Fig. 3.

Parkin negatively regulates HIF-1α transcriptional activity. a Myc-Parkin expression inhibited HIF-1α luciferase reporter activities in cells. b Parkin knockdown increased HIF-1α luciferase reporter activities in cells. c Myc-Parkin expression reduced mRNA expression of HIF-1α target genes in cells. d Parkin knockdown increased mRNA expression of HIF-1α target genes in cells. Gene expression was measured by quantitative Taqman real-time PCR and normalized with actin. In c, HIF-1α was knocked down by 2 different shRNA vectors, and in d, HIF-1α and Parkin were knocked down by 2 different shRNA vectors. Similar results were observed for 2 different HIF-1α and Parkin shRNA vectors, and only results from one shRNA vector were presented for the sake of clarity. The data present mean ± S.D. (n = 6). **P < 0.001; two-tailed Student's t test