Research Interests: Molecular mechanisms of the hypoxic response.
Key words: hypoxia, HIF, PHD2, prolyl hydroxylation, gene regulation, human high altitude adaptation
Research Details: An important cellular response to hypoxia is the activation of the transcription Hypoxia Inducible Factor (HIF). HIF is a master regulator of the hypoxic response and upregulates many genes involved in hypoxic adaptation, including those encoding for enzymes of glycolysis, erythropoietin, endothelin, and vascular endothelial growth factor. HIF is regulated by a distinctive mechanism. Under normoxic conditions, the enzyme PHD2 prolyl hydroxylates the alpha subunit of HIF (HIF-α), which in turn constitutively targets HIF-α for degradation by the ubiquitin-proteasome pathway. Under hypoxic conditions, this modification is inhibited, thereby allowing HIF-α to escape degradation and activate transcription. We are interested in understanding mechanisms by which PHD2 is regulated, and in understanding the physiologic relevance of the pathway. We have an ongoing collaboration with Professor Terence Lappin’s group at Belfast City Hospital and Queen’s University Belfast examining the molecular basis of idiopathic erythrocytosis, and this has identified critical roles for PHD2 and HIF-2α in the control of red cell mass in humans. We are also interested in understanding how this pathway is genetically altered in human populations that have adapted to the chronic hypoxia of high altitude. Tibetans possess PHD2 mutations. We have found that this results in differential effects on the interactions of PHD2 with two proteins, p23 and NACA. This could account for why Tibetans have augmented hypoxic ventilatory responses but are not predisposed to erythrocytosis. Andeans possess a HIF-2α mutation. We have found that this impairs heterodimerization with ARNT and results in a partial loss of function. These studies have provided insights into how the HIF pathway is altered in humans. We employ biochemical, molecular biologic, and mouse model approaches.
Frank Lee (Principal investigator)
Daisheng Song (Senior Research Investigator)
Daisy Lockshire (Undergraduate)
Jake Brewington (Undergraduate)
Dawn Williams (Administrative Assistant)
Medical (autopsy) pathology
Jorgensen, K.#, Song, D.#, Weinstein, J., Garcia, O.A., Pearson, L.N., Inclan, M., Rivera-Chira, M., Leon-Velarde, F., Kiyamu, M., Brutsaert, T.D., Bigham, A.W.*, and Lee, F.S.*: High-Altitude Andean H194R HIF2A Allele is a Hypomorphic Allele. Mol. Biol. Evol. 40: msad162, July 2023 Notes: #These authors contributed equally to this work. *These authors jointly supervised the work, corresponding authors.
Song D., Peng K., Palmer B.E., & Lee F.S.: The ribosomal chaperone NACA recruits PHD2 to cotranslationally modify HIF-α
EMBO J 41: e112059, November 2022.
Song, D., Bigham, A.W., & Lee, F.S.: High-altitude deer mouse Hypoxia inducible factor-2α shows defective interaction with CREB-binding protein. J. Biol. Chem. 296: 100461, Feb 2021.
Song, D., Navalsky, B.E., Guan, W., Ingersoll, C., Wang, T., Loro, E., Eeles, L., Matchett, K.B., Percy, M.J., Medina, R.J., Khurana, T.S., Bigham, A.W., Lappin, T.R., & Lee, F.S.: Tibetan PHD2, an allele with loss of function properties. Proc. Natl. Acad. Sci. USA 117: 12230-12238, June 2020.
Arsenault, P.R., Song, D., Chung, Y.J, Khurana, T.S., & Lee, F.S. : The Zinc Finger of Prolyl Hydroxylase Domain Protein 2 is Essential for Efficient Hydroxylation of Hypoxia Inducible Factor-alpha. Mol. Cell. Biol. 36(18): 2328-2343, Aug 2016 Notes: doi: 10.1128/MCB.00090-16. Print 2016 Sep 15.
Bigham, A.W., & Lee, F.S.: Human high-altitude adaptation: forward genetics meets the HIF pathway. Genes & Dev 28(20): 2189-2204, Oct 2014 Notes: doi: 10.1101/gad.250167.114.
Song, D., Li, L.-S., Arsenault, P.R., Tan, Q., Bigham, A.W., Heaton-Johnson, K.J., Master, S.R., & Lee, F.S. : Defective Tibetan PHD2 Binding to p23 Links High Altitude Adaption to Altered Oxygen Sensing
J. Biol. Chem. 289(21): 14656–14665, May 2014 Notes: doi: 10.1074/jbc.M113.541227. Epub 2014 Apr 7.
Percy, M.J., Furlow, P.W., Lucas, G.W., Li, X., Lappin, T.R.J., McMullin, M.F., & Lee, F.S. : A gain of function mutation in the HIF2A gene in familial erythrocytosis. N Engl J Med 358(2): 162-168, Jan 2008 Notes: Cited as “Exceptional” by Faculty of 1000 Medicine. doi: 10.1056/NEJMoa073123.
Percy M.J., Zhao Q., Flores A., Harrison C., Lappin T.R., Maxwell P.H., McMullin M.F.*, & Lee F.S.*: A family with erythrocytosis establishes a role for prolyl hydroxylase domain protein 2 in oxygen homeostasis. Proc Natl Acad Sci U S A 103(3): 654-659, Jan 2006 Notes: Comment in J. Am. Soc. Nephrol. *Equal senior coauthors. Epub 2006 Jan 9.
Yu, F., White, S.B., Zhao, Q., & Lee, F.S.: HIF-1α Binding to VHL is Regulated by Stimulus-Sensitive Proline Hydroxylation. Proc. Natl. Acad. Sci. USA 98(17): 9630-9635, Aug 2001.
back to top
Last updated: 10/10/2023
The Trustees of the University of Pennsylvania