title: Abundant class of non-coding RNA regulates development in the social amoeba Dictyostelium discoideum.
abstract: Non-coding (nc)RNAs are important players in most biological processes. Although small RNAs such as microRNAs and small interfering RNAs have emerged as exceptionally important regulators of gene expression, great numbers of larger ncRNAs have also been identified. Many of these are abundant and differentially expressed but their functions have in most cases not been elucidated. The social amoeba Dictyostelium discoideum contain the ncRNAs commonly found in eukaryotes. In addition, we previously reported the identification of two novel classes of 42-65 nt long stem-loop forming RNAs, Class I and Class II RNAs, with unknown function. In this study we have further characterized these abundant ncRNAs, which are down regulated during development. We have confirmed expression of 29 Class I RNAs and experimentally verified the formation of the computationally predicted short conserved stem structure. Furthermore, we have for the first time created knockout strains for several small ncRNA genes in D. discoideum and found that deletion of one of the Class I RNAs, DdR-21, results in aberrant development. In addition we have shown that this Class I RNA forms a complex with one or several proteins but do not appear to be associated with ribosomes or polysomes. In a pull down assay, several proteins interacting with DdR-21 were identified, one of these has two RNA recognition motifs (RRMs). The purified RRM containing protein was demonstrated to bind directly and specifically to DdR-21.
authors.affiliation: Department of Molecular Biology, Biomedical Center, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Lotta
authors.initials: L
authors.lastname: Avesson
authors.forename: Heiko T
authors.initials: HT
authors.lastname: Schumacher
authors.forename: Pierre
authors.initials: P
authors.lastname: Fechter
authors.forename: Pascale
authors.initials: P
authors.lastname: Romby
authors.forename: Ulf
authors.initials: U
authors.lastname: Hellman
authors.forename: Fredrik
authors.initials: F
authors.lastname: Söderbom
mesh_terms: D001483:Base Sequence; D017124:Conserved Sequence; D004023:Dictyostelium / Q000235:genetics* / Q000254:growth & development*; D024202:Electrophoretic Mobility Shift Assay; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010641:Phenotype; D011132:Polyribosomes / Q000378:metabolism; D022661:RNA, Untranslated / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
chemical_list: D022661:RNA, Untranslated; D016601:RNA-Binding Proteins