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Oligoubiquitination of tissue factor on Lys255 promotes Ser253-dephosphorylation and terminates TF release.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 2016 Nov; Vol. 1863 (11), pp. 2846-2857. Date of Electronic Publication: 2016 Sep 04. - Publication Year :
- 2016
-
Abstract
- Restriction of tissue factor (TF) activity at the cell surface and TF release are critical for prevention of excessive coagulation. This study examined the regulation of TF dephosphorylation and its release through ubiquitination. A plasmid containing the sequence to express the tandem protein TF-tGFP was mutated to include an arginine-substitution at Lys255 within TF. MDA-MB-231 cell line, and HCAEC endothelial cells were transfected and subsequently activated with PAR2-agonist peptide. The wild-type and mutant TF-tGFP were immunoprecipitated from the cell lysates and the ubiquitination and phosphorylation state of TF examined. Analysis of the proteins showed that arginine-substitution of Lys255 within TF prevented its ubiquitination while the wild-type TF-tGFP was oligoubiquitinated. The TF-associated oligoubiquitin chain was estimated to contain up to 4 ubiquitin units, with the linkage formed between Lys63 of one ubiquitin unit, and the C-terminus of the next unit. The Lys255→Arg substitution of TF-tGFP prolonged the phosphorylation of Ser253 within TF, compared to the wild-type TF-tGFP, lengthened the presence of TF-tGFP at the cell surface and extended the duration of TF-tGFP release from cells following PAR2 activation. A biotinylated 19-mer peptide corresponding to the C-terminus of TF (TFc) was used as substrate to show that the ubiquitination of TF was mediated by the Ube2D family of E2-enzymes and involved Mdm2. Moreover, double-phosphorylation of TFc was prerequisite for ubiquitination, with subsequent dephosphorylation of Ser253 by phosphatase PP2A. In conclusion, oligoubiquitination of Lys255 within TF permits PP2A to bind and dephosphorylate Ser253 and occurs to terminate TF release and contain its activity.<br /> (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Subjects :
- Cell Line, Tumor
Endothelial Cells drug effects
Female
Humans
Lysine
Oligopeptides pharmacology
Phosphorylation
Protein Binding
Protein Phosphatase 2 metabolism
Proto-Oncogene Proteins c-mdm2 metabolism
Receptor, PAR-2 agonists
Receptor, PAR-2 metabolism
Serine
Thromboplastin chemistry
Thromboplastin genetics
Time Factors
Transfection
Ubiquitination
Blood Coagulation drug effects
Endothelial Cells metabolism
Thromboplastin metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1863
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 27599717
- Full Text :
- https://doi.org/10.1016/j.bbamcr.2016.09.005