Journal: Proceedings of the National Academy of Sciences of the United States of America
Article Title: Cytomegalovirus disrupts Lamin A/C to control microtubule-mediated nuclear movement and cell migration
doi: 10.1073/pnas.2507831122
Figure Lengend Snippet: The effects of Lamin A/C mutants and SUN2 expression on actin filaments in HCMV-infected cells. ( A – C ) NHDFs stably expressing eGFP-tagged Lamin A/C variants; WT, nonphosphorylatable alanine mutant (S22A), or head and tail deletion mutant (ΔHC) were infected with TB40/E-UL99-mCherry at MOI 5 for 6 d. Cells were fixed in methanol (which quenches fluorescent proteins) and stained with antibodies against actin (green), gB (red), and GFP (turquoise), while DNA was stained with Hoechst (blue). ( A ) Images are representative of multiple fields of view derived from at least three independent experiments. ( B ) Enlarged examples of merged images from A which illustrate the partial restoration of actin filaments in some infected cells expressing the Lamin A/C S22A mutant; white arrows show examples of clear filaments while red arrows show examples of weak to no filament restoration. ( C ) Quantification of actin caps. n = 150 cells from three independent replicate experiments (wt: 1/50, 2/50, 1/50; S22A: 25/50, 20/50, 22/50, ΔHC: 0/50, 0/50, 1/50). Bars represent mean ± SEM; ns = not significant, **** P < 0.00001, one-way ANOVA test. ( D ) Lamin A/C expression does not restore SUN2 expression in infected cells. Lamin A/C-expressing cells were infected as described in A – C and then fixed and stained with antibodies against SUN2 (green), gB (red), and GFP (turquoise), while DNA was stained with Hoechst (blue). Representative images are shown from three independent replicate experiments. Note that methanol fixation was required for SUN2 imaging and incomplete quenching results in residual detection of concentrated GFP signal with the Lamin A/C-ΔHC variant, but its pattern is distinct and does not interfere with SUN2 detection. ( E and F ) SUN2 expression does not restore actin caps in infected cells. Control NHDFs or NHDFs expressing flag-tagged SUN2 were infected at MOI 5 for 6d then fixed and stained with antibodies against actin (green), gB (red), and Flag (turquoise), while DNA was stained with Hoechst (blue). ( E ) Representative images of uninfected or infected cells. ( F ) Quantification of actin caps in control or SUN2-expressing NHDFs infected with HCMV from three independent replicate experiments (control NHDFs: Mock; 55/35, 50/50, 44/44, or HCMV infected; 0/36, 0/44, 0/40; SUN2-expressing NHDFs: Mock; 47/47, 55/55, 48/48, or HCMV infected; 0/52, 0/47, 0/50). Bars represent mean ± SEM; **** P < 0.0001, two-way ANOVA test.
Article Snippet: The primary antibodies used for immunoblotting were Ac-K40 tubulin (Sigma-Aldrich: T6793), HCMV IE1/2 (Abcam: ab53495), SUN1 (Novus Biologicals: NBP1-87396), UL44 (Virusys: CA006); Lamin A/C (Proteintech: 10298-1-AP); Lamin B1 (Proteintech: 12987-1-AP); SUN2 (Novus Biologicals: NBP1-58289); gL [Hybridoma from the Chan Lab ( )], eIF4E (BD transduction laboratories: 610270), GFP (Cell Signaling Technologies: 2956S) and β-Actin (CST: 3700S).
Techniques: Expressing, Infection, Stable Transfection, Mutagenesis, Staining, Derivative Assay, Imaging, Variant Assay, Control