A novel RING finger protein, human enhancer of invasion 10, alters mitotic progression through regulation of cyclin B levels.
The process of cellular morphogenesis is highly conserved in eukaryotes and is dependent upon the function of proteins that are centrally involved in specification of the cell cycle. The human enhancer of invasion clone 10 (HEI10) protein was identified from a HeLa cell library based on its ability to promote yeast agar invasion and filamentation. Through two-hybrid screening, the mitotic cyclin B1 and an E2 ubiquitin-conjugating enzyme were isolated as HEI10-interacting proteins. Mutation of the HEI10 divergent RING finger motif (characteristic of E3 ubiquitin ligases) and Cdc2/cyclin binding and phosphorylation sites alter HEI10-dependent yeast phenotypes, including delay in G(2)/M transition. In vertebrates, the addition of HEI10 inhibits nuclear envelope breakdown and mitotic entry in Xenopus egg extracts. Mechanistically, HEI10 expression reduces cyclin B levels in cycling Xenopus eggs and reduces levels of the cyclin B ortholog Clb2p in yeast. HEI10 is itself a specific in vitro substrate of purified cyclin B/cdc2, with a TPVR motif as primary phosphorylation site. Finally, HEI10 is itself ubiquitinated in egg extracts and is also autoubiquitinated in vitro. These and other points lead to a model in which HEI10 defines a divergent class of E3 ubiquitin ligase, functioning in progression through G(2)/M.
Toby
Garabet G
GG
Division of Basic Science, Fox Chase Cancer Center, 7701 Burholme Avenue, Philadelphia, PA 19111, USA.
Gherraby
Wahiba
W
Coleman
Thomas R
TR
Golemis
Erica A
EA
D048868:Adaptor Proteins, Signal Transducing; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D019926:Cyclin B / Q000378:metabolism*; D056744:Cyclin B1; D004527:Egg Proteins / Q000378:metabolism; D005260:Female; D016195:G2 Phase / Q000502:physiology*; D015723:Gene Library; D005816:Genetic Complementation Test; D006801:Humans; D008025:Ligases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008677:Metaphase / Q000502:physiology; D008938:Mitosis / Q000502:physiology*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured; D020798:Two-Hybrid System Techniques; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes; D044767:Ubiquitin-Protein Ligases; D014982:Xenopus laevis; D016335:Zinc Fingers / Q000502:physiology*
D048868:Adaptor Proteins, Signal Transducing; C534699:CCNB1 protein, human; C093749:CLB2 protein, S cerevisiae; D018797:Cell Cycle Proteins; D019926:Cyclin B; D056744:Cyclin B1; D004527:Egg Proteins; D009363:Neoplasm Proteins; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; C079437:UBE2L3 protein, human; D044763:Ubiquitin-Conjugating Enzymes; C473026:CCNB1IP1 protein, human; D044767:Ubiquitin-Protein Ligases; D008025:Ligases