Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.

High temperature requirement protein A1 (HtrA1), a secreted serine protease of the HtrA family, is associated with a multitude of human diseases. However, the exact functions of HtrA1 in these diseases remain poorly understood. We seek to unravel the mechanisms of HtrA1 by elucidating its interactio...

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Main Authors: Hakryul Jo, Victoria Patterson, Sean Stoessel, Chia-Yi Kuan, Josephine Hoh
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4266670?pdf=render
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author Hakryul Jo
Victoria Patterson
Sean Stoessel
Chia-Yi Kuan
Josephine Hoh
author_facet Hakryul Jo
Victoria Patterson
Sean Stoessel
Chia-Yi Kuan
Josephine Hoh
author_sort Hakryul Jo
collection DOAJ
description High temperature requirement protein A1 (HtrA1), a secreted serine protease of the HtrA family, is associated with a multitude of human diseases. However, the exact functions of HtrA1 in these diseases remain poorly understood. We seek to unravel the mechanisms of HtrA1 by elucidating its interactions with chemical or biological modulators. To this end, we screened a small molecule library of 500 bioactive compounds to identify those that alter the formation of extracellular HtrA1 complexes in the cell culture medium. An initial characterization of two novel hits from this screen showed that protoporphyrin IX (PPP-IX), a precursor in the heme biosynthetic pathway, and its metalloporphyrin (MPP) derivatives fostered the oligomerization of HtrA1 by binding to the protease domain. As a result of the interaction with MPPs, the proteolytic activity of HtrA1 against Fibulin-5, a specific HtrA1 substrate in age-related macular degeneration (AMD), was increased. This physical interaction could be abolished by the missense mutations of HtrA1 found in patients with cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). Furthermore, knockdown of HtrA1 attenuated apoptosis induced by PPP-IX. These results suggest that PPP-IX, or its derivatives, and HtrA1 may function as co-factors whereby porphyrins enhance oligomerization and the protease activity of HtrA1, while active HtrA1 elevates the pro-apoptotic actions of porphyrin derivatives. Further analysis of this interplay may shed insights into the pathogenesis of diseases such as AMD, CARASIL and protoporphyria, as well as effective therapeutic development.
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spelling doaj.art-c475692fbdf04028b17720341df5596f2022-12-22T01:42:48ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-01912e11536210.1371/journal.pone.0115362Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.Hakryul JoVictoria PattersonSean StoesselChia-Yi KuanJosephine HohHigh temperature requirement protein A1 (HtrA1), a secreted serine protease of the HtrA family, is associated with a multitude of human diseases. However, the exact functions of HtrA1 in these diseases remain poorly understood. We seek to unravel the mechanisms of HtrA1 by elucidating its interactions with chemical or biological modulators. To this end, we screened a small molecule library of 500 bioactive compounds to identify those that alter the formation of extracellular HtrA1 complexes in the cell culture medium. An initial characterization of two novel hits from this screen showed that protoporphyrin IX (PPP-IX), a precursor in the heme biosynthetic pathway, and its metalloporphyrin (MPP) derivatives fostered the oligomerization of HtrA1 by binding to the protease domain. As a result of the interaction with MPPs, the proteolytic activity of HtrA1 against Fibulin-5, a specific HtrA1 substrate in age-related macular degeneration (AMD), was increased. This physical interaction could be abolished by the missense mutations of HtrA1 found in patients with cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). Furthermore, knockdown of HtrA1 attenuated apoptosis induced by PPP-IX. These results suggest that PPP-IX, or its derivatives, and HtrA1 may function as co-factors whereby porphyrins enhance oligomerization and the protease activity of HtrA1, while active HtrA1 elevates the pro-apoptotic actions of porphyrin derivatives. Further analysis of this interplay may shed insights into the pathogenesis of diseases such as AMD, CARASIL and protoporphyria, as well as effective therapeutic development.http://europepmc.org/articles/PMC4266670?pdf=render
spellingShingle Hakryul Jo
Victoria Patterson
Sean Stoessel
Chia-Yi Kuan
Josephine Hoh
Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.
PLoS ONE
title Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.
title_full Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.
title_fullStr Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.
title_full_unstemmed Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.
title_short Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease.
title_sort protoporphyrins enhance oligomerization and enzymatic activity of htra1 serine protease
url http://europepmc.org/articles/PMC4266670?pdf=render
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