HTRA1-Dependent Cell Cycle Proteomics
Jasmin Schillinger1, Katharina Severin1, Farnusch Kaschani1
1Centre of Medical Biotechnology, Faculty of Biology , University Duisburg-Essen, Universitaetsstrasse , 45141 Essen , Germany.
Abstract:
The HTRA1 gene encoding an evolutionary conserved protein quality-control factor can be epigenetically silenced or inactivated by mutation under pathologic conditions such as cancer. Recent evidence suggests that the loss of HTRA1 function causes multiple phenotypes, including the acceleration of cell growth, delayed onset of senescence, centrosome amplification, and polyploidy, suggesting an implication in the regulation of the cell cycle. To address this model, we performed a large-scale proteomics study to correlate the abundance of proteins and HTRA1 levels in various cell cycle phases using label-free-quantification mass spectrometry. These data indicate that the levels of 4723 proteins fluctuated in a cell-cycle-dependent manner, 2872 in a HTRA1-dependent manner, and 1530 in a cell-cycle- and HTRA1-dependent manner. The large number of proteins affected by the modulation of HTRA1 levels supports its general role in protein homeostasis. Moreover, the detected changes in protein abundance, in combination with pull-down data, implicate HTRA1 in various cell cycle events such as DNA replication, chromosome segregation, and cell-cycle-dependent apoptosis. These results highlight the wide implications of HTRA1 in cellular physiology.
Insights
The HTRA1 gene, a protein quality-control factor, influences cell cycle progression and protein homeostasis. Its modulation impacts numerous proteins, affecting DNA replication, chromosome segregation, and apoptosis.
Area of Science:
- Molecular Biology
- Proteomics
- Cell Biology
Background:
- The HTRA1 gene encodes a protein quality-control factor crucial for cellular function.
- HTRA1 dysfunction, via epigenetic silencing or mutation, is linked to pathologies like cancer and aberrant cell phenotypes.
- Loss of HTRA1 function is associated with accelerated cell growth, delayed senescence, centrosome amplification, and polyploidy, suggesting a role in cell cycle regulation.
Purpose of the Study:
- To investigate the role of HTRA1 in regulating protein abundance across different cell cycle phases.
- To correlate protein expression levels with HTRA1 abundance during the cell cycle using large-scale proteomics.
Main Methods:
- Utilized label-free-quantification mass spectrometry for a large-scale proteomics study.
- Correlated protein abundance with HTRA1 levels across various cell cycle phases.
- Employed pull-down assays to validate protein interactions and functional implications.
Main Results:
- Identified 4723 proteins with cell-cycle-dependent fluctuations.
- Found 2872 proteins affected by HTRA1 levels, with 1530 showing both cell-cycle and HTRA1 dependency.
- Demonstrated HTRA1's broad impact on protein homeostasis and its involvement in DNA replication, chromosome segregation, and apoptosis.
Conclusions:
- The extensive number of affected proteins underscores HTRA1's general role in maintaining protein homeostasis.
- HTRA1 significantly influences key cell cycle events, including DNA replication, chromosome segregation, and programmed cell death.
- These findings highlight the broad implications of HTRA1 in fundamental cellular physiology and disease processes.
