Gid9, a second RING finger protein contributes to the ubiquitin ligase activity of the Gid complex required for catabolite degradation

• Published in: FEBS letters 2011-12, Vol.585 (24), p.3856-3861
• Main Authors: Braun, Bernhard, Pfirrmann, Thorsten, Menssen, Ruth, Hofmann, Kay, Scheel, Hartmut, Wolf, Dieter H.
• Format: Article
• Language: English
• Subjects: 6-bisphosphatase; Amino Acid Sequence; Animals; Catabolite degradation; Fructose-1; Fructose-1,6-bisphosphatase; Gid ubiquitin ligase; Gluconeogenesis; Glycolysis; Humans; Molecular Sequence Data; Mutagenesis, Site-Directed; Mutation; Protein Multimerization; Protein Structure, Quaternary; Proteolysis; RING finger; RING Finger Domains; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Ubiquitin-Protein Ligases - metabolism; Ubiquitination
• ISSN: 0014-5793; 1873-3468; 1873-3468
• DOI: 10.1016/j.febslet.2011.10.038

► Gid9 is a second subunit of the Gid ubiquitin ligase complex containing a degenerated RING finger domain. ► It forms a dimer with the ubiquitin ligase confering RING finger subunit Gid2. ► Also the RING finger of Gid9 is required for ubiquitin ligase activity in vivo. The two major antagonistic pathways of carbon metabolism in cells, glycolysis and gluconeogenesis, are tightly regulated. In the eukaryotic model organism Saccharomyces cerevisiae the switch from gluconeogenesis to glycolysis is brought about by proteasomal degradation of the gluconeogenic enzyme fructose-1,6-bisphosphatase. The ubiquitin ligase responsible for polyubiquitylation of fructose-1,6-bisphosphatase is the Gid complex. This complex consists of seven subunits of which subunit Gid2/Rmd5 contains a RING finger domain providing E3 ligase activity. Here we identify an additional subunit containing a degenerated RING finger, Gid9/Fyv10. This subunit binds to Gid2/Rmd5. A mutation in the degenerated RING finger of Gid9/Fyv10 abolishes polyubiquitylation and degradation of three enzymes specific for gluconeogenesis. Gid2physically interacts with Gid9 by anti tag coimmunoprecipitation (View interaction)