title: Nuclear transport of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in opossum kidney cells.
abstract: When added to cultured opossum kidney cells, IGF-I is internalized and transported to distinct intracellular compartments that depend on the cell location within the monolayer. In resting cells away from the periphery of the monolayer, IGF-I is internalized by a clathrin coated pit pathway and delivered to the endosomal compartment. In contrast, cells growing at the edges of a monolayer or an experimental wound internalize IGF-I by an alternative route which rapidly delivers IGF-I to the nucleus. Similarly to IGF-I, IGFBP-3 is also internalized and accumulates in the endosomal compartment in resting cells whereas it is targeted to the nucleus in proliferating cells. IGFBP-3, which contains a putative nuclear targeting signal, may act as a carrier for IGF-I nuclear transport. The transport of IGF-I and IGFBP-3 to two different compartments may influence their biological activity.
authors.affiliation: Department of Pharmacokinetics and Metabolism, Genentech, Inc., South San Francisco, CA 94080, USA.
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Fawcett
authors.forename: H R
authors.initials: HR
authors.lastname: Widmer
authors.forename: P J
authors.initials: PJ
authors.lastname: Fielder
authors.forename: R
authors.initials: R
authors.lastname: Rabkin
authors.forename: G A
authors.initials: GA
authors.lastname: Keller
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D005456:Fluorescent Dyes; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009893:Opossums
chemical_list: D005456:Fluorescent Dyes; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I