William Montfort

Professor

Degrees and Appointments 

  • Ph.D. 1985, University of Texas, Austin

Field of Study: Biochemistry 

Awards and Honors

  • Outstanding Educator Award (Student Alumni Association), 2001
  • Roche Research Foundation Award for Scientific Exchange, 1998
  • American Cancer Society (Calif. Div.) Senior Fellowship, 1987-1988
  • National Institute of Health Fellowship (declined), 1987
  • Public Health Service Training Grant, 1986
  • University of Texas Professional Development Award, 1984

Research Specialties: Biophysics, Metabolism, Signaling, and Regulation, Protein and Membrane Biochemistry, Structural Biology

Research

My group determines the atomic structures of proteins and seeks to understand how protein structure gives rise to protein function – both in vitro and in vivo. The problems we study have at their heart a fundamental structure-function question but also address questions of importance to human health. Our approaches include X-ray crystallography, transient kinetic measurements, spectroscopy, protein expression, molecular genetics, mouse models in cancer and related techniques and approaches.

We are particularly interested in nitric oxide signaling mechanisms. Nitric oxide (NO) is a small reactive molecule produced by all higher organisms for the regulation of an immensely varied physiology, including blood pressure regulation, memory formation, tissue development and programmed cell death. We are interested in three NO signaling mechanisms: binding of NO to heme, nitrosation (nitrosylation) of cysteines, and inhibition of proteins containing non-heme iron. NO, produced by NO synthase (NOS), binds to soluble guanylyl cyclase (sGC) at a ferrous heme center, either in the same cell or in nearby cells. Binding leads to conformational changes in heme and protein, and induction of the protein’s catalytic function, yielding cGMP. NO can also react with cysteine residues in proteins, giving rise to S-nitroso (SNO) groups that can alter protein function, and to non-heme iron forming inhibitory mono- and dinitrosyl complexes in proteins. We study the mechanistic details surrounding these complexes and the signaling consequences of their formation in cells and animals.

We’ve previously focused on reversible Fe-NO and SNO chemistry in soluble guanylyl cyclase; the nitrophorins, a family of NO transport proteins from blood-sucking insects; and thioredoxin, a cellular reductant. Our crystal structures of nitrophorin 4 extend to resolutions beyond 0.9 angstroms, allowing us to view hydrogens, multiple residue conformations and subtle changes in heme deformation. We were the first to crystallize SNO-modified proteins, including those in the nitrophorins and in human thioredoxin, where we showed the most stable SNO was a buried SNO. Our current focus is on inflammation in cancer, which induces nitric oxide synthase 2 (NOS2 or iNOS) and drives metastasis. In a mouse model for triple negative breast cancer, we showed that loss of NOS2 via gene knockout leads to loss of metastasis to the lung. We seek the underlying mechanism behind this remarkable finding with a current focus on changes in epigenetic gene regulation through inhibition of RNA and DNA demethylases, which contain non-heme iron, and through inhibition of the TCA cycle and oxidative phosphorylation, yielding loss of substrate for the demethylases and a glycolytic phenotype favoring aggressive tumor growth.

Palczewski MB, Kuschman HP, Hoffman B, Kathiresan V, Yang H, Glynn SA, Wilson DL, Kool E, Montfort WR, Chang J, Petenkaya A, Chronis C, Cundari TR, Sappa S, Islam K, McVicar DW, Fan Y, Chen Q, Meerzaman D, Sierk M, Thomas DD. Nitric Oxide Inhibits Ten-Eleven Translocation DNA Demethylases to Regulate 5mC and 5hmC Across the Genome. Nature Comm (2024), in press.

Montfort WR. Per-ARNT-Sim domains in nitric oxide signaling by soluble guanylyl cyclase. J. Mol. Biol (2024), 436:168235. PMID: 37572934. Invited review.


Badgandi HB, Weichsel A, Montfort WR. Nitric Oxide Delivery and Heme-Assisted S-Nitrosation by the Bedbug Nitrophorin. J. Inorg. Biochem. (2023), 246:112263. PMCID: PMC10332259


Chen C-Y, Lee W, Renhowe PA, Jung J, Montfort WR. Solution structures of the Shewanella woodyi H-NOX protein in the presence and absence of soluble guanylyl cyclase stimulator IWP-051. Protein Science (2021), 30:448-463. PMCID: PMC7784750.


Weichsel A, Kievenaar JA, Curry R, Croft JT, and Montfort WR. Instability in a Coiled-Coil Signaling Helix is Conserved for Signal Transduction in Soluble Guanylyl Cyclase. Protein Science (2019), 28:1830-1839. PMCID: PMC6739824.


Wales JA, Chen C-Y, Breci L, Weichsel A, Bernier SG, Sheppeck II JE, Solinga R, Nakai T, Renhowe PA, Jung J, and Montfort WR. Discovery of stimulator binding to a conserved pocket in the heme domain of soluble guanylyl cyclase. J. Biol. Chem. (2018), 293:1850-1864. PMCID: PMC5798312.


Montfort WR, Wales JA, Weichsel A. Structure and Activation of Soluble Guanylyl Cyclase, the Nitric Oxide Sensor. Antioxid. Redox. Signal. (2017) 26:107-121. Epub 2016 Apr 26.  Invited review. PMCID: PMC5240008.


Purohit R, Fritz BG, The J, Issaian A, Weichsel A, David CL, Campbell E, Hausrath AC, Rassouli-Taylor L, Garcin ED, Gage MJ, Montfort WR. YC-1 Binding to the  Subunit of Soluble Guanylyl Cyclase Overcomes Allosteric Inhibition by the  Subunit. Biochemistry (2014) 53:101-114. PMCID: PMC3914721.


Purohit R, Weichsel A, Montfort WR. Crystal Structure of the Alpha Subunit PAS Domain from Soluble Guanylyl Cyclase. Protein Science (2013) 22:1439-1444. PMCID: PMC3795502.


Fritz BG, Hu X, Brailey JL, Berry RE, Walker FA and Montfort WR. Oxidation and Loss of Heme in Soluble Guanylyl Cyclase from Manduca Sexta. Biochemistry (2011), 50:5813–5815. PMCID: PMC3128461.


Singh SK, Roberts SA, McDevitt SF, Weichsel A, Wildner GF, Grass GB, Rensing C, Montfort WR. Crystal Structures of Multicopper Oxidase CueO Bound to Copper (I) and Silver (I): Functional Role of a Methionine-Rich Sequence. J. Biol. Chem. (2011), 286:37849-37857. PMCID: PMC3199526.


Ramanathan S, Mazzalupo S, Boitano S, Montfort WR. Thrombospondin-1 and Angiotensin II Inhibit Soluble Guanylyl Cyclase through an Increase in Intracellular Calcium Concentration. Biochemistry (2011), 50:7787-7799. PMCID: PMC3168727.


Hu X, Feng C, Hazzard JT, Tollin G, Montfort WR. Binding of YC-1 or BAY 41-2272 to Soluble Guanylyl Cyclase Induces a Geminate Phase for Photolyzed CO. J. Am. Chem. Soc. (2008), 130:15748-15749. PMCID2645941. 


Kondrashov DA, and Montfort WR. Nonequilibrium dynamics simulations of nitric oxide release: comparative study of nitrophorin and myoglobin. J. Phys. Chem. B (2007), 111:9244-9252. PMID: 17622170. 


Amoia AM and Montfort WR. Apo-Nitrophorin 4 at Atomic Resolution. Protein Sci. (2007), 16:2076-2081. PMC2206961.Weichsel A, Brailey JL, Montfort WR.  Buried S-Nitrosocysteine Revealed in Crystal Structures of Human Thioredoxin. Biochemistry (2007), 46:1219-1227. PMID: 17260951.  


Weichsel A, Maes EM, Andersen JF, Valenzuela JG, Shokhireva TKh, Walker FA, Montfort WR.  Heme-Assisted S-Nitrosation of a Proximal Thiol in a Nitric Oxide Transport Protein. Proc. Nat. Acad. Sci. USA (2005), 102:594-599. PMID: 15637157.


Maes EM, Roberts SA, Weichsel, A, Montfort, WR.  Ultra-High Resolution Structures of Nitrophorin 4: Heme Distortion in Ferrous CO and NO Complexes. Biochemistry (2005), 44:12690-12699. PMID: 16171383.


Kondrashov, DA, Roberts, SA, Weichsel, A, Montfort, WR.  Protein Functional Cycle Viewed at Atomic Resolution: Conformational Change and Mobility in Nitrophorin 4 as a Function of pH and NO Binding. Biochemistry (2004), 43:13637-13647. PMID: 15504026.


Roberts SA, Weichsel A, Grass G, Thakali K, Hazzard JT, Tollin G, Rensing C, and Montfort WR.  Crystal structure and Electron Transfer Kinetics of CueO, a multicopper oxidase required for copper homeostasis in E. coli., Proc. Nat. Acad. Sci. USA (2002), 99:2766-2771. PMC122422.


Andersen JF & Montfort WR.  Crystal structures of nitrophorin 2: a trifunctional antihemostatic protein from the saliva of Rhodnius prolixus.  J. Biol. Chem. (2000), 275:30496-30503. PMID: 10884386.


Weichsel A, Andersen JF, Roberts SA, and Montfort WR.  Nitric oxide binding to nitrophorin 4 induces complete distal pocket burial. Nature Struct. Biol. (2000), 7:551-554. PMID: 10876239


Sotelo-Mundo R, Ciesla J, Dzik JM, Rode W, Maley F, Maley G, Hardy LW, Montfort WR. Crystal Structures of Rat Thymidylate Synthase Inhibited by Tomudex, a Potent Anticancer Drug. Biochemistry (1999), 38:1087-1094. PMID: 9894005


Weichsel A, Andersen JF, Champagne DE, Walker FA, Montfort WR.  Crystal Structures of a Nitric Oxide Transport Protein from a Blood-Sucking Insect. Nature Struct. Biol. (1998), 5:304-309. PMID: 9546222. 


Hyatt DC, Maley F, Montfort WR. Use of Strain in a Stereospecific Catalytic Mechanism: Crystal Structures of E. coli Thymidylate Synthase Bound to FdUMP and Methylenetetrahydrofolate.  Biochemistry (1997), 36:4585-4594.  PMID: 9109668.


Weichsel A, Gasdaska JR, Powis G, Montfort WR.  Crystal structures of reduced, oxidized, and mutated human thioredoxin: evidence for a functional homodimer. Structure (1996), 4:735-751.  PMID: 8805557.


Weichsel A, Montfort WR.  Ligand-induced distortion of an active site in thymidylate synthase upon binding anticancer drug 1843U89.  Nature Struct. Biol. (1995), 2:1095-1101. PMID: 8846221. 
 

Additional publications can be found here: 
https://scholar.google.com/citations?hl=en&user=t6BhsZoAAAAJ