scholarly journals 14‐3‐3γ prevents centrosome duplication by inhibiting NPM1 function

2021 ◽  
Author(s):  
Arunabha Bose ◽  
Kruti Modi ◽  
Suchismita Dey ◽  
Somavally Dalvi ◽  
Prafful Nadkarni ◽  
...  
Keyword(s):  
Centrosome Duplication

scholarly journals Loss of the Conserved Alveolate Kinase MAPK2 Decouples Toxoplasma Cell Growth from Cell Division

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
Author(s):  
Xiaoyu Hu ◽  
William J. O’Shaughnessy ◽  
Tsebaot G. Beraki ◽  
Michael L. Reese
Keyword(s):  
Toxoplasma Gondii ◽  
Protein Kinases ◽  
Daughter Cell ◽  
Protozoan Parasite ◽  
Productive Infection ◽  
Centrosome Duplication ◽  
Loss Of Function ◽  
Content Type ◽  
Mitogen Activated Protein ◽  
Parasite Replication

ABSTRACT Mitogen-activated protein kinases (MAPKs) are a conserved family of protein kinases that regulate signal transduction, proliferation, and development throughout eukaryotes. The apicomplexan parasite Toxoplasma gondii expresses three MAPKs. Two of these, extracellular signal-regulated kinase 7 (ERK7) and MAPKL1, have been implicated in the regulation of conoid biogenesis and centrosome duplication, respectively. The third kinase, MAPK2, is specific to and conserved throughout the Alveolata, although its function is unknown. We used the auxin-inducible degron system to determine phenotypes associated with MAPK2 loss of function in Toxoplasma. We observed that parasites lacking MAPK2 failed to duplicate their centrosomes and therefore did not initiate daughter cell budding, which ultimately led to parasite death. MAPK2-deficient parasites initiated but did not complete DNA replication and arrested prior to mitosis. Surprisingly, the parasites continued to grow and replicate their Golgi apparatus, mitochondria, and apicoplasts. We found that the failure in centrosome duplication is distinct from the phenotype caused by the depletion of MAPKL1. As we did not observe MAPK2 localization at the centrosome at any point in the cell cycle, our data suggest that MAPK2 regulates a process at a distal site that is required for the completion of centrosome duplication and the initiation of parasite mitosis. IMPORTANCE Toxoplasma gondii is a ubiquitous intracellular protozoan parasite that can cause severe and fatal disease in immunocompromised patients and the developing fetus. Rapid parasite replication is critical for establishing a productive infection. Here, we demonstrate that a Toxoplasma protein kinase called MAPK2 is conserved throughout the Alveolata and essential for parasite replication. We found that parasites lacking MAPK2 protein were defective in the initiation of daughter cell budding and were rendered inviable. Specifically, T. gondii MAPK2 (TgMAPK2) appears to be required for centrosome replication at the basal end of the nucleus, and its loss causes arrest early in parasite division. MAPK2 is unique to the Alveolata and not found in metazoa and likely is a critical component of an essential parasite-specific signaling network.

scholarly journals Key phosphorylation events in Spc29 and Spc42 guide multiple steps of yeast centrosome duplication

2018 ◽  
Vol 29 (19) ◽  
pp. 2280-2291 ◽  
Author(s):  
Michele Haltiner Jones ◽  
Eileen T. O’Toole ◽  
Amy S. Fabritius ◽  
Eric G. Muller ◽  
Janet B. Meehl ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Centrosome Duplication ◽  
Phosphorylation Sites ◽  
Cycle Progression ◽  
Cellular Processes ◽  
Pole Body ◽  
Core Components ◽  
Spindle Elongation

Phosphorylation modulates many cellular processes during cell cycle progression. The yeast centrosome (called the spindle pole body, SPB) is regulated by the protein kinases Mps1 and Cdc28/Cdk1 as it nucleates microtubules to separate chromosomes during mitosis. Previously we completed an SPB phosphoproteome, identifying 297 sites on 17 of the 18 SPB components. Here we describe mutagenic analysis of phosphorylation events on Spc29 and Spc42, two SPB core components that were shown in the phosphoproteome to be heavily phosphorylated. Mutagenesis at multiple sites in Spc29 and Spc42 suggests that much of the phosphorylation on these two proteins is not essential but enhances several steps of mitosis. Of the 65 sites examined on both proteins, phosphorylation of the Mps1 sites Spc29-T18 and Spc29-T240 was shown to be critical for function. Interestingly, these two sites primarily influence distinct successive steps; Spc29-T240 is important for the interaction of Spc29 with Spc42, likely during satellite formation, and Spc29-T18 facilitates insertion of the new SPB into the nuclear envelope and promotes anaphase spindle elongation. Phosphorylation sites within Cdk1 motifs affect function to varying degrees, but mutations only have significant effects in the presence of an MPS1 mutation, supporting a theme of coregulation by these two kinases.

scholarly journals Phosphorylation of Centrin during the Cell Cycle and Its Role in Centriole Separation Preceding Centrosome Duplication

2001 ◽  
Vol 276 (23) ◽  
pp. 20774-20780 ◽  
Author(s):  
Ward Lutz ◽  
Wilma L. Lingle ◽  
Daniel McCormick ◽  
Tammy M. Greenwood ◽  
Jeffrey L. Salisbury
Keyword(s):  
Cell Cycle ◽  
Centrosome Duplication

scholarly journals Stat3 Activity Is Required for Centrosome Duplication in Chinese Hamster Ovary Cells

2004 ◽  
Vol 279 (40) ◽  
pp. 41801-41806 ◽  
Author(s):  
Brandon Metge ◽  
Solomon Ofori-Acquah ◽  
Troy Stevens ◽  
Ron Balczon
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Centrosome Duplication ◽  
Ovary Cells

scholarly journals The SCF ubiquitin ligase protein Slimb regulates centrosome duplication in Drosophila

2000 ◽  
Vol 10 (18) ◽  
pp. 1131-1134 ◽  
Author(s):  
Edward J. Wojcik ◽  
David M. Glover ◽  
Thomas S. Hays
Keyword(s):  
Ubiquitin Ligase ◽  
Centrosome Duplication ◽  
Scf Ubiquitin Ligase

scholarly journals Mortalin controls centrosome duplication via modulating centrosomal localization of p53

Oncogene ◽  
2006 ◽  
Vol 25 (39) ◽  
pp. 5377-5390 ◽  
Author(s):  
Z Ma ◽  
H Izumi ◽  
M Kanai ◽  
Y Kabuyama ◽  
N G Ahn ◽  
...  
Keyword(s):  
Centrosome Duplication

scholarly journals Specific Phosphorylation of Nucleophosmin on Thr199by Cyclin- dependent Kinase 2-Cyclin E and Its Role in Centrosome Duplication

2001 ◽  
Vol 276 (24) ◽  
pp. 21529-21537 ◽  
Author(s):  
Yukari Tokuyama ◽  
Henning F. Horn ◽  
Kenji Kawamura ◽  
Pheruza Tarapore ◽  
Kenji Fukasawa
Keyword(s):  
Cyclin E ◽  
Centrosome Duplication ◽  
Cyclin Dependent Kinase
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