Journal: Molecular and Cellular Biology

Article Title: LDB1 Enforces Stability on Direct and Indirect Oncoprotein Partners in Leukemia

doi: 10.1128/MCB.00652-19

Figure Lengend Snippet: Halo-tagged proteins expressed from recombinant lentiviruses have physiological abundance and localization and can be precisely quantified in lysates or live cells. (A) Cell lysates were prepared from untransduced Jurkat cells; Jurkat cells transduced with Halo-LMO2; untransduced K562 cells; K562 cells transduced with Halo-LMO2; and KOPT-K1, LOUCY, and U937 cells. Lysates were subjected to 4% to 15% SDS-PAGE, transferred, and blotted with anti-LDB1, anti-LMO2 monoclonal antibody, anti-Halo, anti-TAL1, and anti-VCP (gel loading control). Molecular weight standards were run on the same gel and are shown at the right. (B) The top panel shows an immunoblot of lysates prepared from U2OS with a Halo knock-in at CTCF (lane 1) or lysates from Jurkat cells transduced with the constructs shown in the grid above (lanes 2 to 14). Empty vector control is shown as EBFPII-Hygro (lane 2). Lanes 2 to 9 show lysates from Jurkat cells lentivirally expressing Halo-CTCF at increasing MOIs. Lanes 10 to 14 show lysates from Jurkat cells lentivirally expressing Halo-SOX2 at increasing MOIs. The top panel shows gradient SDS-PAGE, transfer, and blotting with anti-CTCF antibody. The middle panel shows direct in-gel Halo fluorescence. Live cells prepared as described for panel A were labeled with cell-permeative fluorescent ligand R110, lysed, and subjected to gradient SDS-PAGE. The gel was visualized for green fluorescence as described in Materials and Methods. (C) Live Jurkat cells expressing Halo-tagged proteins were labeled with R110 Halo ligand, washed, and subjected to flow cytometry. Histograms show FITC fluorescence of the various cells in comparison to the labeled U2OS cells, which have a Halo tag knocked into the CTCF gene. (D) Table showing calculated copy numbers of Halo-tagged proteins based on the absolute values derived from the Halo knock-in cell line. Lentiviral Halo CTCF and Halo SOX2 were quantified from cell populations infected at intermediate and low MOIs, respectively. (E) Confocal microscopy of Jurkat cells lentivirally expressing Halo-LMO2 and labeled with Halo ligand, R110, and nuclear stain (Syto 17 Red). The right panel shows a merged image. Voxel quantification showed that 95% of Halo-LMO2 was nuclear.

Article Snippet: Catalog no. S7579 pBluescript SK Stratagene Iscove's modified Dulbecco's medium (IMDM) Gibco Catalog no. 12200-036 RPMI 1640 Gibco Catalog no. 31800-022 Penicillin-streptomycin solution 10× Corning Catalog no. 30-022-CI Geneticin Gibco Catalog no. 10131-027 0.05% trypsin, 0.53 mM EDTA 1× [−]sodium bicarbonate Corning Catalog no. 20116004 Puromycin dihydrochloride Fisher Bioreagents Catalog no. BP2956-100 Pierce protease inhibitor tablets Thermo Scientific Catalog no. A32965 Hygromycin B-PBS (50 mg/ml) Invitrogen Catalog no. 10687010 Anti-FLAG M2 resin Sigma Catalog no. A2220 Protein A/G resin Santa Cruz Polyvinylidene difluoride (PVDF) membrane GE Catalog no. 10600022 SuperSignal PicoWest Plus Thermo/Pierce Catalog no. 1863099 Experimental models: cell lines Human: HEK 293 ATCC Human: Jurkat ATCC Human: K562 ATCC Human: KOPTK1 ATCC Human: LOUCY ATCC Human: U937 ATCC Human: U2OS C32 Halo-CTCF Hansen et al. ( 27 ) U2OS endogenous knock-in cell line where all endogenous copies of CTCF have been N-terminally tagged with FLAG-HaloTag; clone 32 Software and algorithms Flowjo 10.3 analysis software FlowJo, LLC Contact corresponding author for URL Ideas software Amnis Corporation Contact corresponding author for URL ImageLab 5.2.1 BioRad Contact corresponding author for URL Imaris Bitplane Inc. Other CytoFLEX benchtop cytometer Beckman Contact corresponding author for URL Leica TCS SP8 confocal imaging system Leica Contact corresponding author for URL ImageStream Mk II Amnis Contact corresponding author for URL Open in a separate window Reagents and resources Experimental model and subject details. (i) Cell lines.

Techniques: Recombinant, Transduction, SDS Page, Control, Molecular Weight, Western Blot, Knock-In, Construct, Plasmid Preparation, Expressing, Fluorescence, Labeling, Flow Cytometry, Comparison, Derivative Assay, Infection, Confocal Microscopy, Staining

Journal: Molecular and Cellular Biology

Article Title: LDB1 Enforces Stability on Direct and Indirect Oncoprotein Partners in Leukemia

doi: 10.1128/MCB.00652-19

Figure Lengend Snippet: Reagents and resources

Article Snippet: Catalog no. S7579 pBluescript SK Stratagene Iscove's modified Dulbecco's medium (IMDM) Gibco Catalog no. 12200-036 RPMI 1640 Gibco Catalog no. 31800-022 Penicillin-streptomycin solution 10× Corning Catalog no. 30-022-CI Geneticin Gibco Catalog no. 10131-027 0.05% trypsin, 0.53 mM EDTA 1× [−]sodium bicarbonate Corning Catalog no. 20116004 Puromycin dihydrochloride Fisher Bioreagents Catalog no. BP2956-100 Pierce protease inhibitor tablets Thermo Scientific Catalog no. A32965 Hygromycin B-PBS (50 mg/ml) Invitrogen Catalog no. 10687010 Anti-FLAG M2 resin Sigma Catalog no. A2220 Protein A/G resin Santa Cruz Polyvinylidene difluoride (PVDF) membrane GE Catalog no. 10600022 SuperSignal PicoWest Plus Thermo/Pierce Catalog no. 1863099 Experimental models: cell lines Human: HEK 293 ATCC Human: Jurkat ATCC Human: K562 ATCC Human: KOPTK1 ATCC Human: LOUCY ATCC Human: U937 ATCC Human: U2OS C32 Halo-CTCF Hansen et al. ( 27 ) U2OS endogenous knock-in cell line where all endogenous copies of CTCF have been N-terminally tagged with FLAG-HaloTag; clone 32 Software and algorithms Flowjo 10.3 analysis software FlowJo, LLC Contact corresponding author for URL Ideas software Amnis Corporation Contact corresponding author for URL ImageLab 5.2.1 BioRad Contact corresponding author for URL Imaris Bitplane Inc. Other CytoFLEX benchtop cytometer Beckman Contact corresponding author for URL Leica TCS SP8 confocal imaging system Leica Contact corresponding author for URL ImageStream Mk II Amnis Contact corresponding author for URL Open in a separate window Reagents and resources Experimental model and subject details. (i) Cell lines.

Techniques: Recombinant, Staining, Modification, Protease Inhibitor, Membrane, Knock-In, Software, Cytometry, Imaging