Profile picture of Scott Hansen

Scott Hansen

Assistant Professor
Biochemistry, Molecular Biology & Biophysics
Chemistry and Biochemistry
Phone: 541-346-7908
Office: 334 Willamette Hall


Ph.D. University of California, San Francisco
B.S. University of California, Davis

Research Interests

Emergent properties and enzymology of membrane proximal signaling reactions
The Hansen lab aims to define the general mechanisms cells use to create dynamic spatial heterogeneity in signaling reactions orchestrated on intracellular membranes. Using supported membrane technology and a variety of fluorescence spectroscopy techniques, we are characterizing how lipid modifying enzymes and other signaling molecules are activated on membrane surfaces. Learning molecular details about individual proteins is the first step towards understanding complex emergent properties, such as spatial pattern formation. Overall, we want to build a systems-level understanding of how membrane proximal signaling reactions are executed in cells and how these processes are perturbed in human disease.
The ability of cells to regulate the localization of molecules in both time and space is the hallmark of cellular organization. During polarized cell migration, for example, cell surface receptors relay information across the plasma membrane to control the activation of numerous phosphatidylinositol phosphate (PIP) lipid kinases and phosphatases. This results in the synthesis of PIP lipids at distinct locations across the plasma membrane. By selectively recruiting cytosolic proteins to the plasma membrane, PIP lipids function as master regulators of protein localization and function. Genetic and environmental perturbations that create imbalances between opposing lipid kinase and phosphatase activities can negatively impact signaling networks that ultimately control cell morphogenesis, metabolism, and differentiation.
Despite the fundamental importance of PIP lipid kinases and phosphatases in biology, many questions remain unanswered concerning their function. What regulates the strength and duration of PIP lipid synthesis reactions in cells? How are micron length scale asymmetries in PIP lipid composition established and maintained across the intracellular membranes? What mechanisms control the dynamic interplay between PIP lipid synthesis and the actin cytoskeleton? To answer these questions, we are building an interdisciplinary team of scientists that use biochemistry, quantitative cell biology, material science, and theory to define the molecular details of membrane signaling events.
To learn more about our future research ambitions and unpublished work, please email Scott Hansen.


(pulled from pubmed)

Mechanism of SOS PR-domain autoinhibition revealed by single-molecule assays on native protein from lysate.
Lee YK, Low-Nam ST, Chung JK, Hansen SD, Lam HYM, Alvarez S, Groves JT
Nat Commun 2017 Apr 28;8:15061
Bacterial Tubulins A and B Exhibit Polarized Growth, Mixed-Polarity Bundling, and Destabilization by GTP Hydrolysis.
Díaz-Celis C, Risca VI, Hurtado F, Polka JK, Hansen SD, Maturana D, Lagos R, Mullins RD, Monasterio O
J Bacteriol 2017 Oct 1;199(19)
Controlling Styrene Maleic Acid Lipid Particles through RAFT.
Smith AAA, Autzen HE, Laursen T, Wu V, Yen M, Hall A, Hansen SD, Cheng Y, Xu T
Biomacromolecules 2017 Oct 9;
Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS.
Huang WY, Yan Q, Lin WC, Chung JK, Hansen SD, Christensen SM, Tu HL, Kuriyan J, Groves JT
Proc Natl Acad Sci U S A 2016 Jul 19;113(29):8218-23
H-Ras forms dimers on membrane surfaces via a protein-protein interface.
Lin WC, Iversen L, Tu HL, Rhodes C, Christensen SM, Iwig JS, Hansen SD, Huang WY, Groves JT
Proc Natl Acad Sci U S A 2014 Feb 25;111(8):2996-3001
Structural and thermodynamic characterization of cadherin·β-catenin·α-catenin complex formation.
Pokutta S, Choi HJ, Ahlsen G, Hansen SD, Weis WI
J Biol Chem 2014 May 9;289(19):13589-601
Molecular kinetics. Ras activation by SOS: allosteric regulation by altered fluctuation dynamics.
Iversen L, Tu HL, Lin WC, Christensen SM, Abel SM, Iwig J, Wu HJ, Gureasko J, Rhodes C, Petit RS, Hansen SD, Thill P, Yu CH, Stamou D, Chakraborty AK, Kuriyan J, Groves JT
Science 2014 Jul 4;345(6192):50-4
In vitro studies of actin filament and network dynamics.
Mullins RD, Hansen SD
Curr Opin Cell Biol 2013 Feb;25(1):6-13
Cytoplasmic actin: purification and single molecule assembly assays.
Hansen SD, Zuchero JB, Mullins RD
Methods Mol Biol 2013;1046:145-70
αE-catenin actin-binding domain alters actin filament conformation and regulates binding of nucleation and disassembly factors.
Hansen SD, Kwiatkowski AV, Ouyang CY, Liu H, Pokutta S, Watkins SC, Volkmann N, Hanein D, Weis WI, Mullins RD, Nelson WJ
Mol Biol Cell 2013 Dec;24(23):3710-20
Differential remodeling of actin cytoskeleton architecture by profilin isoforms leads to distinct effects on cell migration and invasion.
Mouneimne G, Hansen SD, Selfors LM, Petrak L, Hickey MM, Gallegos LL, Simpson KJ, Lim J, Gertler FB, Hartwig JH, Mullins RD, Brugge JS
Cancer Cell 2012 Nov 13;22(5):615-30
Chromosome passenger complexes control anaphase duration and spindle elongation via a kinesin-5 brake.
Rozelle DK, Hansen SD, Kaplan KB
J Cell Biol 2011 Apr 18;193(2):285-94
A novel role for the CBF3 kinetochore-scaffold complex in regulating septin dynamics and cytokinesis.
Gillis AN, Thomas S, Hansen SD, Kaplan KB
J Cell Biol 2005 Dec 5;171(5):773-84