title: Quantitative single particle tracking of NGF-receptor complexes: transport is bidirectional but biased by longer retrograde run lengths.
abstract: The retrograde transport of nerve growth factor (NGF) in neurite-like processes of living differentiated PC12 cells was studied using streptavidin-quantum dots (QDs) coupled to monobiotin-NGF. These reagents were active in differentiation, binding, internalization, and transport. Ten-35% of the QD-NGF-receptor complexes were mobile. Quantitative single particle tracking revealed a bidirectional step-like motion, requiring intact microtubules, with a net retrograde velocity of 0.054+/-0.020 microm/s. Individual runs had a mean velocity of approximately 0.15 microm/s at room temperature, and the run times were exponentially distributed. The photostability and brightness of QDs permit extended real-time analysis of individual QDbNGF- receptor complexes trafficking within neurites.
authors.affiliation: Centro de Microscopías Avanzadas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Pabellón I, Ciudad Universitaria, Buenos Aires, Argentina.
authors.forename: María M
authors.initials: MM
authors.lastname: Echarte
authors.forename: Luciana
authors.initials: L
authors.lastname: Bruno
authors.forename: Donna J
authors.initials: DJ
authors.lastname: Arndt-Jovin
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Jovin
authors.forename: Lía I
authors.initials: LI
authors.lastname: Pietrasanta
mesh_terms: D000818:Animals; D002863:Chromogenic Compounds / Q000493:pharmacokinetics; D004705:Endocytosis; D008870:Microtubules / Q000502:physiology; D046912:Multiprotein Complexes / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism / Q000648:ultrastructure; D016716:PC12 Cells; D011485:Protein Binding; D021381:Protein Transport; D045663:Quantum Dots; D051381:Rats; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods*; D013379:Substrate Specificity
chemical_list: D002863:Chromogenic Compounds; D046912:Multiprotein Complexes; D020800:Receptor, Nerve Growth Factor