TY - JOUR
T1 - Activation of the HIF prolyl hydroxylase by the iron chaperones PCBP1 and PCBP2
AU - Nandal, Anjali
AU - Ruiz, Julio C.
AU - Subramanian, Poorna
AU - Ghimire-Rijal, Sudipa
AU - Sinnamon, Ruth Ann
AU - Stemmler, Timothy L.
AU - Bruick, Richard K.
AU - Philpott, Caroline C.
N1 - Funding Information:
We thank Olga Aprelikova, Hye-sik Kong, and Len Neckers for generously providing technical suggestions, cell lines, plasmids, and antibodies. These studies were supported by the Intramural Research Program of NIDDK, NIH (A.N. and C.C.P), and NIH DK068139 (P.S., S.G.-R., and T.L.S.). R.K.B. is the Michael L. Rosenberg Scholar in Medical Research and was supported by the Burroughs Wellcome Fund, NIH grant CA115962, and a National Center for Research Resources Grant (C06-RR15437-01). J.C.R. was supported by the Sara and Frank McKnight Fund for Biomedical Research.
PY - 2011/11/2
Y1 - 2011/11/2
N2 - Mammalian cells express dozens of iron-containing proteins, yet little is known about the mechanism of metal ligand incorporation. Human poly (rC) binding protein 1 (PCBP1) is an iron chaperone that binds iron and delivers it to ferritin, a cytosolic iron storage protein. We have identified the iron-dependent prolyl hydroxylases (PHDs) and asparaginyl hydroxylase (FIH1) that modify hypoxia-inducible factor α (HIFα) as targets of PCBP1. Depletion of PCBP1 or PCBP2 in cells led to loss of PHD activity, manifested by reduced prolyl hydroxylation of HIF1α, impaired degradation of HIF1α through the VHL/proteasome pathway, and accumulation of active HIF1 transcription factor. PHD activity was restored in vitro by addition of excess Fe(II), or purified Fe-PCBP1, and PCBP1 bound to PHD2 and FIH1 in vivo. These data indicated that PCBP1 was required for iron incorporation into PHD and suggest a broad role for PCBP1 and 2 in delivering iron to cytosolic nonheme iron enzymes.
AB - Mammalian cells express dozens of iron-containing proteins, yet little is known about the mechanism of metal ligand incorporation. Human poly (rC) binding protein 1 (PCBP1) is an iron chaperone that binds iron and delivers it to ferritin, a cytosolic iron storage protein. We have identified the iron-dependent prolyl hydroxylases (PHDs) and asparaginyl hydroxylase (FIH1) that modify hypoxia-inducible factor α (HIFα) as targets of PCBP1. Depletion of PCBP1 or PCBP2 in cells led to loss of PHD activity, manifested by reduced prolyl hydroxylation of HIF1α, impaired degradation of HIF1α through the VHL/proteasome pathway, and accumulation of active HIF1 transcription factor. PHD activity was restored in vitro by addition of excess Fe(II), or purified Fe-PCBP1, and PCBP1 bound to PHD2 and FIH1 in vivo. These data indicated that PCBP1 was required for iron incorporation into PHD and suggest a broad role for PCBP1 and 2 in delivering iron to cytosolic nonheme iron enzymes.
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U2 - 10.1016/j.cmet.2011.08.015
DO - 10.1016/j.cmet.2011.08.015
M3 - Article
C2 - 22055506
AN - SCOPUS:80455143216
SN - 1550-4131
VL - 14
SP - 647
EP - 657
JO - Cell Metabolism
JF - Cell Metabolism
IS - 5
ER -