You can manage bookmarks using lists, please log in to your user account for this.
Media type:
E-Article
Title:
Identification of novel dipeptidyl peptidase 9 substrates by two‐dimensional differential in‐gel electrophoresis
Contributor:
Zhang, Hui;
Maqsudi, Sadiqa;
Rainczuk, Adam;
Duffield, Nadine;
Lawrence, Josie;
Keane, Fiona M.;
Justa‐Schuch, Daniela;
Geiss‐Friedlander, Ruth;
Gorrell, Mark D.;
Stephens, Andrew N.
Published:
Wiley, 2015
Published in:
The FEBS Journal, 282 (2015) 19, Seite 3737-3757
Language:
English
DOI:
10.1111/febs.13371
ISSN:
1742-464X;
1742-4658
Origination:
Footnote:
Description:
<jats:p>Dipeptidyl peptidase 9 (<jats:styled-content style="fixed-case">DPP</jats:styled-content>9) is a member of the S9B/<jats:styled-content style="fixed-case">DPPIV</jats:styled-content> (<jats:styled-content style="fixed-case">DPP</jats:styled-content>4) serine protease family, which cleaves N‐terminal dipeptides at an Xaa‐Pro consensus motif. Cytoplasmic <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 has roles in epidermal growth factor signalling and in antigen processing, whilst the role of the recently discovered nuclear form of <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 is unknown. Mice lacking <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 proteolytic activity die as neonates. We applied a modified 2D differential in‐gel electrophoresis approach to identify novel <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 substrates, using mouse embryonic fibroblasts lacking endogenous <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 activity. A total of 111 potential new <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 substrates were identified, with nine proteins/peptides confirmed as <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 substrates by <jats:styled-content style="fixed-case">MALDI</jats:styled-content>‐<jats:styled-content style="fixed-case">TOF</jats:styled-content> or immunoblotting. Moreover, we also identified the dipeptide Val‐Ala as a consensus site for <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 cleavage that was not recognized by <jats:styled-content style="fixed-case">DPP</jats:styled-content>8, suggesting different <jats:italic>in vivo</jats:italic> roles for these closely related enzymes. The relative kinetics for the cleavage of these nine candidate substrates by <jats:styled-content style="fixed-case">DPP</jats:styled-content>9, <jats:styled-content style="fixed-case">DPP</jats:styled-content>8 and <jats:styled-content style="fixed-case">DPP</jats:styled-content>4 were determined. This is the first identification of <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 substrates from cells lacking endogenous <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 activity. These data greatly expand the potential roles of <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 and suggest different <jats:italic>in vivo</jats:italic> roles for <jats:styled-content style="fixed-case">DPP</jats:styled-content>9 and <jats:styled-content style="fixed-case">DPP</jats:styled-content>8.</jats:p>