Intra- and intersubunit changes accompanying thermal activation of the HtrA2(Omi) protease homotrimer
| Autor: | Barbara Lipinska, Tomasz Wenta, Przemyslaw Glaza, Miroslaw Jarzab, Agnieszka Polit, Magdalena Wysocka, Jerzy Ciarkowski, Joanna Skorko-Glonek, Adam Lesner, Dorota Zurawa-Janicka, Artur Giełdoń |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
medicine.medical_treatment Protein subunit PDZ domain Allosteric regulation TrIQ analysis Biophysics PDZ Domains Peptide binding Biochemistry Protein Structure Secondary Analytical Chemistry Mitochondrial Proteins 03 medical and health sciences Allosteric Regulation HtrA2(Omi) Catalytic Domain medicine Humans Binding site Molecular Biology Serine protease Binding Sites Protease biology Chemistry Serine Endopeptidases Tryptophan Proteolytic enzymes High-Temperature Requirement A Serine Peptidase 2 allosteric regulation Mitochondria HtrA2 activation cascade 030104 developmental biology proteolytic enzyme biology.protein sense organs Peptides Protein Binding |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. 1864:283-296 |
| ISSN: | 1570-9639 |
| Popis: | HtrA2(Omi) protease is involved in the maintenance of mitochondrial homeostasis and stimulation of apoptosis as well as in development of cancer and neurodegenerative disorders. The protein is a homotrimer whose subunits comprise serine protease domain (PD) and PDZ regulatory domain. In the basal, inactive state, a tight interdomain interface limits access both to the PDZ peptide (carboxylate) binding site and to the PD catalytic center. The molecular mechanism of activation is not well understood. To further the knowledge of HtrA2 thermal activation we monitored the dynamics of the PDZ-PD interactions during temperature increase using tryptophan-induced quenching (TrIQ) method. The TrIQ results suggested that during activation the PDZ domain changed its position versus PD inside a subunit, including a prominent change affecting the L3 regulatory loop of PD, and also changed its interactions with the PD of the adjacent subunit (PD*), specifically with its L1* regulatory loop containing the active site serine. The α5 helix of PDZ was involved in both, the intra- and intersubunit changes of interactions and thus seems to play an important role in HtrA2 activation. The amino acid substitutions designed to decrease the PDZ interactions with the PD or PD* promoted protease activity at a wide range of temperatures, which supports the conclusions based on the TrIQ analysis. The model presented in this work describes PDZ movement in relation to PD and PD*, resulting in an increased access to the peptide binding and active sites, and conformational changes of the L3 and L1* loops. |
| Databáze: | OpenAIRE |
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