Journal: Cell reports

Article Title: MYC Dysregulates Mitosis, Revealing Cancer Vulnerabilities

doi: 10.1016/j.celrep.2020.02.041

Figure Lengend Snippet: (A and B) Western blot of TPX2 and cleaved PARP (A) and micrographs (B) of RPE-NEO and RPE-MYC cells 3 days after transfection with control (ctrl) or TPX2 siRNA. Scale bar, 100 μm.

Article Snippet: The following antibodies were used as indicated: mouse anti-α-tubulin DM1 (1:1,000, T6199, Sigma), human anti-centromere (CREST, 1:50, 15–234 Antibodies Incorporated), rabbit anti-γ-tubulin (1:1,000, T3559, Sigma), rabbit anti-TPX2 (1:500, HPA005487, Sigma), mouse anti-centrin 20H5 (1:300, 04–1624, Millipore).

Techniques: Western Blot, Transfection

Journal: Cell reports

Article Title: MYC Dysregulates Mitosis, Revealing Cancer Vulnerabilities

doi: 10.1016/j.celrep.2020.02.041

Figure Lengend Snippet: (A) Time-lapse images of RPE-MYC cells expressing the FUCCI cell-cycle marker 12 h after transfection with control (sictrl) or TPX2 (siTPX2) siRNA. Fluorescence and phase-contrast images were overlaid. Scale bars, 20 μm.

Article Snippet: The following antibodies were used as indicated: mouse anti-α-tubulin DM1 (1:1,000, T6199, Sigma), human anti-centromere (CREST, 1:50, 15–234 Antibodies Incorporated), rabbit anti-γ-tubulin (1:1,000, T3559, Sigma), rabbit anti-TPX2 (1:500, HPA005487, Sigma), mouse anti-centrin 20H5 (1:300, 04–1624, Millipore).

Techniques: Expressing, Marker, Transfection, Fluorescence

Journal: Cell reports

Article Title: MYC Dysregulates Mitosis, Revealing Cancer Vulnerabilities

doi: 10.1016/j.celrep.2020.02.041

Figure Lengend Snippet: (A–H) RPE-MYC cells expressing doxycycline-inducible shRNA against TPX2 in the absence (−shTPX2) and presence (+shTPX2) of doxycycline for 4 days.

Article Snippet: The following antibodies were used as indicated: mouse anti-α-tubulin DM1 (1:1,000, T6199, Sigma), human anti-centromere (CREST, 1:50, 15–234 Antibodies Incorporated), rabbit anti-γ-tubulin (1:1,000, T3559, Sigma), rabbit anti-TPX2 (1:500, HPA005487, Sigma), mouse anti-centrin 20H5 (1:300, 04–1624, Millipore).

Techniques: Expressing, shRNA

Journal: Cell reports

Article Title: MYC Dysregulates Mitosis, Revealing Cancer Vulnerabilities

doi: 10.1016/j.celrep.2020.02.041

Figure Lengend Snippet: KEY RESOURCES TABLE

Article Snippet: The following antibodies were used as indicated: mouse anti-α-tubulin DM1 (1:1,000, T6199, Sigma), human anti-centromere (CREST, 1:50, 15–234 Antibodies Incorporated), rabbit anti-γ-tubulin (1:1,000, T3559, Sigma), rabbit anti-TPX2 (1:500, HPA005487, Sigma), mouse anti-centrin 20H5 (1:300, 04–1624, Millipore).

Techniques: Recombinant, Viability Assay, Staining, DNA Purification, RNA Sequencing Assay, Expressing, shRNA, Plasmid Preparation, Software

Journal: Clinical cancer research : an official journal of the American Association for Cancer Research

Article Title: Combined functional genome survey of therapeutic targets for hepatocellular carcinoma.

doi: 10.1158/1078-0432.CCR-09-2214

Figure Lengend Snippet: Fig. 5. Protein expression in HCC. Hematoxylin and eosin (HE) staining (original magnification, × 100) and immunoperoxidase staining (original magnifications, × 100 and × 400) of AKR1B10, HCAP-G, RRM2, and TPX2 proteins in HCC and adjacent nontumorous liver tissue. The specificity of antibodies was determined by immunoblotting of the KIM-1 cell lysate (left). N, nontumorous liver.

Article Snippet: Anti-TPX2 antibody was purchased from Novus Biologicals.

Techniques: Expressing, Staining, Immunoperoxidase Staining, Western Blot

Journal: Journal of Biological Chemistry

Article Title: TPX2 Inhibits Eg5 by Interactions with Both Motor and Microtubule

doi: 10.1074/jbc.m114.612903

Figure Lengend Snippet: FIGURE 1. Binding of TPX2 and TPX2-710 to microtubules. A, schematic diagram of the TPX2 constructs (left) and Coomassie Brilliant Blue-stained gel of the purified proteins (right). B, co-sedimentation of TPX2 with microtubules. S, supernatant; P, pellet. The concentration of microtubules in each pair of lanes is noted above. Western blots were stained for TPX2 or tubulin. C, quantification of apparent affinity was performed using a quadratic fit. The experiment was performed twice, and the values were averaged. Error bars, S.D.

Article Snippet: The proteins were then transferred to a PVDF membrane and probed using antibodies against TPX2 (Novus Biologicals, Littleton, CO) and tubulin (DM1A, SigmaAldrich).

Techniques: Binding Assay, Construct, Staining, Purification, Sedimentation, Concentration Assay, Western Blot

Journal: Journal of Biological Chemistry

Article Title: TPX2 Inhibits Eg5 by Interactions with Both Motor and Microtubule

doi: 10.1074/jbc.m114.612903

Figure Lengend Snippet: FIGURE 2. Binding Dynamics of TPX2 and TPX2-710. A, box plot showing release of TPX2 and TPX2–710 from microtubules in the presence of the indicated concentration of KCl added to the buffer. TPX2 fluorescence is reported as arbitrary units (A.U.). Whiskers define the range, boxes encompass the 25th to 75th quartiles, and lines depict the medians. B, TPX2 and TPX2-710 binding to untreated and subtilisin A-digested microtubules; top panels, fluorescence images of TPX2-Halo or TPX2–710-Halo bound to untreated and subtilisin A-digested microtubules; middle, quantification of TPX2 fluorescence; bottom, polyacrylamide gel showing digested and control microtubules. TPX2 fluorescence was measured for at least 60 microtubules for each of two independent experiments; error bars, S.D. C, kymograph of TPX2-Halo and TPX2-710-Halo on microtubules. Vertical scale bar (time), 60 s; horizontal scale bar, 2 m.

Article Snippet: The proteins were then transferred to a PVDF membrane and probed using antibodies against TPX2 (Novus Biologicals, Littleton, CO) and tubulin (DM1A, SigmaAldrich).

Techniques: Binding Assay, Concentration Assay, Fluorescence, Control

Journal: Journal of Biological Chemistry

Article Title: TPX2 Inhibits Eg5 by Interactions with Both Motor and Microtubule

doi: 10.1074/jbc.m114.612903

Figure Lengend Snippet: FIGURE 4. Inhibition of Eg5 by TPX2 requires both binding to the microtubule and an interaction between TPX2 and Eg5. A, kymographs of Eg5-EGFP before andfollowingtheadditionofTPX2orTPX2–710;arrowhead,timeoftheTPX2addition.B,quantificationofEg5-EGFPvelocity;errorbars,S.D.C,kymographofkinesin-1 EGFP dimers walking on microtubules before and after the addition of TPX2 (arrowhead). 1 nM kinesin-1 EGFP (green) and 500 nM TPX2-Halo (red) were used. D, kymographs of Eg5-EGFP (green) before and following the addition of 20 nM TPX2-Halo (red). Right panels, enlarged view. E, kymographs of Eg5-EGFP that was premixedwithTPX2-HaloorTPX2–710-Halo.F,quantificationofEg5-EGFPvelocityinthepresenceof50nMTPX2thatwasHalo-tagged(left)oruntagged(right).Error bars, S.E. Horizontal scale bars (A, C, and E), 1 m; horizontal scale bar (D), 2 m; vertical scale bar, 60 s (A, D, and E) and 5 s (C).

Article Snippet: The proteins were then transferred to a PVDF membrane and probed using antibodies against TPX2 (Novus Biologicals, Littleton, CO) and tubulin (DM1A, SigmaAldrich).

Techniques: Inhibition, Binding Assay

Journal: Oncology letters

Article Title: Reversal of the tamoxifen‑resistant breast cancer malignant phenotype by proliferation inhibition with bromosulfonamidine amino‑podophyllotoxin.

doi: 10.3892/ol.2024.14506

Figure Lengend Snippet: Figure 4. Effect of BSAPPT on apoptosis and cycle‑related gene or protein expression in MCF‑7, MCF7/TAMR and other cancer cells. (A) mRNA expres‑ sion levels of genes linked to the cell cycle and apoptosis were measured by qPCR both before and after MCF‑7 and MCF7/TAMR cells were treated with 10 µg/ml BSAPPT. (B) Western blotting detection of apoptotic and cycle‑related protein expression variations in MCF‑7 and MCF7/TAMR cells before and after using 10 µg/ml BSAPPT. Results of qPCR analysis that assessed differences in the level of expression of genes linked to the cell cycle and apoptosis before and after (C) A549 and (D) MDA‑MB‑231 cells were treated with 10 µg/ml BSAPPT. *P<0.05; **P<0.01; ***P<0.001. BSAPPT, bromosulfonamidine amino‑podophyllotoxin; qPCR, quantitative PCR; Bcl‑2, B‑cell lymphoma 2; Caspase, cysteine aspartic acid‑specific protease; PLK, polo like kinase; CCNB1, cyclin B1; TPX2, targeting protein for Xklp2; Bax, Bcl‑2 associated X; Cyt‑C, cytochrome c; Apaf‑1, apoptotic protease activating factor 1.

Article Snippet: Mouse anti‐human Caspase‐9 antibodies (cat. no. 9508S; 1:1,000) were purchased from Cell Signaling Technology, Inc., rabbit anti‐human Bcl‐2 (cat. no. BA0412; 1:1,000) and cyclin B1 (CCNB1; cat. no. BA0766; 1:1,000) antibodies were purchased from Wuhan Boster Biological Technology, Ltd., rabbit anti‐human polo like kinase (PLK)‐1 antibodies (cat. no. 10305‐1‐AP; 1:1,000) and targeting protein for Xklp2 (TPX2) antibodies (cat. no. 11741‐1‐AP; 1:2,000) were purchased from Proteintech Group, Inc., and the rabbit anti‐human PLK‐4 antibodies (cat. no. A9863; 1:1,000) were purchased from ABclonal Biotech Co., Ltd.

Techniques: Expressing, Western Blot, Real-time Polymerase Chain Reaction

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: The evolutionary conserved Thr72 in human TPX2 is phosphorylated by Cdk1 and Cdk2 in vitro. A, comparative alignment of part of human TPX2 sequence (amino acids 41 to 80) with corresponding sequences from other species (mouse, rat, and frog) using DNAMAN software (Lynnon Corporation). The sequence alignment shows that Thr72 in human TPX2 is conserved in all other species. B, schematic diagram of the experimental protocol for mass spectrometry analysis (LC-MS/MS) using mitotic HeLa cells. HeLa cells were synchronized at M phase by nocodazole treatment (100 ng/ml) for 16 h and released for 30 min after nocodazole washout. Endogenous TPX2 was immunoprecipitated from 10 mg of total protein using pan-TPX2 Abs (clone 184). IP sample was run on SDS-PAGE and after Coomassie Blue staining, the band with the matching size to TPX2 (confirmed by Western blotting with TPX2 Abs, not shown) was cut out and sent for LC-MS/MS analysis. The gray asterisk on the spectra of the phosphopeptide containing Thr72 indicate the identified matched fragment ions on mass spectrometry. C, phosphorylation sites identified by mass spectrometry analysis on endogenous TPX2 immunoprecipitated from nocodazole-synchronized mitotic HeLa cells in regards to the known TPX2 domains. All these sites have been identified previously (17, 19,–32) but not confirmed and analyzed. Thr72 is the first validated and functionally characterized phosphorylation site in human TPX2 (this study). D, in vitro kinase assay using purified Cdk1/2 proteins and phosphospecific Thr72 TPX2 Abs. Purified GST fusion protein TPX2 WT, GST-TPX2-T72A, or GST-TPX2-T72E was incubated with each active Cdk-cyclin complex in the presence of 1 mm cold ATP. All kinase reactions were stopped by adding 2× SDS sample buffer and the samples were run on SDS-polyacrylamide gel electrophoresis followed by Western blot detection using the indicated antibodies.

