The role of the LB structural loop and its interactions with the PDZ domain of the human HtrA3 protease

Tomasz Wenta , Przemysław Glaza , Mirosław Jarząb , Urszula Zarzecka , Dorota Żurawa-Janicka , Adam Lesner , Joanna Skórko-Glonek , Barbara Lipińska

Abstract

Human HtrA3 protease is a proapoptotic protein, involved in embryo implantation and oncogenesis. In stress conditions the protease is activated by removal of its N-terminal domain. The activated form, ΔN-HtrA3L is a homotrimer composed of the protease (PD) and PDZ domains. The LB structural loop of the PD is longer by six amino acid residues than its counterparts of other human HtrA proteins and interacts with the PDZ in a way not observed in other known HtrA structures. By size exclusion chromatography of the ΔN-HtrA3L mutated variants we found that removal of the additional LB loop residues caused a complete loss of the proper trimeric structure while impairing their interactions with the PDZ domain decreased the amount of the trimers. This indicates that the LB loop participates in stabilization of the ΔN-HtrA3L oligomer structure and suggests involvement of the LB-PDZ interactions in the stabilization. Removal of the additional LB loop residues impaired the ΔN-HtrA3L activity against the peptide and protein substrates, including the antiapoptotic XIAP protein, while a decrease in the LB-PDZ interaction caused a diminished efficiency of the peptide cleavage. These results indicate that the additional LB residues are important for the ΔN-HtrA3L proteolytic activity. Furthermore, a monomeric form of the ΔN-HtrA3L is proteolytically inactive. In conclusion, our results suggest that the expanded LB loop promotes the ΔN-HtrA3L activity by stabilizing the protease native trimeric structure.
Author Tomasz Wenta KBOiM
Tomasz Wenta,,
- Department of Biochemistry
, Przemysław Glaza KBOiM
Przemysław Glaza,,
- Department of Biochemistry
, Mirosław Jarząb KBOiM
Mirosław Jarząb,,
- Department of Biochemistry
, Urszula Zarzecka KBOiM
Urszula Zarzecka,,
- Department of Biochemistry
, Dorota Żurawa-Janicka KBOiM
Dorota Żurawa-Janicka,,
- Department of Biochemistry
, Adam Lesner PAB
Adam Lesner,,
- Laboratory of Biochemical Analytics
, Joanna Skórko-Glonek KBOiM
Joanna Skórko-Glonek,,
- Department of Biochemistry
, Barbara Lipińska KBOiM
Barbara Lipińska,,
- Department of Biochemistry
Journal seriesBiochimica et Biophysica Acta (BBA) - Proteins and Proteomics, ISSN 1570-9639
Issue year2017
Vol1865
No9
Pages1141-1151
Publication size in sheets0.5
Keywords in EnglishHtrA proteins, human HtrA3 protease, LB loop, human HtrA3 activity, XIAP proteolysis
DOIDOI:10.1016/j.bbapap.2017.06.013
URL https://doi.org/10.1016/j.bbapap.2017.06.013
Languageen angielski
Score (nominal)30
ScoreMinisterial score = 30.0, 20-12-2017, ArticleFromJournal
Ministerial score (2013-2016) = 30.0, 20-12-2017, ArticleFromJournal
Publication indicators WoS Impact Factor: 2016 = 2.773 (2) - 2016=2.879 (5)
Citation count*1 (2018-08-19)
Cite
Share Share

Get link to the record
msginfo.png


* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.
Back