title: The highly related DEAD box RNA helicases p68 and p72 exist as heterodimers in cells.
abstract: The RNA helicases p68 and p72 are highly related members of the DEAD box family of proteins, sharing 90% identity across the conserved core, and have been shown to be involved in both transcription and mRNA processing. We previously showed that these proteins co-localise in the nucleus of interphase cells. In this study we show that p68 and p72 can interact with each other and self-associate in the yeast two-hybrid system. Co-immunoprecipitation experiments confirmed that p68 and p72 can interact in the cell and indicated that these proteins preferentially exist as hetero-dimers. In addition, we show that p68 can interact with NFAR-2, a protein that is also thought to function in mRNA processing. Moreover, gel filtration analysis suggests that p68 and p72 can exist in a variety of complexes in the cell (ranging from approximately 150 to approximately 400 kDa in size), with a subset of p68 molecules being in very large complexes (>2 MDa). The potential to exist in different complexes that may contain p68 and/or p72, together with a range of other factors, would provide the potential for these proteins to interact with different RNA substrates and would be consistent with recent reports implying a wide range of functions for p68/p72.
authors.affiliation: Department of Molecular and Cellular Pathology, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK.
authors.forename: V C
authors.initials: VC
authors.lastname: Ogilvie
authors.forename: B J
authors.initials: BJ
authors.lastname: Wilson
authors.forename: S M
authors.initials: SM
authors.lastname: Nicol
authors.forename: N A
authors.initials: NA
authors.lastname: Morrice
authors.forename: L R
authors.initials: LR
authors.lastname: Saunders
authors.forename: G N
authors.initials: GN
authors.lastname: Barber
authors.forename: F V
authors.initials: FV
authors.lastname: Fuller-Pace
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001667:Binding, Competitive; D002460:Cell Line; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D053487:DEAD-box RNA Helicases; D019281:Dimerization; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D050779:Nuclear Factor 90 Proteins; D010750:Phosphoproteins; D011233:Precipitin Tests; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020365:RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D020798:Two-Hybrid System Techniques
chemical_list: D002868:Chromosomal Proteins, Non-Histone; C429643:ILF3 protein, human; D050779:Nuclear Factor 90 Proteins; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; C047458:fibrillarin; D011494:Protein Kinases; D000251:Adenosine Triphosphatases; C102004:DDX17 protein, human; C506749:Ddx5 protein, human; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases