Cell Cycle and Organelle Division Cycle in Cyanidioschyzon merolae

2017 ◽  
pp. 177-185
Author(s):  
Takayuki Fujiwara
Keyword(s):  
Cell Cycle ◽  
Cyanidioschyzon Merolae ◽  
Organelle Division

scholarly journals Cell Cycle-regulated, Microtubule-independent Organelle Division in Cyanidioschyzon merolae

2005 ◽  
Vol 16 (5) ◽  
pp. 2493-2502 ◽  
Author(s):  
Keiji Nishida ◽  
Fumi Yagisawa ◽  
Haruko Kuroiwa ◽  
Toshiyuki Nagata ◽  
Tsuneyoshi Kuroiwa
Keyword(s):  
Cell Cycle ◽  
Spindle Pole ◽  
Chloroplast Division ◽  
Mitochondrial Morphology ◽  
Cyanidioschyzon Merolae ◽  
Microtubule Organization ◽  
Mitochondrial Division ◽  
Protein Levels ◽  
Division Site ◽  
Organelle Division

Mitochondrial and chloroplast division controls the number and morphology of organelles, but how cells regulate organelle division remains to be clarified. Here, we show that each step of mitochondrial and chloroplast division is closely associated with the cell cycle in Cyanidioschyzon merolae. Electron microscopy revealed direct associations between the spindle pole bodies and mitochondria, suggesting that mitochondrial distribution is physically coupled with mitosis. Interconnected organelles were fractionated under microtubule-stabilizing condition. Immunoblotting analysis revealed that the protein levels required for organelle division increased before microtubule changes upon cell division, indicating that regulation of protein expression for organelle division is distinct from that of cytokinesis. At the mitochondrial division site, dynamin stuck to one of the divided mitochondria and was spatially associated with the tip of a microtubule stretching from the other one. Inhibition of microtubule organization, proteasome activity or DNA synthesis, respectively, induced arrested cells with divided but shrunk mitochondria, with divided and segregated mitochondria, or with incomplete mitochondrial division restrained at the final severance, and repetitive chloroplast division. The results indicated that mitochondrial morphology and segregation but not division depend on microtubules and implied that the division processes of the two organelles are regulated at distinct checkpoints.

scholarly journals Chloroplast division checkpoint in eukaryotic algae

2016 ◽  
Vol 113 (47) ◽  
pp. E7629-E7638 ◽  
Author(s):  
Nobuko Sumiya ◽  
Takayuki Fujiwara ◽  
Atsuko Era ◽  
Shin-ya Miyagishima
Keyword(s):  
Cell Cycle ◽  
Host Cell ◽  
Cell Cycle Progression ◽  
Chloroplast Division ◽  
Dominant Negative ◽  
Cyanidioschyzon Merolae ◽  
Temperature Sensitive ◽  
Specific Expression ◽  
Cycle Progression ◽  
Division Site

Chloroplasts evolved from a cyanobacterial endosymbiont. It is believed that the synchronization of endosymbiotic and host cell division, as is commonly seen in existing algae, was a critical step in establishing the permanent organelle. Algal cells typically contain one or only a small number of chloroplasts that divide once per host cell cycle. This division is based partly on the S-phase–specific expression of nucleus-encoded proteins that constitute the chloroplast-division machinery. In this study, using the red alga Cyanidioschyzon merolae, we show that cell-cycle progression is arrested at the prophase when chloroplast division is blocked before the formation of the chloroplast-division machinery by the overexpression of Filamenting temperature-sensitive (Fts) Z2-1 (Fts72-1), but the cell cycle progresses when chloroplast division is blocked during division-site constriction by the overexpression of either FtsZ2-1 or a dominant-negative form of dynamin-related protein 5B (DRP5B). In the cells arrested in the prophase, the increase in the cyclin B level and the migration of cyclin-dependent kinase B (CDKB) were blocked. These results suggest that chloroplast division restricts host cell-cycle progression so that the cell cycle progresses to the metaphase only when chloroplast division has commenced. Thus, chloroplast division and host cell-cycle progression are synchronized by an interactive restriction that takes place between the nucleus and the chloroplast. In addition, we observed a similar pattern of cell-cycle arrest upon the blockage of chloroplast division in the glaucophyte alga Cyanophora paradoxa, raising the possibility that the chloroplast division checkpoint contributed to the establishment of the permanent organelle.

