title: Subcellular distribution of human RDM1 protein isoforms and their nucleolar accumulation in response to heat shock and proteotoxic stress.
abstract: The RDM1 gene encodes a RNA recognition motif (RRM)-containing protein involved in the cellular response to the anti-cancer drug cisplatin in vertebrates. We previously reported a cDNA encoding the full-length human RDM1 protein. Here, we describe the identification of 11 human cDNAs encoding RDM1 protein isoforms. This repertoire is generated by alternative pre-mRNA splicing and differential usage of two translational start sites, resulting in proteins with long or short N-terminus and a great diversity in the exonic composition of their C-terminus. By using tagged proteins and fluorescent microscopy, we examined the subcellular distribution of full-length RDM1 (renamed RDM1alpha), and other RDM1 isoforms. We show that RDM1alpha undergoes subcellular redistribution and nucleolar accumulation in response to proteotoxic stress and mild heat shock. In unstressed cells, the long N-terminal isoforms displayed distinct subcellular distribution patterns, ranging from a predominantly cytoplasmic to almost exclusive nuclear localization, suggesting functional differences among the RDM1 proteins. However, all isoforms underwent stress-induced nucleolar accumulation. We identified nuclear and nucleolar localization determinants as well as domains conferring cytoplasmic retention to the RDM1 proteins. Finally, RDM1 null chicken DT40 cells displayed an increased sensitivity to heat shock, compared to wild-type (wt) cells, suggesting a function for RDM1 in the heat-shock response.
authors: International Agency for Research on Cancer (IARC), 150 Cours Albert Thomas, 69372 Lyon, France.
authors: Lydia
authors: L
authors: Messaoudi
authors: Yun-Gui
authors: YG
authors: Yang
authors: Aiko
authors: A
authors: Kinomura
authors: Diana A
authors: DA
authors: Stavreva
authors: Gonghong
authors: G
authors: Yan
authors: Marie-Line
authors: ML
authors: Bortolin-Cavaillé
authors: Hiroshi
authors: H
authors: Arakawa
authors: Jean-Marie
authors: JM
authors: Buerstedde
authors: Pierre
authors: P
authors: Hainaut
authors: Jérome
authors: J
authors: Cavaillé
authors: Minoru
authors: M
authors: Takata
authors: Eric
authors: E
authors: Van Dyck
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002466:Cell Nucleolus / Q000737:chemistry*; D002467:Cell Nucleus / Q000737:chemistry; D002645:Chickens; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003593:Cytoplasm / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D003609:Dactinomycin / Q000494:pharmacology; D005091:Exons; D017353:Gene Deletion; D018869:Heat-Shock Response; D006801:Humans; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D061988:Proteasome Inhibitors; D020033:Protein Isoforms / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D061988:Proteasome Inhibitors; D020033:Protein Isoforms; C499652:RDM1 protein, human; D012333:RNA, Messenger; C067713:lactacystin; D003609:Dactinomycin; D000111:Acetylcysteine