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. 2011 Jul 13;6(7):e22107. doi: 10.1371/journal.pone.0022107

Figure 2. Oxygen-independent regulation of HELZ.

Figure 2

(A) Immunoblot analysis of HEK293 cells cultured under normoxic or hypoxic conditions for the indicated time periods. The stable HELZ shRNA clone 4–10 and the Hodgkin's lymphoma-derived cell line DEV containing a homozygous deletion on chromosome 17 served as controls for reduced and absent HELZ protein levels, respectively. The Hodgkin's lymphoma derived cell line L428 served as positive control. (B) Transcript levels of HELZ were analyzed in HEK293 cells by RT-qPCR. Cells were exposed to hypoxia (0.2% O2) for up to 48 hours and PHD2 served as hypoxia-inducible control. (C) Total RNA was extracted from tissue samples of various organs from mice exposed to inspiratory air (0% FiCO) or 0.1% carbon monoxide (0.1% FiCO) for 4 hours and HELZ transcript levels were quantified by RT-qPCR and normalized to ribosomal protein S12 mRNA levels. (D) MCF-7 cells were cultured under 20% O2 or 0.2% O2 for 18 hours, fixed, and HELZ as well as HIF-1α protein visualized by indirect immunofluorescence.