Cargando…
Sequential Unfolding Mechanisms of Monomeric Caspases
[Image: see text] Caspases are evolutionarily conserved cysteinyl proteases that are integral in cell development and apoptosis. All apoptotic caspases evolved from a common ancestor into two distinct subfamilies with either monomeric (initiators) or dimeric (effectors) oligomeric states. The regula...
Autores principales: | , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2023
|
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10286309/ https://www.ncbi.nlm.nih.gov/pubmed/37337671 http://dx.doi.org/10.1021/acs.biochem.3c00004 |
_version_ | 1785061718889594880 |
---|---|
author | Joglekar, Isha Clark, A. Clay |
author_facet | Joglekar, Isha Clark, A. Clay |
author_sort | Joglekar, Isha |
collection | PubMed |
description | [Image: see text] Caspases are evolutionarily conserved cysteinyl proteases that are integral in cell development and apoptosis. All apoptotic caspases evolved from a common ancestor into two distinct subfamilies with either monomeric (initiators) or dimeric (effectors) oligomeric states. The regulation of apoptosis is influenced by the activation mechanism of the two subfamilies, but the evolution of the well-conserved caspase-hemoglobinase fold into the two subfamilies is not well understood. We examined the folding landscape of monomeric caspases from two coral species over a broad pH range of 3–10.5. On an evolutionary timescale, the two coral caspases diverged from each other approximately 300 million years ago, and they diverged from human caspases about 600 million years ago. Our results indicate that both proteins have overall high stability, ∼15 kcal mol(–1), near the physiological pH range (pH 6–8) and unfold via two partially folded intermediates, I(1) and I(2*), that are in equilibrium with the native and the unfolded state. Like the dimeric caspases, the monomeric coral caspases undergo a pH-dependent conformational change resulting from the titration of an evolutionarily conserved site. Data from molecular dynamics simulations paired with limited proteolysis and MALDI-TOF mass spectrometry show that the small subunit of the monomeric caspases is unstable and unfolds prior to the large subunit. Overall, the data suggest that all caspases share a conserved folding landscape, that a conserved allosteric site can be fine-tuned for species-specific regulation, and that the subfamily of stable dimers may have evolved to stabilize the small subunit. |
format | Online Article Text |
id | pubmed-10286309 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-102863092023-06-23 Sequential Unfolding Mechanisms of Monomeric Caspases Joglekar, Isha Clark, A. Clay Biochemistry [Image: see text] Caspases are evolutionarily conserved cysteinyl proteases that are integral in cell development and apoptosis. All apoptotic caspases evolved from a common ancestor into two distinct subfamilies with either monomeric (initiators) or dimeric (effectors) oligomeric states. The regulation of apoptosis is influenced by the activation mechanism of the two subfamilies, but the evolution of the well-conserved caspase-hemoglobinase fold into the two subfamilies is not well understood. We examined the folding landscape of monomeric caspases from two coral species over a broad pH range of 3–10.5. On an evolutionary timescale, the two coral caspases diverged from each other approximately 300 million years ago, and they diverged from human caspases about 600 million years ago. Our results indicate that both proteins have overall high stability, ∼15 kcal mol(–1), near the physiological pH range (pH 6–8) and unfold via two partially folded intermediates, I(1) and I(2*), that are in equilibrium with the native and the unfolded state. Like the dimeric caspases, the monomeric coral caspases undergo a pH-dependent conformational change resulting from the titration of an evolutionarily conserved site. Data from molecular dynamics simulations paired with limited proteolysis and MALDI-TOF mass spectrometry show that the small subunit of the monomeric caspases is unstable and unfolds prior to the large subunit. Overall, the data suggest that all caspases share a conserved folding landscape, that a conserved allosteric site can be fine-tuned for species-specific regulation, and that the subfamily of stable dimers may have evolved to stabilize the small subunit. American Chemical Society 2023-05-31 /pmc/articles/PMC10286309/ /pubmed/37337671 http://dx.doi.org/10.1021/acs.biochem.3c00004 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by-nc-nd/4.0/Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Joglekar, Isha Clark, A. Clay Sequential Unfolding Mechanisms of Monomeric Caspases |
title | Sequential Unfolding
Mechanisms of Monomeric Caspases |
title_full | Sequential Unfolding
Mechanisms of Monomeric Caspases |
title_fullStr | Sequential Unfolding
Mechanisms of Monomeric Caspases |
title_full_unstemmed | Sequential Unfolding
Mechanisms of Monomeric Caspases |
title_short | Sequential Unfolding
Mechanisms of Monomeric Caspases |
title_sort | sequential unfolding
mechanisms of monomeric caspases |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10286309/ https://www.ncbi.nlm.nih.gov/pubmed/37337671 http://dx.doi.org/10.1021/acs.biochem.3c00004 |
work_keys_str_mv | AT joglekarisha sequentialunfoldingmechanismsofmonomericcaspases AT clarkaclay sequentialunfoldingmechanismsofmonomericcaspases |