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Figure 2 | Retrovirology

Figure 2

From: LKB1 tumor suppressor and salt-inducible kinases negatively regulate human T-cell leukemia virus type 1 transcription

Figure 2

SIKs suppress Tax-mediated LTR activation in a kinase-dependent manner. (A) Influence of AMPK. HeLa cells were transfected with pLTR-Luc (100 ng), a fixed amount of pIEX (100 ng) and escalating amounts of AMPK plasmids (25, 50 and 100 ng). Endogenous p-ACC indicates AMPK activity. Two tailed Student's t test was performed (groups 4 and 6: p = 0.16; groups 10 and 12: p = 0.30). (B) Kinase activity of SIK1 is required for suppression. HeLa cells were transfected with pLTR-Luc (100 ng), a fixed amount of pIEX (100 ng) plus pCMV-Tag2-LKB1-WT/D194A (30 ng), and escalating amounts of SIK1 plasmids (25, 50 and 100 ng). p values were calculated for selected groups (13 and 18: 0.00038; 13 and 21: 0.0000030; 13 and 24: 0.000050). (C) Kinase activity of SIK2/3 is required for suppression. HeLa cells were transfected with pLTR-Luc (100 ng), a fixed amount of pIEX (100 ng) and pCMV-Tag2-SIK2-WT/T175D/K49M (30 ng) or pCMV-Tag2-SIK3-WT/T163D/K37M (30 ng). p values were calculated for selected groups (8 and 10: 0.0050: 8 and 12: 0.010; 8 and 13: 0.00030; 8 and 11: 0.25; 8 and 14: 0.37). (D) Suppression of CRTC1- and Tax-mediated LTR activation by activated SIK1. HeLa cells were transfected with pLTR-Luc (100 ng) and a fixed amount of pIEX (100 ng) and pcDNA3.1/V5-CRTC1 (18 ng) or pCMV-Tag2-SIK1-T182D (50 ng). The difference between groups 4 and 8 is statistically significant (p = 0.000054). (E) Cooperation of activated SIK1/2/3. A fixed amount of pIEX (100 ng) and a fixed total amount (30 ng) of pCMV-Tag2-LKB1-WT, pCMV-Tag2-SIK1-T182D, pCMV-Tag2-SIK2-T175D, pCMV-Tag2-SIK3-T163D or their indicated combinations were transfected into HeLa cells. p values were calculated for selected groups (4 and 7: 0.0066; 4 and 8: 0.00046; 7 and 10: 0.00016; 8 and 10: 0.00017).

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