scholarly journals Regulation of mitochondrial dynamics by Aurora A kinase

2017 ◽  
Author(s):  
Rhys Grant ◽  
Ahmed Abdelbaki ◽  
Alessia Bertoldi ◽  
Maria P Gavilan ◽  
Jörg Mansfeld ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fraction ◽  
Mitochondrial Morphology ◽  
Aurora A Kinase ◽  
Mitochondrial Network ◽  
Aurora A ◽  
Mitochondrial Targeting ◽  
Cell Extracts ◽  
Different Levels

AbstractAurora A kinase (AURKA) is a major regulator of mitosis and an important driver of cancer progression. The roles of AURKA outside of mitosis, and how these might contribute to cancer progression, are not well understood. Here we show that a fraction of cytoplasmic AURKA is associated with mitochondria, co-fractionating in cell extracts and interacting with mitochondrial proteins by reciprocal co-immunoprecipitation. We have also found that the dynamics of the mitochondrial network are sensitive to AURKA inhibition, depletion or overexpression. This can account for the different mitochondrial morphologies observed in RPE1 and U2OS cell lines, which show very different levels of expression of AURKA. We identify the mitochondrial fraction of AURKA as influencing mitochondrial morphology, since an N-terminally truncated version of the kinase that does not localize to mitochondria does not affect the mitochondrial network. We identify a cryptic mitochondrial targeting sequence in the AURKA N-terminus and discuss how alternative conformations of the protein may influence its cytoplasmic fate.

scholarly journals Constitutive regulation of mitochondrial morphology by Aurora A kinase depends on a predicted cryptic targeting sequence at the N-terminus

Open Biology ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 170272 ◽  
Author(s):  
Rhys Grant ◽  
Ahmed Abdelbaki ◽  
Alessia Bertoldi ◽  
Maria P. Gavilan ◽  
Jörg Mansfeld ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Mitochondrial Fraction ◽  
Mitochondrial Morphology ◽  
Aurora A Kinase ◽  
Mitochondrial Network ◽  
Aurora A ◽  
Mitochondrial Targeting ◽  
Cell Extracts ◽  
N Terminus ◽  
Different Levels

Aurora A kinase (AURKA) is a major regulator of mitosis and an important driver of cancer progression. The roles of AURKA outside of mitosis, and how these might contribute to cancer progression, are not well understood. Here, we show that a fraction of cytoplasmic AURKA is associated with mitochondria, co-fractionating in cell extracts and interacting with mitochondrial proteins by reciprocal co-immunoprecipitation. We have also found that the dynamics of the mitochondrial network are sensitive to AURKA inhibition, depletion or overexpression. This can account for the different mitochondrial morphologies observed in RPE-1 and U2OS cell lines, which show very different levels of expression of AURKA. We identify the mitochondrial fraction of AURKA as influencing mitochondrial morphology, because an N-terminally truncated version of the kinase that does not localize to mitochondria does not affect the mitochondrial network. We identify a cryptic mitochondrial targeting sequence in the AURKA N-terminus and discuss how alternative conformations of the protein may influence its cytoplasmic fate.

scholarly journals Precise expression of Fis1 is important for glucose responsiveness of beta cells

2016 ◽  
Vol 230 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Julia Schultz ◽  
Rica Waterstradt ◽  
Tobias Kantowski ◽  
Annekatrin Rickmann ◽  
Florian Reinhardt ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Morphology ◽  
Mitochondrial Network ◽  
Primary Mouse ◽  
Glucose Stimulated Insulin Secretion ◽  
Glucose Responsiveness ◽  
Precise Expression

