Fig 1.
Induction of KRT16, FAM129A and HKDC1 transcripts by the inhibition of mitochondrial respiratory chain complexes I or III.
Fold changes of KRT16, FAM129A and HKDC1 transcripts in HCT116 cells treated with complex III inhibitor Myxothiazol for 5 h (a, b, c) or with complex I inhibitor Piericidin A for 13 h (d, e, f). The data was obtained by RT-qPCR and processed as described in Materials and Methods.
Fig 2.
Induction of KRT16, FAM129A and HKDC1 transcripts by the UPR to ER stress.
Fold changes of KRT16, FAM129A and HKDC1 transcripts in HCT116 cells treated with Brefeldin A or Tunicamycin for 14 h. The data was obtained by RT-qPCR and processed as described in Materials and Methods.
Fig 3.
ISR is involved in the induction of KRT16, FAM129A and HKDC1 transcripts in response to ER stress.
Fold changes of KRT16 (a), FAM129A (b) and HKDC1 (c) transcripts in HCT116 cells with or without ISRIB and treated with Brefeldin A (BFA) for 8 h as indicated. The data was obtained by RT-qPCR and processed as described in Materials and Methods.
Fig 4.
ATF4-specific RNAi leads to a suppression of FAM129A, KRT16 and HKDC1 induction in response to inhibition of the mitochondrial respiratory chain.
Fold changes of ATF4 (a), FAM129A (b), KRT16 (c) and HKDC1 (d) transcripts in HCT116 cells expressing ATF4 shRNA (ATF4) or control scrambled shRNA (Scr) in response to treatment with Piericidin A for 8 h. The data was obtained by RT-qPCR and processed as described in Materials and Methods.
Fig 5.
ATF4-specific RNAi leads to suppression of FAM129A, KRT16 and HKDC1 transcription activation in response to ER stress.
Fold changes of ATF4 (a), FAM129A (b), KRT16 (c) and HKDC1 (d) transcripts in HCT116 cells expressing ATF4 shRNA (ATF4) or control scrambled shRNA (Scr) in response to treatment with Brefeldin A for 8 h. The data was obtained by RT-qPCR and processed as described in Materials and Methods.
Fig 6.
Ectopic overexpression of ATF4 and ER stress increase levels of Niban protein.
Western analysis of ATF4 and Niban proteins in HCT116 cells overexpressing ATF4 from a plasmid construct (1, 2), or treated with Brifeldin A (BFA) for 16 hours (3, 4). Probing with actin antibodies was carried out as a loading control.
Fig 7.
Impact of ER-stress on ATF4, KRT16, FAM129A and HKDC1 genes expression in HaCaT cells.
Fold changes of KRT16, FAM129A and HKDC1 transcripts in HaCaT cells treated with Brefeldin A or Tunicamycin for 15 h. The data was obtained by RT-qPCR and processed as described in Materials and Methods.
Fig 8.
Ectopic expression of ATF4 induces transcription of KRT16 promoter-driven reporter gene due to the proximal putative ATF4 binding site.
(A) The scheme of the reporter constructs engineered in this study. (B) Relative luciferase activity of reporters with both the distal and the proximal (pGL3-рKRT16(508)), only the proximal (pGL3-рKRT16(471)) or mutated proximal (pGL3-рKRT16(471)mut) putative ATF4-binding sites in transfected HeLa (B) or HCT116 (C) cells overexpressing ATF4 or the empty vector (Control). The reporter activities were normalized to those in the control cells.