title: Conformational analysis of misfolded protein aggregation by FRET and live-cell imaging techniques.
abstract: Cellular homeostasis is maintained by several types of protein machinery, including molecular chaperones and proteolysis systems. Dysregulation of the proteome disrupts homeostasis in cells, tissues, and the organism as a whole, and has been hypothesized to cause neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). A hallmark of neurodegenerative disorders is formation of ubiquitin-positive inclusion bodies in neurons, suggesting that the aggregation process of misfolded proteins changes during disease progression. Hence, high-throughput determination of soluble oligomers during the aggregation process, as well as the conformation of sequestered proteins in inclusion bodies, is essential for elucidation of physiological regulation mechanism and drug discovery in this field. To elucidate the interaction, accumulation, and conformation of aggregation-prone proteins, in situ spectroscopic imaging techniques, such as Förster/fluorescence resonance energy transfer (FRET), fluorescence correlation spectroscopy (FCS), and bimolecular fluorescence complementation (BiFC) have been employed. Here, we summarize recent reports in which these techniques were applied to the analysis of aggregation-prone proteins (in particular their dimerization, interactions, and conformational changes), and describe several fluorescent indicators used for real-time observation of physiological states related to proteostasis.
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan. akita@sci.hokudai.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Kitamura
authors.affiliation: Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan. nagata@cc.kyoto-su.ac.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nagata
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan. kinjo@sci.hokudai.ac.jp.
authors.forename: Masataka
authors.initials: M
authors.lastname: Kinjo
mesh_terms: D004721:Endoplasmic Reticulum / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019636:Neurodegenerative Diseases / Q000378:metabolism / Q000473:pathology; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D008164:Luminescent Proteins; D011506:Proteins; D011993:Recombinant Fusion Proteins; D013482:Superoxide Dismutase