Mitochondrial network functionality is vital for glucose-stimulated insulin secretion in pancreatic beta cells. Altered mitochondrial dynamics in pancreatic beta cells are thought to trigger the development of type 2 diabetes mellitus. Fission protein 1 (Fis1) might be a key player in this process. Thus, the aim of this study was to investigate mitochondrial morphology in dependence of beta cell function, after knockdown and overexpression of Fis1. We demonstrate that glucose-unresponsive cells with impaired glucose-stimulated insulin secretion (INS1-832/2) showed decreased mitochondrial dynamics compared with glucose-responsive cells (INS1-832/13). Accordingly, mitochondrial morphology visualised using MitoTracker staining differed between the two cell lines. INS1-832/2 cells formed elongated and clustered mitochondria, whereas INS1-832/13 cells showed a homogenous mitochondrial network. Fis1 overexpression using lentiviral transduction significantly improved glucose-stimulated insulin secretion and mitochondrial network homogeneity in glucose-unresponsive cells. Conversely, Fis1 downregulation by shRNA, both in primary mouse beta cells and glucose-responsive INS1-832/13 cells, caused unresponsiveness and significantly greater numbers of elongated mitochondria. Overexpression of FIS1 in primary mouse beta cells indicated an upper limit at which higher FIS1 expression reduced glucose-stimulated insulin secretion. Thus, FIS1 was overexpressed stepwise up to a high concentration in RINm5F cells using the RheoSwitch system. Moderate FIS1 expression improved glucose-stimulated insulin secretion, whereas high expression resulted in loss of glucose responsiveness and in mitochondrial artificial loop structures and clustering. Our data confirm that FIS1 is a key regulator in pancreatic beta cells, because both glucose-stimulated insulin secretion and mitochondrial dynamics were clearly adapted to precise expression levels of this fission protein.

scholarly journals Human TPX2 is required for targeting Aurora-A kinase to the spindle

2002 ◽  
Vol 158 (4) ◽  
pp. 617-623 ◽  
Author(s):  
Thomas A. Kufer ◽  
Herman H.W. Silljé ◽  
Roman Körner ◽  
Oliver J. Gruss ◽  
Patrick Meraldi ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Major Protein ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Binding Studies ◽  
Serine Threonine Kinase ◽  
Cell Extracts ◽  
Prominent Component ◽  
Spindle Apparatus

Aurora-A is a serine-threonine kinase implicated in the assembly and maintenance of the mitotic spindle. Here we show that human Aurora-A binds to TPX2, a prominent component of the spindle apparatus. TPX2 was identified by mass spectrometry as a major protein coimmunoprecipitating specifically with Aurora-A from mitotic HeLa cell extracts. Conversely, Aurora-A could be detected in TPX2 immunoprecipitates. This indicates that subpopulations of these two proteins undergo complex formation in vivo. Binding studies demonstrated that the NH2 terminus of TPX2 can directly interact with the COOH-terminal catalytic domain of Aurora-A. Although kinase activity was not required for this interaction, TPX2 was readily phosphorylated by Aurora-A. Upon siRNA-mediated elimination of TPX2 from cells, the association of Aurora-A with the spindle microtubules was abolished, although its association with spindle poles was unaffected. Conversely, depletion of Aurora-A by siRNA had no detectable influence on the localization of TPX2. We propose that human TPX2 is required for targeting Aurora-A kinase to the spindle apparatus. In turn, Aurora-A might regulate the function of TPX2 during spindle assembly.

Aurora A kinase interacts with and phosphorylates VHL protein

Biologia ◽  
2012 ◽  
Vol 67 (5) ◽  
Author(s):  
Imen Ferchichi ◽  
Yannick Arlot ◽  
Jean-Yves Cremet ◽  
Claude Prigent ◽  
Amel Benammar Elgaaied
Keyword(s):  
Mitotic Spindle ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Hek 293 ◽  
Von Hippel Lindau ◽  
Cell Extracts ◽  
Vhl Protein ◽  
The Stability

AbstractThe serine/threonin kinase Aurora A is an oncoprotein, whereas von Hippel-Lindau protein (pVHL) is a tumor suppressor protein. Both proteins have the same localization during mitosis: in the mitotic spindle and the centrosome. These two proteins also have common functions, such as the regulation of the cell cycle, the stability of the mitotic spindle and both intervene in the functioning of centrosomes. In this study we have analyzed the interaction between Aurora A and pVHL with immunoprecipitation and in vitro phosphorylation experiments. We have confirmed that the immunoprecipitation of pVHL from Hek 293 cell extracts were coupled with Aurora A. In addition, the interaction between the two proteins has been tested by analyzing the phosphorylation of pVHL in vitro by Aurora A. The results revealed that pVHL was phosphorylated by Aurora A. In conclusion, the study demonstrated that Aurora A interacts with and phosphorylates pVHL. Given the role of these two proteins in cell division as well as their status in cancer, this interaction requires further investigation.

