13 research outputs found
Spatial Distribution of Cellular Function: The Partitioning of Proteins between Mitochondria and the Nucleus in MCF7 Breast Cancer Cells
Concurrent proteomics analysis of the nuclei and mitochondria
of MCF7 breast cancer cells identified 985 proteins (40% of all detected
proteins) present in both organelles. Numerous proteins from all five
complexes involved in oxidative phosphorylation (e.g., NDUFA5, NDUFB10,
NDUFS1, NDUF2, SDHA, UQRB, UQRC2, UQCRH, COX5A, COX5B, MT-CO2, ATP5A1,
ATP5B, ATP5H, etc.), from the TCA-cycle (DLST, IDH2, IDH3A, OGDH,
SUCLAG2, etc.), and from glycolysis (ALDOA, ENO1, FBP1, GPI, PGK1,
TALDO1, etc.) were distributed to both the nucleus and mitochondria.
In contrast, proteins involved in nuclear/mitochondrial RNA processing/translation
and Ras/Rab signaling showed different partitioning patterns. The
identity of the OxPhos, TCA-cycle, and glycolysis proteins distributed
to both the nucleus and mitochondria provides evidence for spatio-functional
integration of these processes over the two different subcellular
organelles. We suggest that there are unrecognized aspects of functional
coordination between the nucleus and mitochondria, that integration
of core functional processes via wide subcellular distribution of
constituent proteins is a common characteristic of cells, and that subcellular spatial integration of function may be a vital aspect of cancer
Spatial Distribution of Cellular Function: The Partitioning of Proteins between Mitochondria and the Nucleus in MCF7 Breast Cancer Cells
Concurrent proteomics analysis of the nuclei and mitochondria
of MCF7 breast cancer cells identified 985 proteins (40% of all detected
proteins) present in both organelles. Numerous proteins from all five
complexes involved in oxidative phosphorylation (e.g., NDUFA5, NDUFB10,
NDUFS1, NDUF2, SDHA, UQRB, UQRC2, UQCRH, COX5A, COX5B, MT-CO2, ATP5A1,
ATP5B, ATP5H, etc.), from the TCA-cycle (DLST, IDH2, IDH3A, OGDH,
SUCLAG2, etc.), and from glycolysis (ALDOA, ENO1, FBP1, GPI, PGK1,
TALDO1, etc.) were distributed to both the nucleus and mitochondria.
In contrast, proteins involved in nuclear/mitochondrial RNA processing/translation
and Ras/Rab signaling showed different partitioning patterns. The
identity of the OxPhos, TCA-cycle, and glycolysis proteins distributed
to both the nucleus and mitochondria provides evidence for spatio-functional
integration of these processes over the two different subcellular
organelles. We suggest that there are unrecognized aspects of functional
coordination between the nucleus and mitochondria, that integration
of core functional processes via wide subcellular distribution of
constituent proteins is a common characteristic of cells, and that subcellular spatial integration of function may be a vital aspect of cancer
Spatial Distribution of Cellular Function: The Partitioning of Proteins between Mitochondria and the Nucleus in MCF7 Breast Cancer Cells
Concurrent proteomics analysis of the nuclei and mitochondria
of MCF7 breast cancer cells identified 985 proteins (40% of all detected
proteins) present in both organelles. Numerous proteins from all five
complexes involved in oxidative phosphorylation (e.g., NDUFA5, NDUFB10,
NDUFS1, NDUF2, SDHA, UQRB, UQRC2, UQCRH, COX5A, COX5B, MT-CO2, ATP5A1,
ATP5B, ATP5H, etc.), from the TCA-cycle (DLST, IDH2, IDH3A, OGDH,
SUCLAG2, etc.), and from glycolysis (ALDOA, ENO1, FBP1, GPI, PGK1,
TALDO1, etc.) were distributed to both the nucleus and mitochondria.
In contrast, proteins involved in nuclear/mitochondrial RNA processing/translation
and Ras/Rab signaling showed different partitioning patterns. The
identity of the OxPhos, TCA-cycle, and glycolysis proteins distributed
to both the nucleus and mitochondria provides evidence for spatio-functional
integration of these processes over the two different subcellular
organelles. We suggest that there are unrecognized aspects of functional
coordination between the nucleus and mitochondria, that integration
of core functional processes via wide subcellular distribution of
constituent proteins is a common characteristic of cells, and that subcellular spatial integration of function may be a vital aspect of cancer
Spatial Distribution of Cellular Function: The Partitioning of Proteins between Mitochondria and the Nucleus in MCF7 Breast Cancer Cells
Concurrent proteomics analysis of the nuclei and mitochondria
of MCF7 breast cancer cells identified 985 proteins (40% of all detected
proteins) present in both organelles. Numerous proteins from all five
complexes involved in oxidative phosphorylation (e.g., NDUFA5, NDUFB10,
NDUFS1, NDUF2, SDHA, UQRB, UQRC2, UQCRH, COX5A, COX5B, MT-CO2, ATP5A1,
ATP5B, ATP5H, etc.), from the TCA-cycle (DLST, IDH2, IDH3A, OGDH,
SUCLAG2, etc.), and from glycolysis (ALDOA, ENO1, FBP1, GPI, PGK1,
TALDO1, etc.) were distributed to both the nucleus and mitochondria.
In contrast, proteins involved in nuclear/mitochondrial RNA processing/translation
and Ras/Rab signaling showed different partitioning patterns. The
identity of the OxPhos, TCA-cycle, and glycolysis proteins distributed
to both the nucleus and mitochondria provides evidence for spatio-functional
integration of these processes over the two different subcellular
organelles. We suggest that there are unrecognized aspects of functional
coordination between the nucleus and mitochondria, that integration
of core functional processes via wide subcellular distribution of
constituent proteins is a common characteristic of cells, and that subcellular spatial integration of function may be a vital aspect of cancer
Spatial Distribution of Cellular Function: The Partitioning of Proteins between Mitochondria and the Nucleus in MCF7 Breast Cancer Cells
Concurrent proteomics analysis of the nuclei and mitochondria
of MCF7 breast cancer cells identified 985 proteins (40% of all detected
proteins) present in both organelles. Numerous proteins from all five
complexes involved in oxidative phosphorylation (e.g., NDUFA5, NDUFB10,
NDUFS1, NDUF2, SDHA, UQRB, UQRC2, UQCRH, COX5A, COX5B, MT-CO2, ATP5A1,
ATP5B, ATP5H, etc.), from the TCA-cycle (DLST, IDH2, IDH3A, OGDH,
SUCLAG2, etc.), and from glycolysis (ALDOA, ENO1, FBP1, GPI, PGK1,
TALDO1, etc.) were distributed to both the nucleus and mitochondria.
In contrast, proteins involved in nuclear/mitochondrial RNA processing/translation
and Ras/Rab signaling showed different partitioning patterns. The
identity of the OxPhos, TCA-cycle, and glycolysis proteins distributed
to both the nucleus and mitochondria provides evidence for spatio-functional
integration of these processes over the two different subcellular
organelles. We suggest that there are unrecognized aspects of functional
coordination between the nucleus and mitochondria, that integration
of core functional processes via wide subcellular distribution of
constituent proteins is a common characteristic of cells, and that subcellular spatial integration of function may be a vital aspect of cancer
Nuclear Cytoplasmic Trafficking of Proteins is a Major Response of Human Fibroblasts to Oxidative Stress
We have used a subcellular spatial
razor approach based on LC–MS/MS-based
proteomics with SILAC isotope labeling to determine changes in protein
abundances in the nuclear and cytoplasmic compartments of human IMR90
fibroblasts subjected to mild oxidative stress. We show that response
to mild <i>tert</i>-butyl hydrogen peroxide treatment includes
redistribution between the nucleus and cytoplasm of numerous proteins
not previously associated with oxidative stress. The 121 proteins
with the most significant changes encompass proteins with known functions
in a wide variety of subcellular locations and of cellular functional
processes (transcription, signal transduction, autophagy, iron metabolism,
TCA cycle, ATP synthesis) and are consistent with functional networks
that are spatially dispersed across the cell. Both nuclear respiratory
factor 2 and the proline regulatory axis appear to contribute to the
cellular metabolic response. Proteins involved in iron metabolism
or with iron/heme as a cofactor as well as mitochondrial proteins
are prominent in the response. Evidence suggesting that nuclear import/export
and vesicle-mediated protein transport contribute to the cellular
response was obtained. We suggest that measurements of global changes
in total cellular protein abundances need to be complemented with
measurements of the dynamic subcellular spatial redistribution of
proteins to obtain comprehensive pictures of cellular function
Subcellular Proteomics Reveals a Role for Nucleo-cytoplasmic Trafficking at the DNA Replication Origin Activation Checkpoint
Depletion of DNA replication initiation factors such
as CDC7 kinase triggers the origin activation checkpoint in healthy
cells and leads to a protective cell cycle arrest at the G1 phase
of the mitotic cell division cycle. This protective mechanism is thought
to be defective in cancer cells. To investigate how this checkpoint
is activated and maintained in healthy cells, we conducted a quantitative
SILAC analysis of the nuclear- and cytoplasmic-enriched compartments
of CDC7-depleted fibroblasts and compared them to a total cell lysate
preparation. Substantial changes in total abundance and/or subcellular
location were detected for 124 proteins, including many essential
proteins associated with DNA replication/cell cycle. Similar changes
in protein abundance and subcellular distribution were observed for
various metabolic processes, including oxidative stress, iron metabolism,
protein translation and the tricarboxylic acid cycle. This is accompanied
by reduced abundance of two karyopherin proteins, suggestive of reduced
nuclear import. We propose that altered nucleo-cytoplasmic trafficking
plays a key role in the regulation of cell cycle arrest. The results
