Dataset Information

Identification of tubulins as substrates of serine protease HtrA1 by mixture-based oriented peptide library screening.

ABSTRACT: Serine protease HtrA1 belongs to a family of chymotrypsin-like proteases that were first identified in bacteria and later in mammalian systems. These proteases were identified as components of protein quality control in prokaryotic systems and as regulators of diverse signaling pathways in mammalian systems. In particular, HtrA1 is implicated in trophoblast cell migration and invasion, tumor progression, chemotherapy-induced cytotoxicity, osteoarthritis, age-related macular degeneration, and pathogenesis of Alzheimer's disease. However, systematic analysis of its potential substrates in biological system is still lacking. Therefore, we performed a mixture-based oriented peptide library screening to identify putative substrates of HtrA1. We identified [AEGR]-[LAGR]-[IAMLR]-[TVIAL] as consensus residues for P1 to P4 sites. We identified several putative substrates of HtrA1 involved in the pathogenesis of various diseases. In this study, we report on the identification of tubulins as potential substrates of HtrA1, and validated tubulins as in vitro and intracellular substrates of HtrA1. These results provide initial insights into substrate identification and functional characterization of HtrA1 in pathogenesis of various diseases.

SUBMITTER: Chien J

PROVIDER: S-EPMC2983094 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Identification of tubulins as substrates of serine protease HtrA1 by mixture-based oriented peptide library screening.

Chien Jeremy J He Xiaoping X Shridhar Viji V

Journal of cellular biochemistry 20090501 2

Serine protease HtrA1 belongs to a family of chymotrypsin-like proteases that were first identified in bacteria and later in mammalian systems. These proteases were identified as components of protein quality control in prokaryotic systems and as regulators of diverse signaling pathways in mammalian systems. In particular, HtrA1 is implicated in trophoblast cell migration and invasion, tumor progression, chemotherapy-induced cytotoxicity, osteoarthritis, age-related macular degeneration, and pat ...[more]

PMID: 19301262

Similar Datasets

Project description:HTRA1 is a highly conserved serine protease which has been implicated in suppression of epithelial-to-mesenchymal-transition (EMT) and cell motility in breast cancer. Its prognostic relevance for breast cancer is unclear so far. Therefore, we evaluated the impact of HTRA1 mRNA expression on patient outcome using a cohort of 131 breast cancer patients as well as a validation cohort including 2809 publically available data sets. Additionally, we aimed at investigating for the presence of promoter hypermethylation as a mechanism for silencing the HTRA1 gene in breast tumors. HTRA1 downregulation was detected in more than 50% of the breast cancer specimens and was associated with higher tumor stage (p?=?0.025). By applying Cox proportional hazard models, we observed favorable overall (OS) and disease-free survival (DFS) related to high HTRA1 expression (HR?=?0.45 [CI 0.23-0.90], p?=?0.023; HR?=?0.55 [CI 0.32-0.94], p?=?0.028, respectively), with even more pronounced impact in node-positive patients (HR?=?0.21 [CI 0.07-0.63], p?=?0.006; HR?=?0.29 [CI 0.13-0.65], p?=?0.002, respectively). Moreover, HTRA1 remained a statistically significant factor predicting DFS among established clinical parameters in the multivariable analysis. Its impact on patient outcome was independently confirmed in the validation set (for relapse-free survival (n?=?2809): HR?=?0.79 [CI 0.7-0.9], log-rank p?=?0.0003; for OS (n?=?971): HR?=?0.63 [CI 0.48-0.83], log-rank p?=?0.0009). In promoter analyses, we in fact detected methylation of HTRA1 in a small subset of breast cancer specimens (two out of a series of 12), and in MCF-7 breast cancer cells which exhibited 22-fold lower HTRA1 mRNA expression levels compared to unmethylated MDA-MB-231 cells. In conclusion, we show that downregulation of HTRA1 is associated with shorter patient survival, particularly in node-positive breast cancer. Since HTRA1 loss was demonstrated to induce EMT and cancer cell invasion, these patients might benefit from demethylating agents or histone deacetylase inhibitors previously reported to lead to HTRA1 upregulation, or from novel small-molecule inhibitors targeting EMT-related processes.

Dataset Information

Identification of tubulins as substrates of serine protease HtrA1 by mixture-based oriented peptide library screening.

Publications

Identification of tubulins as substrates of serine protease HtrA1 by mixture-based oriented peptide library screening.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets