Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 1. DAP5 Knockdown by shRNA Affects Cell Viability and Leads to Apoptotic Cell Death (A) (Left) Western blot of HeLa cells transiently transfected for 5 days with shRNA against DAP5 or HcRed (control). Antibodies against DAP5 and actin (loading control) were used. (Right) Graph represents densitometry analysis of the DAP5 bands after normalization to the actin bands; the control HcRed signal was set as 100%; the values represent the mean ± SD of ten experi- ments. (B) Light micrographs of HeLa cells treated as in (A). (C) HeLa cells transiently transfected for 5 days with indicated shRNA were treated with DMSO or zVAD for 24 hr. (Top) Graph indicates percentages of cell death as trypan blue-positive (dead) cells out of total cell number (normal- ized to 100%). (Bottom) Graph represents the absolute numbers of viable (trypan blue-excluding cells) per 10 mm2 field in hemicytometer. The values are presented as mean ± SD and calculated from triplicates. Asterisks mark statistically significant results (p < 0.01). The experiment was repeated several times with reproducible results. (D) Western blot of HeLa cells treated as in (C), using the indicated antibodies.

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: Knockdown, shRNA, Western Blot, Transfection, Control

Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 2. DAP5 Knockdown Triggers M Phase-Specific Apoptotic Cell Death (A) HeLa cells transiently transfected with shRNA against DAP5 or HcRed for 5 days were plated at similar cell densities, synchronized with taxol or thymidine for 16 hr, and then visualized by light microscopy. (B) Cells treated with taxol for 16 hr were assessed for cell death by measuring trypan blue uptake. Graph represents the mean ± SD of triplicates. Asterisks mark statistically significant result (p < 0.01). The experiment was repeated several times with reproducible results. (C) Cells were treated as in (A) with taxol, thymi- dine, or DMSO and then stained for DNA content with propidium iodide. Histograms represent distribution of 105 cells (y axes) according to their DNA content (x axes). (D) Cells were treated as in (A) with taxol in the absence or presence of zVAD and visualized by light microscopy. (E) Cells were treated as in (A) with taxol and zVAD. Cell death was measured by trypan blue exclusion (graph) or by FACS analysis for sub-G1 DNA content (histograms). The values are presented as mean ± SD and calculated from triplicates. (F) Steady-state levels of DAP5 protein and assessment of PARP-1 cleavage, under the indi- cated assay conditions.

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: Knockdown, Transfection, shRNA, Light Microscopy, Staining

Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 3. Bcl-2 Is a Putative DAP5 Translation Target (A) HeLa cells were transfected with shRNA to DAP5 or HcRed for 5 days. Steady-state levels of DAP5, Bcl-2, and actin were assessed by immunoblotting. Graph repre- sents densitometry analysis of the Bcl-2 bands after normalization to the actin bands; the HcRed signal was set as 100%; the values represent the mean ± SD of six experiments. (B) Western blot of cells treated as in (A), using the indi- cated antibodies. (C) Cells depleted of DAP5 as in (A) were treated with DMSO or zVAD for 24 hr. Steady-state levels of DAP5, Bcl-2, and actin were assessed by immunoblotting. (D) Total RNA was isolated from HeLa cells treated as in (A) and subjected to reverse transcription. Real-time PCR was performed on the cDNA samples. Relative amounts of Bcl-2 mRNA in each sample normalized to HPRT mRNA are presented as the mean ± SD of triplicates. The experiment was repeated three times with reproduc- ible results. (E) Cells depleted of DAP5 as in (A) were treated for 16 hr with 10 mM MG132 (right) or for 6 hr with 100 mM MG132 (left). Steady-state levels of the indicated proteins were measured by immunoblotting. (F) HeLa cells were cotransfected with DAP5 shRNA and pCDNA3 plasmid or Bcl-2 plasmid for 5 days. Cells were then treated with DMSO or taxol for 16 hr. (Top) Represen- tative western blot of DAP5 decrease in this experiment. (Bottom) Western blot of PARP-1, actin, and Bcl-2. The rescue experiment was repeated several times with reproducible results.

