Nam Lee

Associate Professor, Chemistry and Biochemistry - Med

Extra Info

Degrees and Appointments 

  • B.A. 1997, University of Iowa
  • Ph.D. 2005, University of Iowa
  • Postdoctoral Fellow 2005-2011, Duke University
  • Assistant to Associate Professor, 2011-2017, The Ohio State University
  • Associate Professor, 2017-present, University of Arizona

Field of Study: Biochemistry 

Awards and Honors

  • 2002-2004 Department of Defense Breast Cancer Research Fellowship
  • 2006-2007 Duke Medical Oncology Research Fellow
  • 2008-2010 F32 NIH NRSA Postdoctoral Fellow, NCI
  • 2009 Duke University Bell Award in Basic Cancer Research
  • 2011-2015 K99/R00 NIH Career Development Award, NHLBI

Research Specialties: Metabolism, Signaling, and Regulation Protein and Membrane Biochemistry


My research focuses on understanding how transforming growth factor beta (TGF-beta) signaling controls a wide spectrum of molecular and cellular effects ranging from proliferation to differentiation and cell motility. While gene regulation is the primary mode of signal transduction, often occurring in a highly context-specific manner, our long-term goals include characterizing novel mechanisms by which the canonical effectors, namely the nuclear shuttling SMAD transcription factors and TGF-beta-activated kinase 1 (TAK1), directly modulate cellular activities.

Along with traditional biochemical, biophysical and cellular approaches, we have employed mass spectrometry/proteomics as a key strategy to identify new binding partners and their transcription-independent roles across cell types. We previously discovered that transcriptionally “inactive” SMAD proteins residing in the cytoplasm can influence mitochondrial dynamics through interaction with mitofusin 2 (MFN2), a GTPase critical for mitochondrial fusion in mammalian systems. We found that SMADs do not act alone, but rather as a protein scaffold complex with RIN1 (guanine nucleotide exchange factor) to enhance the MFN2 GTP-binding properties and promote mitofusion.

Likewise through similar methods, we recently characterized new protein interactions between TAK1 and a subset of microtubule modifying enzymes. We are interested in learning how these interactions control microtubule functions including their mechanical stability as well as cellular transport of protein cargo. Collectively, these findings represent major new facets of TGF-beta biology and directions for the lab as we explore how human mutations alter their functional interactions in cancer, metabolic and neurologic diseases.

Ahmed T, Ramonett R, Kwak EA, Kumar S, Flores PC, Ortiz HR, Langlais PR, Mythreye K, Lee NY. Endothelial tip and stalk cell specification requires BMP9-induced bIV-spectrin expression during nascent vessel sprouting. Mol Biol Cell. E23020064. PMID: 37126382. (2023) 


Ahmed T, Flores PC, Pan CC, Ortiz HR, Lee YS, Langlais PR, Mythreye K, Lee NY. EPDR1 is a noncanonical effector of insulin-mediated angiogenesis regulated by an endothelial-specific TGF-β receptor complex. J Biol Chem.298(9):102297. PubMed PMID: 35872017. (2022)  


Kwak EA, Pan CC, Ramonett A, Kumar S, Cruz-Flores P, Ahmed T, Ortiz HR, Lochhead JJ, Ellis NA, Mouneimne G, Georgieva TG, Lee YS, Vanderah TW, Largent-Milnes T, Mohler PJ, Hund TJ, Langlais PR, Mythreye K, Lee NY. βIV-spectrin as a stalk cell-intrinsic regulator of VEGF signaling. Nature Commun. 13(1):1326. PMID: 35288568; PMCID: PMC8921520. (2022)  


Ramonett A, Kwak EA, Ahmed T, Flores PC, Ortiz HR, Lee YS, Vanderah TW, Largent-Milnes T, Kashatus DF, Langlais PR, Mythreye K, Lee NY. Regulation of mitochondrial fission by GIPC-mediated Drp1 retrograde transport. Mol Biol Cell. 1;33(1) PMID: 34705526; PMCID: PMC8886816. (2021)  


Mukhopadhyay H, Lee NY. Multifaceted roles of TAK1 signaling in cancer. Oncogene. 39(7):1402-1413.  Review.PMID: 31695153; PMCID: PMC7023988. (2020)  


Shah N, Kumar S, Pan CC, Bloodworth JC, Streicher JM, Hempel N, Mythreye K, Lee NY. TAK1 activation of alpha-TAT1 and microtubule hyperacetylation control AKT signaling and cell growth. Nature Commun. Apr 27;9(1):1696. PMID: 29703898, PMCID: PMC5923212. (2018)  


Kumar S, Pan CC, Shah N, Wheeler SE, Hoyt KR, Hempel N, Mythreye K, Lee NY. 

Activation of mitofusin2 by Smad2-RIN1 complex during mitochondrial fusion. 

Molecular Cell. 62(4):520-31. PMID: 27184078. (2016)