Arabidopsis CBF5 interacts with the H/ACA snoRNP assembly factor NAF1

• Published in: Plant molecular biology Vol. 65; no. 5; pp. 615 - 626
• Main Authors: Lermontova, Inna, Schubert, Veit, Börnke, Frederik, Macas, Jiri, Schubert, Ingo
• Format: Journal Article
• Language: English
• Published: Netherlands Dordrecht : Springer Netherlands 01.11.2007; Springer Nature B.V
• Subjects: Amino Acid Sequence; Arabidopsis; Arabidopsis - metabolism; Arabidopsis Proteins - analysis; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cajal bodies; cell nucleolus; Centromere; Chromosomes; Gene Library; H/ACA snoRNP; Intranuclear Space - chemistry; Luminescent Proteins - analysis; Metazoa; Molecular Sequence Data; Nicotiana - genetics; Plants, Genetically Modified - metabolism; Protein Structure, Tertiary; Proteins; Pseudouridine synthase; Recombinant Fusion Proteins - analysis; RNA, Small Nuclear - analysis; RNA-Binding Proteins - analysis; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Sequence Alignment; Two-Hybrid System Techniques; Yeast; Yeasts
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/s11103-007-9226-z

The conserved protein CBF5, initially regarded as a centromere binding protein in yeast and higher plants, was later found within nucleoli and in Cajal bodies of yeast and metazoa. There, it is assumed to be involved in posttranscriptional pseudouridinylation of various RNA species that might be important for RNA processing. We found EYFP-labeled CBF5 of A. thaliana to be located within nucleoli and Cajal bodies, but neither at centromeres nor somewhere else on chromosomes. Arabidopsis mutants carrying a homozygous T-DNA insertion at the CBF5 locus were lethal. Yeast two-hybrid and mRNA expression analyses demonstrated that AtCBF5 is co-expressed and interacts with a previously uncharacterized protein containing a conserved NAF1 domain, presumably involved in H/ACA box snoRNP biogenesis. The homologous yeast protein has been shown to contribute to RNA pseudouridinylation. Thus, AtCBF5 might have an essential function in RNA processing rather than being a kinetochore protein.