genes ( xref ; xref ; xref ), the identification of tyrosine phosphorylation on NPM and its biochemical functions have not yet been explored."
sparser
"We next studied the impact of UCM-13369 in the
genes and/or expression levels of NPM1 and NPM1 C+ pathway components
( xref A), including
the positive regulation of c-Myc xref and
the negative regulation of FBXW7 and the pro-apoptotic CASP8. xref Upon treatment with the compound in OCI-AML3
cell line, qPCR and Western blot revealed reduced levels for NPM1
and c-Myc, while FBXW7 was found to be upregulated (NPM1 p -value ≤0.0001, xref B,C)."
sparser
"The centrosome duplication cycle begins at the G1-S phase when the pair of centrioles dissociates. xref , xref Centrosome
disengagement in late G1 is licensed by the phosphorylation of nucleophosmin (NPM) via cyclin E/CDK2 complexes. xref , xref Prior work revealed that centriole disengagement occurs during anaphase when CDK2 is needed for centriole duplication in the next cell cycle. xref CDK2 is dispensable for normal centrosome duplication, but required for oncogene-induced centrosome overduplication. xref Mechanistic studies conducted in CDK4 −/− mouse embryonic fibroblasts (MEFs) established that centrosomes fail to separate at G1/S phase, while centrosomes achieve premature separation in CDK2 −/− MEFs. xref Activation of E2F transcription factors and functional CDK2-cyclin A complex are collectively required for centriole duplication. xref Inactivation of E2F3 can prevent premature centriole duplication, regulate centrosome amplification, and maintain chromosome stability by controlling cyclin E levels and cyclin E-dependent kinase activity. xref "
sparser
"SCID-Beige mice xenografted subcutaneously with NPM-ALK positive cells treated with crizotinib at 100mg/kg/day showed complete tumor regression within fifteen days, a significant tumor apoptosis induction, and a concomitant reduction in NPM-ALK phosphorylation and downstream signaling events [ xref - xref ]."
sparser
"As phosphorylation of human NPM by cyclin E–cdk2 was reported to be essential for the initiation of centrosome duplication in late G 1 ( xref ), we considered that ARF might inhibit NPM phosphorylation in addition to retaining it in the nucleolus to arrest cell growth before S-phase entry ( xref )."
sparser
"Re-probing of this membrane with a monoclonal antibody recognizing NPM showed that a 38 kDa protein band was present in all three lanes, indicating that the polyclonal antibody reacts specifically with NPM phospho-Thr 198 proteins, but does not cross-react with non-phosphorylated NPM."
sparser
"This is consistent with the hypothesis that in G1/S/G2 phases when the nuclear envelope is still intact and NPM is phosphorylated to permit centrosome duplication, many more molecules of NPM need to be phosphorylated in NPMc expressing cells due to the increased load of NPM in the cytoplasm."
sparser
"Aberrant NF-κβ expression was observed in various malignant tumors, including gastric cancer, xref breast cancer, xref and prostate cancer. xref NF-κβ activation initiates the transcription of MMP-2 and MMP-9, the increased MMPs proteins enhance the invasiveness of tumor cells through the degradation of extracellular matrix (ECM). xref , xref Besides, NF-κβ silencing promotes apoptosis in hematopoietic tumors via inhibiting Bcl-xL and XIAP. xref Recent studies revealed that NPM1 silencing inhibits prostate cancer cell growth, migration and invasion via reducing the phosphorylation of ERK1/2. xref We therefore hypothesized that Aurora-B-mediated NPM1 phosphorylation affects the OS phenotype via activating ERK/NF-κβ signaling."
sparser
"In combination with the earlier result showing that NPM-Thr 198 is constitutively phosphorylated, these data indicate that this particular NPM phosphorylation site is not subject to either positive (that is, cdk-mediated) or negative (that is, ARF-directed) regulation throughout the cell cycle, but is instead constantly being phosphorylated as total levels of NPM rise in the cell."
sparser
"To confirm that NPM is phosphorylated by v-cyclin on Thr199 in our experiments, U2OS cells were transfected with expression vectors for Myc-tagged v-cyclin or a vector control together with eGFP-tagged wild-type NPM (eGFP-NPM), or its phosphorylation site mutant T4A, with threonine to alanine mutations of NPM codons of 199, 214, 234, 237, and mutant T3A in which all but threonine 199 is replaced by alanine xref ."
