Non-canonical ubiquitylation of the proneural protein Ngn2 occurs in both Xenopus embryos and mammalian cells
| Autor: | Romana Kucerova, Gary S. McDowell, Anna Philpott |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Proteasome Endopeptidase Complex
Embryo Nonmammalian Biophysics Xenopus Nerve Tissue Proteins Xenopus Proteins medicine.disease_cause Biochemistry Embryonal carcinoma Mice Xenopus laevis Ubiquitin medicine Animals Molecular Biology Mutation biology Ubiquitination Cell Biology medicine.disease biology.organism_classification Molecular biology Cell biology P19 cell Neurula Cell culture Cytoplasm biology.protein Female |
| Zdroj: | Biochemical and Biophysical Research Communications. 400:655-660 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/j.bbrc.2010.08.122 |
| Popis: | Poly-ubiquitin chains targeting proteins for 26S proteasomal degradation are classically anchored on internal lysines of substrates via iso-peptide linkages. However recently, linkage of ubiquitin moieties to non-canonical nucleophilic residues, such as cysteines, serines and threonines, has been demonstrated in a small number of cases. Non-canonical ubiquitylation of the proneural protein Ngn2 has previously been seen in Xenopus egg extract, but it was not clear whether such highly unusual modes of ubiquitylation were restricted to the environment of egg cytoplasm. Here we show that Ngn2 is, indeed, ubiquitylated on non-canonical sites in extracts from neurula stage Xenopus embryos, when Ngn2 is usually active. Moreover, in the P19 mammalian embryonal carcinoma cell line capable of differentiating into neurons, xNgn2 is ubiquitylated on both canonical and non-canonical sites. We see that mutation of cysteines alone results stabilisation of the protein in P19 cells, indicating that non-canonical ubiquitylation on these residues normally contributes to the fast turnover of xNgn2 in mammalian cells. |
| Databáze: | OpenAIRE |
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