title: Identification of the T-complex protein as a binding partner for newly synthesized cytoplasmic dynein intermediate chain 2.
abstract: Cytoplasmic dynein is a macromolecular motor complex with diverse functions in eukaryotic cells. Dynein plays essential roles in intracellular transport of organelles and mitosis, mediated in part by interactions between the dynein intermediate chain 2 (IC-2) subunits and adapter proteins that bind specific cargos. In experiments to identify phosphorylation-dependent binding partners for IC-2 we instead identified a phosphorylation-independent binding partner, the cytosolic chaperonin containing T complex protein 1 (CCT). CCT consists of eight subunits (CCT1-8) and facilitates folding of a subset of newly synthesized proteins. We confirmed interactions between IC-2 and CCT5 and CCT8 in co-immunoprecipitation experiments and determined that the C-terminal half of IC-2 is necessary and sufficient to bind CCT8. Interestingly, co-immunoiprecipitation of IC-2 and CCT is abolished by prior cycloheximide treatment of cells, suggesting that CCT participates in folding of nascent IC-2. In vitro translation experiments employing recombinant CCT complex demonstrated that CCT is able to bind newly synthesized IC-2 after release from the ribosome consistent with a role in folding of IC-2.
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
authors.forename: Aysun
authors.initials: A
authors.lastname: Özdemir
authors.affiliation: Department of Material Science and Chemistry, Graduate School of Engineering, University of Hyogo, Himeji, 671-2201, Japan.
authors.forename: Kodai
authors.initials: K
authors.lastname: Machida
authors.affiliation: Department of Material Science and Chemistry, Graduate School of Engineering, University of Hyogo, Himeji, 671-2201, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Imataka
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Stanley Scott Cancer Center, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA. Electronic address: acatli@lsuhsc.edu.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Catling
mesh_terms: D000818:Animals; D001665:Binding Sites; D056404:Chaperonin Containing TCP-1 / Q000378:metabolism*; D056445:Cytoplasmic Dyneins / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism*
chemical_list: D020409:Molecular Motor Proteins; D056404:Chaperonin Containing TCP-1; D056445:Cytoplasmic Dyneins; C584751:Dync1i2 protein, rat
keywords: CCT; Dynein; Dynein intermediate chain; Folding; IC-2; T complex protein 1