increase understanding of the mechanisms underlying maintenance of
the DNA replication origin activation checkpoint and are consistent
with our proposal that cell cycle arrest is an actively maintained
process that appears to be distributed over various subcellular locations
Subcellular Proteomics Reveals a Role for Nucleo-cytoplasmic Trafficking at the DNA Replication Origin Activation Checkpoint
Depletion of DNA replication initiation factors such
as CDC7 kinase triggers the origin activation checkpoint in healthy
cells and leads to a protective cell cycle arrest at the G1 phase
of the mitotic cell division cycle. This protective mechanism is thought
to be defective in cancer cells. To investigate how this checkpoint
is activated and maintained in healthy cells, we conducted a quantitative
SILAC analysis of the nuclear- and cytoplasmic-enriched compartments
of CDC7-depleted fibroblasts and compared them to a total cell lysate
preparation. Substantial changes in total abundance and/or subcellular
location were detected for 124 proteins, including many essential
proteins associated with DNA replication/cell cycle. Similar changes
in protein abundance and subcellular distribution were observed for
various metabolic processes, including oxidative stress, iron metabolism,
protein translation and the tricarboxylic acid cycle. This is accompanied
by reduced abundance of two karyopherin proteins, suggestive of reduced
nuclear import. We propose that altered nucleo-cytoplasmic trafficking
plays a key role in the regulation of cell cycle arrest. The results
increase understanding of the mechanisms underlying maintenance of
the DNA replication origin activation checkpoint and are consistent
with our proposal that cell cycle arrest is an actively maintained
process that appears to be distributed over various subcellular locations
Subcellular Proteomics Reveals a Role for Nucleo-cytoplasmic Trafficking at the DNA Replication Origin Activation Checkpoint
Depletion of DNA replication initiation factors such
as CDC7 kinase triggers the origin activation checkpoint in healthy
cells and leads to a protective cell cycle arrest at the G1 phase
of the mitotic cell division cycle. This protective mechanism is thought
to be defective in cancer cells. To investigate how this checkpoint
is activated and maintained in healthy cells, we conducted a quantitative
SILAC analysis of the nuclear- and cytoplasmic-enriched compartments
of CDC7-depleted fibroblasts and compared them to a total cell lysate
preparation. Substantial changes in total abundance and/or subcellular
location were detected for 124 proteins, including many essential
proteins associated with DNA replication/cell cycle. Similar changes
in protein abundance and subcellular distribution were observed for
various metabolic processes, including oxidative stress, iron metabolism,
protein translation and the tricarboxylic acid cycle. This is accompanied
by reduced abundance of two karyopherin proteins, suggestive of reduced
nuclear import. We propose that altered nucleo-cytoplasmic trafficking
plays a key role in the regulation of cell cycle arrest. The results
increase understanding of the mechanisms underlying maintenance of
the DNA replication origin activation checkpoint and are consistent
with our proposal that cell cycle arrest is an actively maintained
process that appears to be distributed over various subcellular locations
Subcellular Proteomics Reveals a Role for Nucleo-cytoplasmic Trafficking at the DNA Replication Origin Activation Checkpoint
Depletion of DNA replication initiation factors such
as CDC7 kinase triggers the origin activation checkpoint in healthy
cells and leads to a protective cell cycle arrest at the G1 phase
of the mitotic cell division cycle. This protective mechanism is thought
to be defective in cancer cells. To investigate how this checkpoint
is activated and maintained in healthy cells, we conducted a quantitative
SILAC analysis of the nuclear- and cytoplasmic-enriched compartments
of CDC7-depleted fibroblasts and compared them to a total cell lysate
preparation. Substantial changes in total abundance and/or subcellular
location were detected for 124 proteins, including many essential
proteins associated with DNA replication/cell cycle. Similar changes
in protein abundance and subcellular distribution were observed for
various metabolic processes, including oxidative stress, iron metabolism,
protein translation and the tricarboxylic acid cycle. This is accompanied
by reduced abundance of two karyopherin proteins, suggestive of reduced
nuclear import. We propose that altered nucleo-cytoplasmic trafficking
plays a key role in the regulation of cell cycle arrest. The results
increase understanding of the mechanisms underlying maintenance of
the DNA replication origin activation checkpoint and are consistent
with our proposal that cell cycle arrest is an actively maintained
process that appears to be distributed over various subcellular locations