scholarly journals Ganglioside-induced differentiation associated protein 1 is a regulator of the mitochondrial network

2005 ◽  
Vol 170 (7) ◽  
pp. 1067-1078 ◽  
Author(s):  
Axel Niemann ◽  
Marcel Ruegg ◽  
Veronica La Padula ◽  
Angelo Schenone ◽  
Ueli Suter
Keyword(s):  
Mitochondrial Dynamics ◽  
Point Mutations ◽  
Mitochondrial Fusion ◽  
Proper Function ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Activity ◽  
Mitochondrial Morphology ◽  
Mitochondrial Network ◽  
Induced Differentiation ◽  
Mixed Features

Mutations in GDAP1 lead to severe forms of the peripheral motor and sensory neuropathy, Charcot-Marie-Tooth disease (CMT), which is characterized by heterogeneous phenotypes, including pronounced axonal damage and demyelination. We show that neurons and Schwann cells express ganglioside-induced differentiation associated protein 1 (GDAP1), which suggest that both cell types may contribute to the mixed features of the disease. GDAP1 is located in the mitochondrial outer membrane and regulates the mitochondrial network. Overexpression of GDAP1 induces fragmentation of mitochondria without inducing apoptosis, affecting overall mitochondrial activity, or interfering with mitochondrial fusion. The mitochondrial fusion proteins, mitofusin 1 and 2 and Drp1(K38A), can counterbalance the GDAP1-dependent fission. GDAP1-specific knockdown by RNA interference results in a tubular mitochondrial morphology. GDAP1 truncations that are found in patients who have CMT are not targeted to mitochondria and have lost mitochondrial fragmentation activity. The latter activity also is reduced strongly for disease-associated GDAP1 point mutations. Our data indicate that an exquisitely tight control of mitochondrial dynamics, regulated by GDAP1, is crucial for the proper function of myelinated peripheral nerves.

Suppression of multiple processes relevant to cancer progression by benzyl isothiocyanate may result from the inhibition of Aurora A kinase activity

2020 ◽  
Vol 11 (10) ◽  
pp. 9010-9019
Author(s):  
Tzu-Tung Yu ◽  
Meng-Ya Chang ◽  
Yi-Jen Hsieh ◽  
Chih-Jui Chang
Keyword(s):  
Cancer Progression ◽  
Kinase Activity ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Benzyl Isothiocyanate ◽  
Anti Cancer ◽  
Multiple Processes

The anti-cancer properties of BITC may result from the inhibition of Aurora A kinase activity.

scholarly journals An analysis of respiratory function and mitochondrial morphology in Candida albicans

2019 ◽  
Author(s):  
Lucian Duvenage ◽  
Daniel R. Pentland ◽  
Carol A. Munro ◽  
Campbell W. Gourlay
Keyword(s):  
Candida Albicans ◽  
Respiratory Function ◽  
Fungal Pathogens ◽  
Mitochondrial Dynamics ◽  
Cell Types ◽  
Mitochondrial Activity ◽  
Mitochondrial Morphology ◽  
Mitochondrial Network ◽  
Response To Stress ◽  
And Oxidative Stress

AbstractRespiratory function and mitochondrial dynamics have been well characterised in a number of cell types, including the model yeast Saccharomyces cerevisiae, but remain under-researched in fungal pathogens such as Candida albicans. An understanding of mitochondrial activity and morphology is important if we are to understand the role that this organelle plays in adaption and response to stress. Here we examine the respiratory profiles of several prominent pathogenic Candida species and present a useful GFP probe for the study of mitochondrial morphology. We examine mitochondrial morphology under a variety of conditions that Candida species may encounter within the host, such as acidic pH, respiratory and oxidative stress. The GFP probe also allowed for the visualisation of mitochondria during hyphal development, during growth following macrophage engulfment and distribution within biofilms. These data demonstrate that the mitochondrial network of C. albicans is highly responsive to both environmental conditions and developmental cues, suggesting important roles for this organelle in environmental adaption.

scholarly journals Mitochondrial dynamics and cancer

Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769839 ◽  
Author(s):  
Paola Maycotte ◽  
Alvaro Marín-Hernández ◽  
Miriam Goyri-Aguirre ◽  
Maricruz Anaya-Ruiz ◽  
Julio Reyes-Leyva ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Inflammatory Diseases ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Activity ◽  
Mitochondrial Morphology ◽  
Special Focus ◽  
Diagnostic Strategies ◽  
Recent Advances ◽  
The Many ◽  
External Stimuli

