title: JAB1/CSN5 interacts with the GAL4 DNA binding domain: a note of caution about two-hybrid interactions.
abstract: The Jun activation domain binding protein 1 (JAB1) was first identified as an interaction partner and coactivator of c-Jun. Subsequently, it was found to be a subunit of the COP9 signalosome (CSN) and termed CSN subunit 5 (CSN5). This complex regulates light-mediated development in plants and plays an essential role in a variety of organisms. A striking feature of JAB1/CSN5 is its reported interaction with a wide range of proteins and its modulation of their activity or stability. We applied the yeast two-hybrid system to screen for proteins interacting with the DNA-binding domain of the transcription factor c-Myb and found JAB1/CSN5 among the double-positive clones. To our surprise JAB1/CSN5 was shown to interact with the DNA-binding domain of GAL4 alone and had to be rejected as a false positive in the GAL4-based two-hybrid system. This finding emphasizes the necessity of particular caution when JAB1/CSN5 is found in two-hybrid screenings.
authors.affiliation: Department of Biochemistry, University of Oslo, P.O. Box 1041 Blindern, 0316 Oslo, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Nordgård
authors.forename: Ø
authors.initials: Ø
authors.lastname: Dahle
authors.forename: T Ø
authors.initials: TØ
authors.lastname: Andersen
authors.forename: O S
authors.initials: OS
authors.lastname: Gabrielsen
mesh_terms: D001853:Bone Marrow; D000075686:COP9 Signalosome Complex; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005189:False Positive Reactions; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D015723:Gene Library; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D010447:Peptide Hydrolases; D017434:Protein Structure, Tertiary; D020598:Proto-Oncogene Proteins c-myb / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D015003:Yeasts
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D047908:Intracellular Signaling Peptides and Proteins; D020598:Proto-Oncogene Proteins c-myb; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA; D010447:Peptide Hydrolases; C501488:COPS5 protein, human; D000075686:COP9 Signalosome Complex