title: Binding of hsp90-associated immunophilins to cytoplasmic dynein: direct binding and in vivo evidence that the peptidylprolyl isomerase domain is a dynein interaction domain.
abstract: FKBP52 is a steroid receptor-associated immunophilin that binds via a tetratricopeptide repeat (TPR) domain to hsp90. FKBP52 has also been shown to interact either directly or indirectly via its peptidylprolyl isomerase (PPIase) domain with cytoplasmic dynein, a motor protein involved in retrograde transport of vesicles toward the nucleus. The functional role for the PPIase domain in receptor movement was demonstrated by showing that expression of the PPIase domain fragment of FKBP52 in 3T3 cells inhibits dexamethasone-dependent nuclear translocation of a green fluorescent protein-glucocorticoid receptor chimera. Here, we show that cytoplasmic dynein is co-immunoadsorbed with two other TPR domain proteins that bind hsp90 (the cyclophilin CyP-40 and the protein phosphatase PP5). Both proteins possess PPIase homology domains, and co-immunoadsorption of cytoplasmic dynein with each is blocked by the PPIase domain fragment of FKBP52. Using purified proteins, we show that FKBP52, PP5, and the PPIase domain fragment bind directly to the intermediate chain of cytoplasmic dynein. PP5 colocalizes with both cytoplasmic dynein and microtubules, and expression of the PPIase domain fragment of FKBP52 in 3T3 cells disrupts its cytoskeletal localization. We conclude that the PPIase domains of the hsp90-binding immunophilins interact directly with cytoplasmic dynein and that this interaction with the motor protein is responsible for the microtubular localization of PP5 in vivo.
authors.affiliation: Department of Pharmacology, The University of Michigan Medical School, Ann Arbor, Michigan 48109-0632, USA. mgali@umich.edu
authors.forename: Mario D
authors.initials: MD
authors.lastname: Galigniana
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Harrell
authors.forename: Patrick J M
authors.initials: PJ
authors.lastname: Murphy
authors.forename: Michael
authors.initials: M
authors.lastname: Chinkers
authors.forename: Christine
authors.initials: C
authors.lastname: Radanyi
authors.forename: Jack-Michel
authors.initials: JM
authors.lastname: Renoir
authors.forename: Mingjie
authors.initials: M
authors.lastname: Zhang
authors.forename: William B
authors.initials: WB
authors.lastname: Pratt
mesh_terms: D016475:3T3 Cells; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D001665:Binding Sites; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D000081406:Peptidyl-Prolyl Isomerase F; D021983:Cyclophilins; D003593:Cytoplasm; D003703:Demecolcine / Q000494:pharmacology; D004398:Dyneins / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D049452:Green Fluorescent Proteins; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D020104:Immunophilins / Q000737:chemistry / Q000378:metabolism*; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D018832:Molecular Chaperones; D009687:Nuclear Proteins / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D011233:Precipitin Tests; D021381:Protein Transport; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism; D022021:Tacrolimus Binding Proteins / Q000378:metabolism*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002352:Carrier Proteins; D000081406:Peptidyl-Prolyl Isomerase F; D018841:HSP90 Heat-Shock Proteins; D008164:Luminescent Proteins; D018832:Molecular Chaperones; D009687:Nuclear Proteins; C000631446:PPIF protein, mouse; D049452:Green Fluorescent Proteins; D010749:Phosphoprotein Phosphatases; C089641:protein phosphatase 5; D004398:Dyneins; D021983:Cyclophilins; D022021:Tacrolimus Binding Proteins; C403485:tacrolimus binding protein 4; D020104:Immunophilins; D019696:Peptidylprolyl Isomerase; D003703:Demecolcine