title: Biophysical methods for the characterization of PTEN/lipid bilayer interactions.
abstract: PTEN, a tumor suppressor protein that dephosphorylates phosphoinositides at the 3-position of the inositol ring, is a cytosolic protein that needs to associate with the plasma membrane or other subcellular membranes to exert its lipid phosphatase function. Upon membrane association PTEN interacts with at least three different lipid entities: An anionic lipid that is present in sufficiently high concentration to create a negative potential that allows PTEN to interact electrostatically with the membrane, phosphatidylinositol-4,5-bisphosphate, which interacts with PTEN's N-terminal end and the substrate, usually phosphatidylinositol-3,4,5-trisphosphate. Many parameters influence PTEN's interaction with the lipid bilayer, for example, the lateral organization of the lipids or the presence of other chemical species like cholesterol or other lipids. To investigate systematically the different steps of PTEN's complex binding mechanism and to explore its dynamic behavior in the membrane bound state, in vitro methods need to be employed that allow for a systematic variation of the experimental conditions. In this review we survey a variety of methods that can be used to assess PTEN lipid binding affinity, the dynamics of its membrane association as well as its dynamic behavior in the membrane bound state.
authors.affiliation: Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01605, USA.
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Harishchandra
authors.affiliation: Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01605, USA.
authors.forename: Brittany M
authors.initials: BM
authors.lastname: Neumann
authors.affiliation: Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01605, USA.
authors.forename: Arne
authors.initials: A
authors.lastname: Gericke
authors.affiliation: University of Massachusetts Medical School, Department of Biochemistry and Molecular Pharmacology, Worcester, MA 01605, USA. Electronic address: Alonzo.Ross@umassmed.edu.
authors.forename: Alonzo H
authors.initials: AH
authors.lastname: Ross
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D008051:Lipid Bilayers / Q000378:metabolism*; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: D008051:Lipid Bilayers; D025521:Tumor Suppressor Proteins; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: Conformational change; PTEN; Peripheral membrane protein; Phosphatase; Single-particle tracking; Spectroscopy