sparser
"To verify the effect of the presence or absence of IKKα kinase on S125-NPM phosphorylation associated with centrosomes in cells, we performed IF staining and found that the anti-p-S125-NPM antibody stained centrosomes in cells containing one centrosome (G1 phase) and in dividing cells (M phase; xref ), but did not stain centrosomes well in cells containing two centrosomes (S or G2 phase; xref )."
sparser
"GTx‐186 is of particular interest because in a previous report this compound decreased significantly NPM‐ALK tyrosine phosphorylation in Karpas 299 and SU‐DHL‐1 cells (Narayanan et al ., xref ), similar to the TrkAi‐induced downregulation of NPM‐ALK phosphorylation observed in the current study."
sparser
"Although it cannot be ruled out that TrkAi induces nonselective effects on NPM‐ALK, the significant decrease in NPM‐ALK phosphorylation after specific downregulation of TrkA by siRNA strongly suggests that NPM‐ALK and TrkA interact reciprocally to sustain their phosphorylation/activation status, and the decrease in pNPM‐ALK was secondary to the decrease in pTrkA."
sparser
"In addition, inhibition of key NPM-ALK signaling mediators, including phospholipase C-gamma, signal transducers and activators of transcription 3, extracellular signal-regulated kinases, and Akt by PF-2341066 were observed at concentrations or dose levels, which correlated with inhibition of NPM-ALK phosphorylation and function."
sparser
"We have identified NPM1 as a substrate for CDK6 activated by the Kaposi's sarcoma herpesvirus (KSHV) D-type cyclin and shown that p53-driven apoptosis occurs downstream of NPM1 phosphorylation as a checkpoint mechanism that prevents accumulation of cells with supernumerary centrosomes."
sparser
"Furthermore, it is possible that acetylation primarily modulates NPM-HDAC1 and NPM-LANA interactions in the ternary complex of NPM-HDAC1-LANA, but does not interfere with the HDAC1-LANA interaction after the recruitment of HDAC1 to the complex has occurred by phosphorylated NPM."
sparser
"The data demonstrating a significant reduction in the phosphorylation of NPM upon silencing of CDK6 expression in KSHV-infected endothelial and lymphoid cells ( xref ) may open up novel opportunities for developing targeted therapies for intervention and treatment of KSHV associated malignancies."
sparser
"To confirm that PP1 was involved in NPM1 phosphorylation, we analyzed endogenous NPM1 phosphorylation in CEM T cells treated with 10 μM 1E7-03 (24 h) or 100 nM OA (2 h), which served as positive control as OA inhibits PP1 at higher 10 nM concentrations and PP2A at lower 3 nM concentration ( xref )."
sparser
"Activated STAT1 is well-established as an antagonist of oncogenic STAT3, driving tumor-suppressive pro-apoptotic gene expression opposing the STAT3 survival program to which ALK-positive ALCL is addicted. xref , xref , xref Interestingly, however, STAT1 activation at lower levels also helps promote ALK-positive ALCL oncogenesis, contributing to expression of the anti-apoptotic protein MCL1. xref Wu and colleagues previously showed STAT1 is a direct phospho-substrate of NPM1-ALK, tending to drive it toward proteasomal degradation in the cytoplasm. xref Interestingly, pSTAT3 is more favorably imported to the nucleus than pSTAT1 when both are present in the cytoplasm, xref which might explain the delicate balance between STAT1 activation and degradation necessary for survival in ALCL’s baseline state."
sparser
"Recently, another DNA damage response pathway—the ataxia telangiectasia mutated (ATM)-mediated pathway—has been identified as a novel signaling pathway that regulates ARF localization by modulating serine/threonine-protein kinase Nek 2 (Nek2)-dependent NPM phosphorylation [ xref ]."
sparser
"The opposing effects of mitotic phosphorylation of Ki-67 and NPM1 on their LLPS, together with their cell cycle-specific interaction (Extended Data Fig. xref ), underlie the morphological changes of nucleoli and the chromosome periphery during mitosis (Extended Data Fig. xref )."
sparser
"In contrast, mitotic hyperphosphorylation of nucleophosmin (NPM1), an IDR-rich nucleolar protein that interacts with Ki-67 and plays a critical role in assembling nucleolar components in interphase cells xref , diminishes the alternating charge blocks that otherwise exist in the non-phosphorylated form (Extended Data Fig. xref )."
sparser
"The exact role of this viral protein in regulating KSHV life cycle is not fully understood but studies indicate that v-Cyclin mediates phosphorylation of nucleophosmin (NPM), through its association with CDK6 and facilitates NPM-LANA interaction and recruitment of HDAC1 to promote KSHV latency [ xref ]."
sparser
"In addition, it has been reported that phosphorylation of NPM1 can inhibit its ability to bind with p14ARF, thereby preventing nucleolar sequestration of p14ARF; xref thus, we assessed whether SOX6 affects the phosphorylation status of NPM1 and the interaction of NPM1 and p14ARF."
sparser
"It has been reported that ATM-mediated phosphorylation of NPM1 can inhibit the binding of NPM1 with p14ARF, and thereby promoting the translocation of p14ARF to nucleoplasm. xref , xref Besides, AKT-mediated phosphorylation of NPM-Ser48 can prevent the oligomerization of NPM1, and subsequently results in nucleoplasmic localization of p14ARF, constitutive HDM2 inhibition and stabilization of p53. xref However, we observed no effect of SOX6 on the phosphorylation of NPM1."
sparser
"Since in vitro PKA-mediated phosphorylation of NPM1 was not feasible, we attempted a more effective strategy in which NPM1 phosphorylation was conducted in E.coli cells by co-expression with PKA, which has proven efficient for obtaining multiply phosphorylated proteins such as human Tau [ xref ] and SARS-CoV-2 nucleoprotein [ xref ]."
sparser
"Rho-associated kinases (ROCK2), PLK2 and PLK4 are essential for centrosome duplication in cells blocked by DNA synthesis inhibitors; In the centrosome amplification rescue assay, PLK2 indirectly activates ROCK2 by phosphorylation of NPM, while PLK4 acts downstream of ROCK2 to drive and block centrosome amplification in cells ( xref )."
sparser
"A complete picture of the NPM1 regulation by phosphorylation remains elusive in part due to the lack of knowledge on the effect of site-specific NPM1 phosphorylation, which reflects a more general challenge associated other multisite phosphorylated proteins, including human Tau [ xref , xref , xref ], CFTR [ xref ], LRRK2 [ xref ] and SARS-CoV-2 nucleoprotein [ xref , xref ], all of which represent established multi-site binders of 14-3-3 proteins."
sparser
"While these sites are located within the pentameric N-terminal domain of NPM1, like the Ser260 and Ser293 sites located within the helical C-terminal domain, all of them can be exposed upon NPM1 phosphorylation, which destabilizes their ordered structures due to the direct interference with the protein interfaces ( xref )."
sparser
"Considering that phosphorylated, dissociated NPM1 loses its ability to bind to the heparin column (a proxy of its binding to polyanionic nucleic acids) ( xref ), we propose that phosphorylation of nucleolar NPM1 releases NPM1-bound nucleic acids and leads to phospho-NPM1 monomerization, partial unfolding ( xref ) and 14-3-3 recruitment ( xref )."
sparser
"It is also tantalizing to suggest that 14-3-3/phospho-NPM1 interaction dissected in the present work may have significant implications in the liquid-liquid phase separation properties of NPM1, an activity relevant for maintaining stability and integrity of the membraneless organelle nucleolus [ xref ]."
sparser
"The kinetic parameters, K m and V max values of ReLipA toward p NPC, p NPL, and p NPM were determined to be 2.3 ± 0.21 mM and 1288 ± 48.5 μmol min −1 mg −1 , 0.64 ± 0.06 mM and 384.8 ± 17.5 μmol min −1 mg −1 , and 0.1 mM ± 0.01 and 185.8 ± 7.51 μmol min −1 mg −1 , respectively (Table xref )."
sparser
"As a serine/threonine protein kinase, CDK6 plays a crucial noncanonical role in diverse cellular processes, including inflammation xref and cellular differentiation xref , by phosphorylating NPM1 and NF-κB. In addition, CDK6 also acts as a transcriptional regulator in a kinase-independent manner by interacting with STAT3, Runx1, and c-Jun xref , xref , xref ."