The proteasome regulatory particle subunit Rpn6 is required for Drosophila development and interacts physically with signalosome subunit Alien/CSN2

Gene. 2002 Oct 2;298(2):109-19. doi: 10.1016/s0378-1119(02)00930-7.


The eukaryotic 26S proteasome plays a central role in ubiquitin-dependent intracellular protein metabolism. The multimeric holoenzyme is composed of two major subcomplexes, known as the 20S proteolytic core particle and the 19S regulatory particle (RP). The RP can be further dissected into two multisubunit complexes, the lid and the base complex. The lid complex shares striking similarities with another multiprotein complex, the COP9 signalosome. Several subunits of both complexes contain the characteristic PCI domain, a structural motif important for complex assembly. The COP9 signalosome was shown to act as a versatile regulator in numerous pathways. To help define the molecular interactions of the signalosome during Drosophila development, we performed a yeast two-hybrid screen to identify proteins that physically interact with subunit 2 of the complex, namely Alien/CSN2. Here, we report that Drosophila Rpn6, a non-ATPase subunit of the RP lid complex, interacts with Alien/CSN2 via its PCI domain. The temporal and spatial expression patterns of Rpn6 and alien/CSN2 overlap on a large scale during development providing additional evidence for their interaction in vivo. Analyses of an Rpn6 P element insertion mutant and newly generated Rpn6 alleles reveal that Rpn6 is essential for Drosophila development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • COP9 Signalosome Complex
  • Cell Survival / genetics
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism*
  • Drosophila / embryology
  • Drosophila / genetics*
  • Drosophila / growth & development
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Embryo, Nonmammalian / metabolism
  • Embryonic Development
  • Gene Expression Regulation, Developmental
  • Genes, Essential / genetics
  • In Situ Hybridization
  • Molecular Sequence Data
  • Multienzyme Complexes / genetics
  • Multienzyme Complexes / metabolism*
  • Mutation
  • Proteasome Endopeptidase Complex
  • Protein Binding
  • Proteins / genetics
  • Proteins / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Repressor Proteins
  • Saccharomyces cerevisiae / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Signal Transduction
  • Two-Hybrid System Techniques


  • Alien protein, Drosophila
  • Drosophila Proteins
  • Multienzyme Complexes
  • Proteins
  • RNA, Messenger
  • Repressor Proteins
  • Rpn6 protein, Drosophila
  • COP9 Signalosome Complex
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex