Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization
Osteopontin (OPN) is a highly posttranslationally modified protein present in several tissues where it is implicated in numerous physiological processes. OPN primarily exerts its functions through interaction with integrins via the Arg-Gly-Asp and Ser-Val-Val-Tyr-Gly-Leu-Arg sequences located in the...
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| Format: | Online |
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Public Library of Science
2014
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4242673/ |
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pubmed-4242673 |
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pubmed-42426732014-11-26 Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization Christensen, Brian Zachariae, Elias D. Scavenius, Carsten Thybo, Morten Callesen, Morten M. Kløverpris, Søren Oxvig, Claus Enghild, Jan J. Sørensen, Esben S. Research Article Osteopontin (OPN) is a highly posttranslationally modified protein present in several tissues where it is implicated in numerous physiological processes. OPN primarily exerts its functions through interaction with integrins via the Arg-Gly-Asp and Ser-Val-Val-Tyr-Gly-Leu-Arg sequences located in the N-terminal part of the protein. OPN can be polymerized by the cross-linking enzyme transglutaminase 2 (TG2), and polymerization has been shown to enhance the biological activity of OPN. However, little is known about the reactivity and location of the glutamine and lysine residues involved in the TG2-mediated modification of OPN. Here we show that TG2 catalyses the incorporation of 5-(Biotinamido)pentylamine at glutamines in both the N- and C-terminal parts of OPN, whereas TG2 primarily incorporated the glutamine-donor peptide biotinyl-TVQQEL-OH into the C-terminal part of OPN. By mass spectrometric analyses we identified Gln34, Gln42, Gln193 and Gln248 as the major TG2 reactive glutamines in OPN. The distribution of reactive Gln and Lys residues in OPN proved to be important, as the full-length protein but not the physiologically highly active integrin-binding N-terminal part of OPN were able to polymerize in a TG2-mediated reaction. Collectively, these data provide important new molecular knowledge about the mechanism of OPN polymerization. Public Library of Science 2014-11-24 /pmc/articles/PMC4242673/ /pubmed/25419572 http://dx.doi.org/10.1371/journal.pone.0113650 Text en © 2014 Christensen et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Christensen, Brian Zachariae, Elias D. Scavenius, Carsten Thybo, Morten Callesen, Morten M. Kløverpris, Søren Oxvig, Claus Enghild, Jan J. Sørensen, Esben S. |
| spellingShingle |
Christensen, Brian Zachariae, Elias D. Scavenius, Carsten Thybo, Morten Callesen, Morten M. Kløverpris, Søren Oxvig, Claus Enghild, Jan J. Sørensen, Esben S. Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization |
| author_facet |
Christensen, Brian Zachariae, Elias D. Scavenius, Carsten Thybo, Morten Callesen, Morten M. Kløverpris, Søren Oxvig, Claus Enghild, Jan J. Sørensen, Esben S. |
| author_sort |
Christensen, Brian |
| title |
Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization |
| title_short |
Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization |
| title_full |
Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization |
| title_fullStr |
Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization |
| title_full_unstemmed |
Identification of Transglutaminase Reactive Residues in Human Osteopontin and Their Role in Polymerization |
| title_sort |
identification of transglutaminase reactive residues in human osteopontin and their role in polymerization |
| description |
Osteopontin (OPN) is a highly posttranslationally modified protein present in several tissues where it is implicated in numerous physiological processes. OPN primarily exerts its functions through interaction with integrins via the Arg-Gly-Asp and Ser-Val-Val-Tyr-Gly-Leu-Arg sequences located in the N-terminal part of the protein. OPN can be polymerized by the cross-linking enzyme transglutaminase 2 (TG2), and polymerization has been shown to enhance the biological activity of OPN. However, little is known about the reactivity and location of the glutamine and lysine residues involved in the TG2-mediated modification of OPN. Here we show that TG2 catalyses the incorporation of 5-(Biotinamido)pentylamine at glutamines in both the N- and C-terminal parts of OPN, whereas TG2 primarily incorporated the glutamine-donor peptide biotinyl-TVQQEL-OH into the C-terminal part of OPN. By mass spectrometric analyses we identified Gln34, Gln42, Gln193 and Gln248 as the major TG2 reactive glutamines in OPN. The distribution of reactive Gln and Lys residues in OPN proved to be important, as the full-length protein but not the physiologically highly active integrin-binding N-terminal part of OPN were able to polymerize in a TG2-mediated reaction. Collectively, these data provide important new molecular knowledge about the mechanism of OPN polymerization. |
| publisher |
Public Library of Science |
| publishDate |
2014 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4242673/ |
| _version_ |
1613160286682873856 |