Cancer is among the leading causes of death worldwide, and the number of new cases continues to rise. Despite recent advances in diagnosis and therapeutic strategies, millions of cancer-related deaths occur, indicating the need for better therapies and diagnostic strategies. Mitochondria and metabolic alterations have been recognized as important for cancer progression. However, a more precise understanding of how to manipulate mitochondria-related processes for cancer therapy remains to be established. Mitochondria are highly dynamic organelles which continually fuse and divide in response to diverse stimuli. Participation in the aforementioned processes requires a precise regulation at many levels that allows the cell to couple mitochondrial activity to nutrient availability, biosynthetic demands, proliferation rates, and external stimuli. The many functions of these organelles are intimately linked to their morphology. Recent evidence suggests an important link between mitochondrial morphology and disease, including neurodegenerative, inflammatory diseases and cancer. Here, we review recent advances in the understanding of mitochondrial dynamics with a special focus on its relationship to tumor progression.

scholarly journals Mitochondrial fission regulates germ cell differentiation by suppressing ROS-mediated activation of Epidermal Growth Factor Signaling in the Drosophila larval testis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rafael Sênos Demarco ◽  
D. Leanne Jones
Keyword(s):  
Cell Differentiation ◽  
Germ Cell ◽  
Germ Cells ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Germline Stem Cell ◽  
Mitochondrial Morphology ◽  
Mitochondrial Network ◽  
Germ Cell Differentiation

AbstractMitochondria are essential organelles that have recently emerged as hubs for several metabolic and signaling pathways in the cell. Mitochondrial morphology is regulated by constant fusion and fission events to maintain a functional mitochondrial network and to remodel the mitochondrial network in response to external stimuli. Although the role of mitochondria in later stages of spermatogenesis has been investigated in depth, the role of mitochondrial dynamics in regulating early germ cell behavior is relatively less-well understood. We previously demonstrated that mitochondrial fusion is required for germline stem cell (GSC) maintenance in the Drosophila testis. Here, we show that mitochondrial fission is also important for regulating the maintenance of early germ cells in larval testes. Inhibition of Drp1 in early germ cells resulted in the loss of GSCs and spermatogonia due to the accumulation of reactive oxygen species (ROS) and activation of the EGFR pathway in adjacent somatic cyst cells. EGFR activation contributed to premature germ cell differentiation. Our data provide insights into how mitochondrial dynamics can impact germ cell maintenance and differentiation via distinct mechanisms throughout development.

scholarly journals Aurora-A mediated phosphorylation of LDHB promotes glycolysis and tumor progression by relieving the substrate-inhibition effect

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Aoxing Cheng ◽  
Peng Zhang ◽  
Bo Wang ◽  
Dongdong Yang ◽  
Xiaotao Duan ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cancer Progression ◽  
Substrate Inhibition ◽  
Lactate Production ◽  
Metabolic Reprogramming ◽  
Glycolytic Flux ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Inhibition Effect ◽  
A Subunit

AbstractOverexpressed Aurora-A kinase promotes tumor growth through various pathways, but whether Aurora-A is also involved in metabolic reprogramming-mediated cancer progression remains unknown. Here, we report that Aurora-A directly interacts with and phosphorylates lactate dehydrogenase B (LDHB), a subunit of the tetrameric enzyme LDH that catalyzes the interconversion between pyruvate and lactate. Aurora-A-mediated phosphorylation of LDHB serine 162 significantly increases its activity in reducing pyruvate to lactate, which efficiently promotes NAD+ regeneration, glycolytic flux, lactate production and bio-synthesis with glycolytic intermediates. Mechanistically, LDHB serine 162 phosphorylation relieves its substrate inhibition effect by pyruvate, resulting in remarkable elevation in the conversions of pyruvate and NADH to lactate and NAD+. Blocking S162 phosphorylation by expression of a LDHB-S162A mutant inhibited glycolysis and tumor growth in cancer cells and xenograft models. This study uncovers a function of Aurora-A in glycolytic modulation and a mechanism through which LDHB directly contributes to the Warburg effect.

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