Abstract |
The eucaryotic protein L7, which associates with the large subunit of ribosomes, has been shown to be a major autoantigen in systemic autoimmune arthritis. The N terminus carries a sequence motif that is similar to the leucine zipper domain of eucaryotic transcription factors. This domain promotes the homodimerization of protein L7 through alpha-helical coiled-coil formation and binds to distinct mRNAs, thereby inhibiting their cell-free translation. Using a yeast two-hybrid selection, we have identified from a Jurkat T lymphoma cDNA library ribosomal protein S7 and the multi-zinc finger protein ZNF7 as proteins that interact with protein L7. A fragment of L7 carrying the leucine zipper-like domain is fully sufficient to mediate these interactions. Their potential biological significance is indicated by low apparent dissociation constants of S7-L7 (15 x 10(-9) M) and, respectively, ZNF7-L7 (2 x 10(-9) M) complexes and co-immunoprecipitation of proteins S7, ZNF7, and L7 from a cell lysate with an anti-L7 antibody. We also show that ZNF7-like L7 and S7 can exist in a ribosome-bound form. This study provides further evidence suggesting that L7 is involved in translational regulation through interactions with components of the translational apparatus.
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Authors | S Witte, U Krawinkel |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 272
Issue 35
Pg. 22243-7
(Aug 29 1997)
ISSN: 0021-9258 [Print] United States |
PMID | 9268371
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- DNA-Binding Proteins
- Kruppel-Like Transcription Factors
- RPL7 protein, human
- Ribosomal Proteins
- ZNF7 protein, human
- ribosomal protein S7
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Topics |
- DNA-Binding Proteins
(metabolism)
- Dimerization
- Humans
- Jurkat Cells
- Kruppel-Like Transcription Factors
- Leucine Zippers
- Ribosomal Proteins
(metabolism)
- Ribosomes
(metabolism)
- Zinc Fingers
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