Journal: mBio

Article Title: Genome-Wide siRNA Screen Identifies Complementary Signaling Pathways Involved in Listeria Infection and Reveals Different Actin Nucleation Mechanisms during Listeria Cell Invasion and Actin Comet Tail Formation

doi: 10.1128/mBio.00598-15

Figure Lengend Snippet: Contributions of the different subunits of the Arp2/3 complex to Listeria invasion. Subunits of the Arp2/3 complex were knocked down by siRNA transfection of HeLa cells either individually (A) or in combination (B). One hour after infection with Listeria , cells were washed with gentamicin in order to kill extracellular bacteria, and Listeria entry was measured by counting CFU. Bars represent the mean and standard error of the mean (SEM) from 3 experiments. Significant differences (Student’s t test) from the scramble treatments are indicated as ** ( P < 0.01) and * ( P < 0.05). (C) HeLa cells infected with Listeria for 10 min were stained for actin (red) and the Arp2/3 complex subunit p20 (left panel, green) or p16 (right panel, green). Bars, 5 µm.

Article Snippet: For staining at bacterial entry sites of individual Arp2/3 subunits (rabbit polyclonal anti-p20 antibody [Santa Cruz sc-68394] or mouse monoclonal anti-p16 antibody [Santa Cruz sc-166760]) or for SPIRE2 (rabbit polyclonal AP54024PU-N; Acris GmbH), cells were infected at an MOI of 25 and fixed 10 min postinfection; for staining of Arp2/3 subunits at actin comet tails, cells were infected at an MOI of 5 and fixed 6 h postinfection.

Techniques: Transfection, Infection, Bacteria, Staining

Journal: mBio

Article Title: Genome-Wide siRNA Screen Identifies Complementary Signaling Pathways Involved in Listeria Infection and Reveals Different Actin Nucleation Mechanisms during Listeria Cell Invasion and Actin Comet Tail Formation

doi: 10.1128/mBio.00598-15

Figure Lengend Snippet: Contributions of the different subunits of the Arp2/3 complex to actin comet tail formation by Listeria . (A) Examples of images from validation experiments for actin and Listeria upon inactivation of each subunit of the Arp2/3 complex. Bar, 5 µm (B) Percentage of Listeria cells displaying long actin tails, short tails, full actin clouds, partial clouds, or no actin association upon inactivation of Arp2, Arp3, p41 (both subunits simultaneously), p34, p21, p20, and p16. Bars represent the means from 4 experiments. (C) HeLa cells infected with Listeria for 6 h and stained for actin (red) and for the Arp2/3 complex subunit p20 (left panel, green) or p16 (right panel, green). Bars, 5 µm; insert bar left, 2 µm; insert bar right, 1 µm.

Article Snippet: For staining at bacterial entry sites of individual Arp2/3 subunits (rabbit polyclonal anti-p20 antibody [Santa Cruz sc-68394] or mouse monoclonal anti-p16 antibody [Santa Cruz sc-166760]) or for SPIRE2 (rabbit polyclonal AP54024PU-N; Acris GmbH), cells were infected at an MOI of 25 and fixed 10 min postinfection; for staining of Arp2/3 subunits at actin comet tails, cells were infected at an MOI of 5 and fixed 6 h postinfection.

Techniques: Biomarker Discovery, Infection, Staining