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: In Vitro, Sequencing, Software, Mass Spectrometry, Liquid Chromatography with Mass Spectroscopy, Immunoprecipitation, SDS Page, Staining, Western Blot, Kinase Assay, Purification, Incubation, Polyacrylamide Gel Electrophoresis

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: Thr(P)72 TPX2 antibodies are specific in Western blot for TPX2 phosphorylated at Thr72in vivo. A, specificity of Thr(P)72 TPX2 for TPX2 protein tested by siRNA. HeLa cells were transfected with control siRNA or one of two TPX2 siRNAs for 24 h and synchronized at M phase with nocodazole treatment (100 ng/ml). Cells were harvested and lysed with lysis buffer. Samples were run on SDS-PAGE, followed by Western blotting, first probed with the Thr(P)72 TPX2 Abs, then stripped and re-probed with pan-TPX2 (clone 184) Abs. Levels of actin were used as loading controls. B, bar graph quantitation for the relative expression levels of Thr(P)72 TPX2 and TPX2 in control and TPX2 siRNA-transfected cells. Each sample was compared with sample treated with control siRNA. Relative expression levels of Thr(P)72 for control siRNA, 1 ± 0; TPX2 siRNA #1 (UTR), 0.318 ± 0.085; TPX2 siRNA #2 (Cds), 0.289 ± 0.115. Relative expression levels of TPX2, control siRNA, 1 ± 0; TPX2 siRNA #1, 0.335 ± 0.0074; TPX2 siRNA #2, 0.304 ± 0.091 (mean ± S.E.). n = 4 samples, from 4 independent experiments. Unpaired Student's t test indicated all the results are significant. ***, p < 0.001. C, specificity of Thr(P)72 TPX2 tested by the use of T72A mutant and λ-PPase treatment. HeLa cells were left untransfected, transfected with an empty GFP vector, GFP-TPX2 WT, or GFP-TPX2 T72A mutant plasmids. 24 h after transfection, cells were synchronized with nocodazole for 16 h, harvested, and lysed. TPX2 immunoprecipitation was performed in each sample with TPX2 Abs (clone 183). Where indicated, IP beads were treated with λ-PPase before SDS-PAGE. The blot was first probed with the Thr(P)72 TPX2 Abs. After stripping, the same blot was re-probed with pan-TPX2 Abs (clone 184).

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: Western Blot, Transfection, Lysis, SDS Page, Quantitation Assay, Expressing, Mutagenesis, Plasmid Preparation, Immunoprecipitation, Stripping Membranes

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: In vivo TPX2 phosphorylation at Thr72 is cell cycle-dependent and peaks at M phase. A, cell cycle profiles analyzed by flow cytometry analysis to confirm cell synchronization at each phase. B, after IPs with pan-TPX2 Abs (clone 184), Western blots were probed first with the Thr(P)72 TPX2 Abs and then, after stripping, re-probed with pan-TPX2 Abs (clone 184). The levels of α-actin were used as loading controls. The levels of cyclin B1 were used as positive controls to show that synchronization at M phase worked well, as indicated by the high level of cyclin B1 in M phase compared with that of S phase or non-synchronized cells. The Western blot figures are representative of 3 independent experiments. The input blot is from the mitotic samples. C, bar graphs for quantification of relative levels of Thr72 phosphorylation are shown. Non-syn, non-synchronized cells (1 ± 0); M, M phase cells (4.16 ± 0.36); S, S phase cells (1.31 ± 0.4); mean of the relative levels of Thr(P)72 TPX2/TPX2 expression ± S.D., n = 3 independent experiments; ***, non-syn versus M phase, p < 0.001; **, M versus S phase, p < 0.01; NS, not significant: non-syn versus S phase, all by unpaired Student's t test.

