Analysis of the Microprocessor in Dictyostelium: The Role of RbdB, a dsRNA Binding Protein.
We identified the dsRNA binding protein RbdB as an essential component in miRNA processing in Dictyostelium discoideum. RbdB is a nuclear protein that accumulates, together with Dicer B, in nucleolar foci reminiscent of plant dicing bodies. Disruption of rbdB results in loss of miRNAs and accumulation of primary miRNAs. The phenotype can be rescued by ectopic expression of RbdB thus allowing for a detailed analysis of domain function. The lack of cytoplasmic dsRBD proteins involved in miRNA processing, suggests that both processing steps take place in the nucleus thus resembling the plant pathway. However, we also find features e.g. in the domain structure of Dicer which suggest similarities to animals. Reduction of miRNAs in the rbdB- strain and their increase in the Argonaute A knock out allowed the definition of new miRNAs one of which appears to belong to a new non-canonical class.
Department of Genetics, FB10, Kassel University, Kassel, Germany.
Doreen
D
Meier
Ribogenetics Biochemistry Laboratory, Department of Life Science and Chemistry, Molecular Life Sciences Research Center, Jacobs University, Bremen, Germany.
Janis
J
Kruse
Department of Genetics, FB10, Kassel University, Kassel, Germany.
Jann
J
Buttlar
Department of Genetics, FB10, Kassel University, Kassel, Germany.
Michael
M
Friedrich
Department of Genetics, FB10, Kassel University, Kassel, Germany.
Fides
F
Zenk
Department of Genetics, FB10, Kassel University, Kassel, Germany.
Benjamin
B
Boesler
Core Unit System Medicine, University of Würzburg, Würzburg, Germany.
Konrad U
0000-0002-1481-2996
KU
Förstner
Ribogenetics Biochemistry Laboratory, Department of Life Science and Chemistry, Molecular Life Sciences Research Center, Jacobs University, Bremen, Germany.
Christian
C
Hammann
Department of Genetics, FB10, Kassel University, Kassel, Germany.
Wolfgang
W
Nellen
D060565:Argonaute Proteins / Q000235:genetics*; D004023:Dictyostelium / Q000235:genetics*; D000066630:Ectopic Gene Expression / Q000235:genetics; D055786:Gene Knockout Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics; D012330:RNA, Double-Stranded / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics*; D043244:Ribonuclease III / Q000235:genetics*
D060565:Argonaute Proteins; D035683:MicroRNAs; D009687:Nuclear Proteins; D012330:RNA, Double-Stranded; D016601:RNA-Binding Proteins; D049452:Green Fluorescent Proteins; D043244:Ribonuclease III