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: Transfection, shRNA, Western Blot, Isolation, Reverse Transcription, Real-time Polymerase Chain Reaction, Plasmid Preparation

Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 4. DAP5 Regulates Bcl-2 Translation (A and B) HeLa cells transfected with shRNA to DAP5 or HcRed for 5 days were analyzed for polysomal profile. (A) (Top) Polysomal profile of HcRed shRNA-trans- fected cells. The 40S, 60S, 80S, and polysomes are indicated. (Bottom) Upper graph represents distribution of actin mRNA. Lower graph represents distribution of Bcl-2 mRNA. (B) (Top) Polysomal profile of DAP5 shRNA-transfected cells. The 40S, 60S, 80S, and polysomes are indicated. Upper graph represents distri- bution of actin mRNA. Lower graph represents distribution of Bcl-2 mRNA. Graphs represent the mean ± SD of triplicated real-time PCR measurements of pooled fractions 6–12 indicated as subpolysomes and of each of fractions 13–23. Percent values indicate the abundance of mRNA in fractions 6–18 or 19–23 from the total amount of mRNA in fractions 6–23. (C and D) In vitro-transcribed mRNAs from the pRLBcl2FL or phpRLBcl2FL plasmids were introduced by transfection into HeLa cells 5 days after transfection with shRNA against DAP5 or HcRed. Luciferase activity was analyzed 6 hr following the RNA transfection. (C) (Top) Schematic representation of pRLBcl2FL mRNA transcript. RL, renilla luciferase; FL, firefly luciferase. (Bottom) Upper graph represents the ratio of firefly luciferase activity to renilla luciferase activity (relative activity). The average ratio activity in the HcRed-transfected cells has been designated as 1. Lower graphs represent the absolute values reflecting renilla and firefly luciferase activity, separately, for each transcript. (D) (Top) Schematic representation of phpRLBcl2FL mRNA transcript. (Bottom) Graph representing the absolute values of renilla and firefly luciferase activity, separately. The values represent the mean ± SD of triplicates. The experiment was repeated three times with reproducible results. Asterisks mark statistically significant results (p < 0.01).

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: Transfection, shRNA, Real-time Polymerase Chain Reaction, In Vitro, Luciferase, Activity Assay

Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 5. CDK1 mRNA Is a Putative DAP5 Target (A) Total RNA was isolated from immunoprecipitates of ectopically expressed Flag-DAP5/p86 by anti-Flag antibodies and was converted to cDNA. As negative controls, immunoprecipitates of nontransfected cells were used. Detection of DAP5 mRNA in the indicated mRNP complexes was done by PCR. (B) (Left) Schematic representation of the experimental strategy applied in the array experiments. (Right) Each pie represents results obtained from a single array experiment, in which the array hybridized to DAP5-associated cDNAs was compared to the array hybridized with template from the nontransfected control cells. Slices of the pie indicate the distribution of the genes represented on the array into three categories: those whose signal was elevated more than 2-fold compared to control (green), those with a more than 2-fold decrease in signal (red), and those exhibiting the same intensity of signal as the control (yellow). (C) Target validation. Total RNA was isolated from the immunoprecipitates of ectopically expressed Flag-DAP5/p86 (upper panel), and ectopically expressed Flag-DAP5/p97 (middle panel) using anti-Flag antibodies. To assess possible nonspecific binding, the anti-Flag antibodies were similarly applied in nontrans- fected cells (right slots). In addition, RNP complexes formed by the endogenous DAP5 were generated by anti-DAP5 antibodies in nontransfected cells (lower panel). For assessing possible nonspecific binding, the same procedure was repeated with a nonrelevant antibody (i.e., anti-Grb2, right slot). The RNAs were converted to cDNAs, and detection of CDK1 mRNA was done by PCR. Specific primers for SOD mRNA that fails to bind to DAP5 protein were used as a negative control.

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: Isolation, Control, Biomarker Discovery, Binding Assay, Generated, Negative Control

Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 6. Depletion of DAP5 by shRNA Affects Translation of CDK1 during Mitosis (A) HeLa cells were transiently transfected with shRNA against DAP5 or HcRed for 5 days and then synchronized by double thymidine block. Cells were collected 8 hr following the release from the second block. Western blot was performed with the indicated antibodies. Asterisk represents nonspecific band. Graph represents quantification of the signal by densitometry analysis; the HcRed signal was set as 100%. (B) HeLa cells were depleted of DAP5 as in (A) and treated with taxol in the presence or absence of zVAD for 16 hr, and then metabolically labeled with 35S-Met. Cell extracts were prepared, and equal amounts of radioactivity (5 3 107 CPM) were subjected to immunoprecipitation with anti-CDK1 antibodies. The immu- noprecipitates were separated on SDS-PAGE, and signal intensities were quantified by densitometry using the BAS-2000 PhosphorImager (Fuji) and ProbeQuant software (Fuji) (graph). Western blot was used to determine efficient knockdown of DAP5, and the percent of cells with 4n DNA content was determined by FACS analysis (top). (C) Total RNA was isolated from taxol-treated HeLa cells depleted of DAP5 and was converted to cDNA. The cDNA was subjected to real-time PCR. Relative amounts of CDK1 mRNA in each sample normalized to HPRT mRNA are presented as the mean ± SD of triplicates. The experiment was repeated three times with reproducible results. (D) HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 plasmid or CDK1 plasmid, as detailed in the Experimental Pro- cedures. Cells were then treated with taxol for 16 hr. (Top) Representative western blot of DAP5 decrease in this experiment. (Bottom) Western blot of PARP-1, actin, and CDK1. The rescue experiment was repeated several times with reproducible results. (E) HeLa cells were transfected with in vitro-transcribed mRNA corresponding to pRLCDK1FL or pRLFL. Luciferase activity was analyzed 6 hr following the trans- fection. (Top) Schematic representation of pRLCDK1FL and pRLFL mRNA transcripts. The pRLFL vector contains a linker of 100 bp instead of the IRES element. (Bottom) Upper graph represents relative luciferase activity (ratio of firefly/renilla). The average activity in the control vector has been designated as 1. Lower graphs represent the absolute values reflecting renilla and firefly luciferase activity, separately, for each transcript. The values represent the mean ± SD of triplicates. The experiment was repeated three times with reproducible results. Asterisks mark a statistically significant result (p < 0.01).

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: shRNA, Transfection, Blocking Assay, Western Blot, Metabolic Labelling, Labeling, Radioactivity, Immunoprecipitation, SDS Page, Software, Knockdown, Isolation, Real-time Polymerase Chain Reaction, Plasmid Preparation, In Vitro, Luciferase, Activity Assay, Control

Journal: Molecular cell

Article Title: DAP5 promotes cap-independent translation of Bcl-2 and CDK1 to facilitate cell survival during mitosis.

doi: 10.1016/j.molcel.2008.03.018

Figure Lengend Snippet: Figure 7. DAP5 Knockdown Cells Display a Decline in CDK1-Mediated Substrate Phosphorylation during Mitosis (A) FACS analysis of DAP5-depleted cells versus control cells stained with MPM-2 antibodies. Cells transfected with shRNA against DAP5 or HcRed for 5 days were treated with taxol for 16 hr and stained with MPM-2 antibodies. The same samples were further stained for DNA content with propidium iodide and analyzed by flow cytometry. MPM-2 and PI staining were detected as FITC and PE fluorescence, respectively. (Left) Histograms represent cell-cycle distribution of 105

Article Snippet: CDK1 rescue experiments were as follows: HeLa cells were transfected with DAP5 shRNA for 48 hr and then transfected with pCDNA3 (Invitrogen) or CDK1 (15 mg per 9 cm plate) (NM_001786.2, ORIGENE).

Techniques: Knockdown, Phospho-proteomics, Control, Staining, Transfection, shRNA, Cytometry