Journal: MedComm
Article Title: Host Translational Control by Stress Granules Promotes Mycobacterium tuberculosis Pathogenesis
doi: 10.1002/mco2.70479
Figure Lengend Snippet: SGs impair mitochondrial complex I activity during Mtb infection. (A) Scheme illustrating the breakdown of oxygen consumption following the addition of the specified inhibitors for assessing oxygen consumption rates (OCRs). (B) OCRs in WT and SG neg macrophages infected with Mtb (MOI 1). Cells were transfected with either siControl (left) or siG3bp1/2 (right) for 48 h before infection. (C–E) Quantification of relative basal (C), maximal (D), and ATP‐linked respirations (E) from (B). Normalized to each UN control (pink‐colored dotted line). Pink p value versus UN, black p value versus siCont. n.s., nonsignificant, * p < 0.05, ** p < 0.01. N = 3. (F) Mitochondrial membrane potential (JC‐1 red/green ratio) in infected WT and SG neg BMDMs (MOI 1; normalized to UN; pink dotted line). n.s., nonsignificant, **** p < 0.0001. N = 3. (G) Intracellular ATP concentrations in infected WT and SG neg BMDMs (MOI 1). **** p < 0.0001. N = 3. (H) Lactate secretion from UN or Mtb‐infected WT and SG neg BMDMs (MOI 1). n.s., nonsignificant, * p < 0.05, ** p < 0.01. N = 3. (I) STRING analysis (v11.5) of 37 proteins upregulated in SG neg BMDMs and simultaneously present in the SG proteome, grouped into translation (Cluster 1), mitochondria (Cluster 2), and nuclear import complex (Cluster 3). (J) Immunoblot of whole‐cell lysate (WCL), cytosolic fraction, and mitochondria fraction from Mtb‐infected WT and SG neg BMDMs (MOI 1, 12 hpi). (K) Immunofluorescence analysis of G3bp1‐Ndufa12 colocalization in Mtb‐infected WT and SG neg BMDMs (MOI 1, 12 hpi); line profiles show fluorescence intensity (white arrow). Scale bar indicates 5 µm. (L) Mitochondrial complex I activity in Mtb‐infected WT and SG neg BMDMs (MOI 1, 12 hpi); rotenone as positive control. Relative mitochondrial complex I activity is plotted, compared to uninfected siControl cells. n.s., nonsignificant, **** p < 0.0001. N = 3.
Article Snippet: The following primary antibodies were used for immunofluorescence analysis: mouse anti‐α‐Tubulin (CST, 3873), rabbit anti‐β‐Actin (CST, 4970), rabbit anti‐G3bp1 (abcam, ab181150), mouse anti‐Eif3η (SCT, sc‐137214), mouse anti‐G3bp1 (SCT, sc‐365338), rabbit anti‐G3bp2 (CST, 31799), rabbit anti‐Rack1 (abcam, ab62735), mouse anti‐Pabp1 (SCT, sc‐166381), mouse anti‐Puromycin (Millipore, MABE343), mouse anti‐Raptor (SCT, sc‐81537), rabbit anti‐mTOR (CST, 2983), rabbit anti‐Astrin (Proteintech, 14726‐1‐AP), and rabbit anti‐Ndufa12 (abcam, ab192617).
Techniques: Activity Assay, Infection, Transfection, Control, Membrane, Western Blot, Immunofluorescence, Fluorescence, Positive Control