title: Evidence for the association of the human regulatory protein Ki-1/57 with the translational machinery.
abstract: Ki-1/57 is a cytoplasmic and nuclear protein of 57 kDa first identified in malignant cells from Hodgkin's lymphoma. Based on yeast-two hybrid protein interaction we found out that Ki-1/57 interacts with adaptor protein RACK1 (receptor of activated kinase 1), CIRP (cold-inducible RNA-binding protein), RPL38 (ribosomal protein L38) and FXR1 (fragile X mental retardation-related protein 1). Since these proteins are involved in the regulation of translation we suspected that Ki-1/57 may have a role in it. We show by immunoprecipitation the association of Ki-1/57 with FMRP. Confocal microscopy revealed that Ki-1/57 colocalizes with FMRP/FXR1/2 to stress granules. Furthermore Ki-1/57 cosediments with free ribosomal particles and enhances translation, when tethered to a reporter mRNA, suggesting that Ki-1/57 may be involved in translational regulation.
authors.affiliation: Laboratório Nacional de Biociências (LNBio), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, São Paulo, Brazil.
authors.forename: Kaliandra de Almeida
authors.initials: Kde A
authors.lastname: Gonçalves
authors.forename: Gustavo Costa
authors.initials: GC
authors.lastname: Bressan
authors.forename: Angela
authors.initials: A
authors.lastname: Saito
authors.forename: Luis Gustavo
authors.initials: LG
authors.lastname: Morello
authors.forename: Nilson Ivo T
authors.initials: NI
authors.lastname: Zanchin
authors.forename: Jörg
authors.initials: J
authors.lastname: Kobarg
mesh_terms: D000818:Animals; D018053:Arsenites / Q000494:pharmacology; D019556:COS Cells; D002522:Chlorocebus aethiops; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D018006:Myogenic Regulatory Factors / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D016601:RNA-Binding Proteins / Q000378:metabolism; D012270:Ribosomes / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D018053:Arsenites; D051860:Fragile X Messenger Ribonucleoprotein 1; D018006:Myogenic Regulatory Factors; D016601:RNA-Binding Proteins; C096916:FXR1 protein, human; C096915:FXR2 protein, human; C500946:HABP4 protein, human; C015001:arsenite