title: Ubiquitylation and degradation of serum-inducible kinase by hVPS18, a RING-H2 type ubiquitin ligase.
abstract: Serum-inducible kinase (SNK) is a member of polo-like kinases that serve as regulators of multiple events during cell division. Rapid changes in the activity and abundance of SNK were reported after the serum stimulation and after the activation of synaptic transmission in the brain. Yet the detailed mechanisms that control the level of SNK protein have not been fully elucidated. In this report, we show that the RING-H2 domain of hVPS18 (human vacuolar protein sorting 18) has a genuine ubiquitin ligase (E3) activity. Using the yeast two-hybrid screening, we identify SNK as a candidate substrate of hVPS18. The half-life of SNK is increased in HeLa cells that down-regulated hVPS18 by lentivirus-mediated small hairpin RNA interference. Furthermore, the delayed entry into S phase is observed in HeLa cells overexpressing hVPS18. These results suggest that hVPS18 may play an important role in regulation of SNK activity through its ubiquitin ligase.
authors.affiliation: Department of Neurochemistry, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Yogosawa
authors.forename: Shigetsugu
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: Keiichi I
authors.initials: KI
authors.lastname: Nakayama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kohsaka
authors.forename: Chihiro
authors.initials: C
authors.lastname: Akazawa
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D019556:COS Cells; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000737:chemistry; D002460:Cell Line; D002469:Cell Separation; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D015536:Down-Regulation; D005434:Flow Cytometry; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D016086:Lentivirus / Q000235:genetics; D008715:Methionine / Q000737:chemistry; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D011494:Protein Kinases / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D013997:Time Factors; D014162:Transfection; D020798:Two-Hybrid System Techniques; D025801:Ubiquitin / Q000737:chemistry*; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry; D015854:Up-Regulation; D033921:Vesicular Transport Proteins / Q000737:chemistry*; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D005982:Glutathione Transferase; D008715:Methionine; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases; D033921:Vesicular Transport Proteins; D000097869:Polo-Like Kinase 1; C424437:VPS18 protein, human; C444640:serum-inducible kinase