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: In Vivo, Flow Cytometry, Western Blot, Stripping Membranes, Expressing

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: Phosphorylation of TPX2 at Thr72 is inhibited by the Cdk inhibitor roscovitine. A, the levels of Thr(P)72 were reduced by roscovitine treatment. HeLa cells were first treated with 100 ng/ml of nocodazole for 16 h and then once synchronized, treated with dimethyl sulfoxide (as a control), or 20 and 40 μm roscovitine for 30 min. Cells were harvested, lysed, and TPX2 was immunoprecipitated with pan-TPX2 Abs (clone 184). SDS-PAGE was performed and followed by Western blotting with Thr(P)72 and pan-TPX2 Abs (clone 184). B, cyclin B1 levels were also used to confirm that roscovitine-treated cells had remained in mitosis. The levels of p-Cdk/MAPK substrates (PX(S*/T*)P or (S*/T*)PX(R/K) motif) were also used to confirm the effectiveness of the treatment. Actin levels were used as loading control.

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: Immunoprecipitation, SDS Page, Western Blot

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: Localization of Thr(P)72 TPX2 in HeLa and 293 cells. Mitotic (A and B) and interphase (C) HeLa cells were stained with Abs directed against Thr(P)72 TPX2, TPX2, and tubulin or with the Thr(P)72 Abs pre-absorbed with blocking peptide at different ratios. A, in mitotic cells, TPX2 phosphorylated at Thr72 is localized in the cytosol and does not strictly associate with the mitotic spindle. B, HeLa cells stained with pan-TPX2 and Thr(P)72 TPX2 Abs preincubated with Thr(P)72 blocking peptides. C, during interphase, Thr(P)72 TPX2 is localized in the nucleus. Note that the expression levels of Thr(P)72 are much lower in interphase cells than in mitotic cells. Note that only the Thr(P)72 signal was blocked. D, representative photographs of mitotic 293 cells transfected with GFP-TPX2 WT (WT) and GFP-TPX2 T72A (T72A). Scatter plots show the GFP signal at microtubules relative to total GFP signal. GFP-TPX2 T72A is significantly enriched on microtubules when compared with GFP-TPX2 WT (GFP-TPX2 WT (0.26 ± 0.01, n = 29) versus GFP-TPX2 T72A (0.39 ± 0.02, n = 22), group (mean ± S.E.); ***, p < 0.0001 by t test). Scale bar, 10 μm.

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: Staining, Blocking Assay, Expressing, Transfection

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: Effects of GFP-TPX2 T72A on the polarity of mitotic spindles in HeLa cells with or without endogenous TPX2. A, representative photographs of mitotic HeLa cells at prometaphase and metaphase with monopolar, bipolar, and multipolar mitotic spindle poles. Scale bar, 10 μm. B, Western blots showing the levels of endogenous TPX2, GFP-TPX2 WT, and GFP-TPX2 T72A in cells with intact levels of TPX2. C, bar graphs showing the number of cells with different mono-, bi-, or multipolar mitotic spindles in each group. Cells with mitotic spindles were fixed and stained with Cy3-conjugated tubulin for MT visualization. GFP-TPX2 T72A expression results in a significant increase in the percentage of cells with multipolar spindles in the presence of endogenous TPX2. ANOVA comparing the three groups shows high significance with p < 0.001. Neuman-Keuls test was used to compare each group: GFP (1.49 ± 0.47) versus T72A (12.72 ± 2.10), p < 0.001; TPX2 WT (3.36 ± 0.40) versus T72A (12.72 ± 2.10), p < 0.001; group (mean ± S.E.); ***, p < 0.001; NS, not significant (GFP versus TPX2). At least 100 cells for each set of experiments were used for quantification, 5 independent experiments were performed. Error bars indicate S.E. D, Western blots showing the levels of endogenous TPX2, GFP-TPX2 WT, and GFP-TPX2 T72A in HeLa cells co-transfected with GFP-vector, GFP-TPX2 WT, or GFP-TPX2 T72A together with TPX2 siRNA targeting the 3′ UTR of TPX2 mRNA. E, bar graphs showing the number of cells with different mono-, bi-, or multipolar mitotic spindles in each group. Cells with mitotic spindles were fixed and stained with Cy3-conjugated tubulin for MT visualization. Knockdown of TPX2 in GFP-transfected cells results in a significant 5.4% increase in multipolar spindles versus control cells without TPX2 depletion. GFP-TPX2 T72A expression produces an even greater 9.8 and 7.5% increase in the percentage of cells with multipolar spindles when compared with GFP/TPX2 siRNA and GFP-TPX2 WT/TPX siRNA, respectively. n = 3, ANOVA test was used the compare the four groups (p < 0.01). The Neuman-Keuls test was used to compare the following groups: control (with control siRNA) (2.43 ± 0.41) versus GFP (7.94 ± 1.5), p < 0.05; GFP (7.94 ± 1.5) versus TPX2 WT (10.13 ± 1.2), NS; WT (10.13 ± 1.2) versus T72A (17.67 ± 3.2), p < 0.05; GFP (7.94 ± 1.5) versus T72A (17.67 ± 3.2), p < 0.05; group (mean ± S.E.); *, p < 0.05; NS, not significant. n = at least 500 cells for each set of experiments; 3 independent experiments were performed. Error bars indicate S.E.

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: Western Blot, Staining, Expressing, Transfection, Plasmid Preparation

Journal: The Journal of Biological Chemistry

Article Title: Phosphorylation of Targeting Protein for Xenopus Kinesin-like Protein 2 (TPX2) at Threonine 72 in Spindle Assembly *

doi: 10.1074/jbc.M114.591545

Figure Lengend Snippet: Overactivation of Aurora A and increased spindle length, a measure of Eg5 activity, in TPX2 T72A-expressing cells. A–C show 293 mitotic cells (prometaphase/metaphase) previously transfected with GFP-TPX2 WT (WT) or GFP-TPX2 T72A (T72A) expression vectors. A, representative photographs of WT- and T72A-transfected cells stained for Thr(P)288, a phosphoresidue indicative of the activity of Aurora kinase A. Dotted circles identify the poles. Scatter plots show the P-Aurora signal at centrosomes relative to total GFP signal. GFP-TPX2 T72A induces higher Aurora A activity than GFP-TPX2 WT (GFP-TPX2 WT (0.07 ± 0.01, n = 13) versus GFP-TPX2 T72A (0.14 ± 0.03, n = 18); *, p < 0.05 by t test). B, representative photographs of the spindle length detected in mitotic 293 cells transfected with GFP-TPX2 WT or T72A. Scatter plots show the spindle length in both groups. T72A-expressing cells display longer spindles than WT-expressing cells (GFP-TPX2 WT (58.95 ± 2.12, n = 18) versus GFP-TPX2 T72A (66.67 ± 2.20, n = 21); **, p < 0.01 by t test). C, representative images of the α-tubulin signal detected in GFP-TPX2 WT and T72A-trasnfected 293 cells. No significant difference was detected between these two groups (GFP-TPX2 WT (1.93 ± 0.41, n = 15) versus GFP-TPX2 T72A (1.97 ± 0.49, n = 13); NS, non significant by t test). In all the panels: the group is the mean ± S.E.. Scale bar, 10 μm.

Article Snippet: Endogenous TPX2 was immunoprecipitated from 10 mg of total protein lysates using TPX2 Abs (clone 184, Novus Biologicals) and Protein A/G-Sepharose 4 Fast Flow beads.

Techniques: Activity Assay, Expressing, Transfection, Staining