Characterization of cell-cycle-driven and light-driven gene expression in a synchronous culture system in the unicellular rhodophyte Cyanidioschyzon merolae

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1730-1737 ◽  
Author(s):  
Takashi Moriyama ◽  
Kimihiro Terasawa ◽  
Kohsuke Sekine ◽  
Masakazu Toyoshima ◽  
Mika Koike ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Culture System ◽  
Cell Cycle Progression ◽  
Light Period ◽  
Cyanidioschyzon Merolae ◽  
Synchronous Culture ◽  
Expression Of Genes ◽  
Cyclin C

The unicellular rhodophyte Cyanidioschyzon merolae, having a single plastid and a single mitochondrion, is suitable for the analysis of the cell cycle involving the division of organelles. In conventional methods of synchronous culture of algae, light/dark cycles have been used as signals for synchronization, and the gene expression promoted by light is not separated from the gene expression related to cell cycle progression. We previously devised a novel synchronous culture system with controlled photosynthesis, which is triggered by 6 h-light/18 h-dark cycles combined with different levels of CO2. The cells do not enter S-phase and consequently do not divide after the minimum light period without CO2 supplementation, but do divide after a light period with 1 % CO2. In this way, we can compare a dividing cycle and a non-dividing cycle. We examined changes in the expression of 74 genes throughout the cell cycle by quantitative RT-PCR. The expression of genes for two cyclins (cyclin C and H) and two CDKs (CDKA and CDKD) as well as metabolic enzymes was promoted by light, whereas the expression of genes for G1/S or G2/M cyclins and CDKs as well as DNA replication enzymes and proteins related to organellar division was promoted only in the dividing cycles. These results suggested that C. merolae has a checkpoint for G1/S progression, which is regulated by nutrients within the 6 h light period.

The cell cycle, including the mitotic cycle and organelle division cycles, as revealed by cytological observations

Microscopy ◽  
2011 ◽  
Vol 60 (suppl 1) ◽  
pp. S117-S136 ◽  
Author(s):  
Y. Imoto ◽  
Y. Yoshida ◽  
F. Yagisawa ◽  
H. Kuroiwa ◽  
T. Kuroiwa
Keyword(s):  
Cell Cycle ◽  
Mitotic Cycle ◽  
Organelle Division

scholarly journals CZON-cutter: a CRISPR-Cas9 system with multiplexed organelle imaging in a simple unicellular alga

2021 ◽  
Author(s):  
Yamato Yoshida ◽  
Naoto Tanaka ◽  
Yuko Mogi ◽  
Takayuki Fujiwara ◽  
Kannosuke Yabe ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cellular Structure ◽  
Fluorescent Protein ◽  
Protein Labeling ◽  
Cyanidioschyzon Merolae ◽  
Unicellular Alga ◽  
Guide Rna ◽  
Biological Features ◽  
Algal Genome ◽  
High Throughput Manner

The simple cellular structure of the unicellular alga Cyanidioschyzon merolae consists of one nucleus, one mitochondrion, one chloroplast, and one peroxisome per cell and offers unique advantages to investigate mechanisms of organellar proliferation and the cell cycle. Here, we describe an engineered clustered, regularly interspaced, short palindromic repeats (CRISPR)-associated protein 9 (Cas9) system, CZON-cutter, for simultaneous genome editing and organellar visualization. We engineered a C. merolae strain expressing a nuclear-localized Cas9-Venus nuclease to target editing at a locus defined by a single-guide RNA (sgRNA). We then successfully edited the algal genome and visualized the mitochondrion and peroxisome in transformants by fluorescent protein reporters with different excitation wavelengths. Fluorescent protein labeling of organelles in living transformants allows validation of phenotypes associated with organellar proliferation and the cell cycle, even when the edited gene is essential. Combined with the exceptional biological features of C. merolae, CZON-cutter will be instrumental for investigating cellular and organellar division in a high-throughput manner.

scholarly journals A single master regulator controls asexual cell cycle division patterns in Toxoplasma gondii

2020 ◽  
Author(s):  
Asma S. Khelifa ◽  
Cecilia Sanchez Guillen ◽  
Kevin M. Lesage ◽  
Ludovic Huot ◽  
Pierre Pericard ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Toxoplasma Gondii ◽  
Molecular Mechanisms ◽  
Cell Cycle Control ◽  
Life Cycles ◽  
Specific Cell ◽  
Master Regulator ◽  
Apicomplexan Parasites ◽  
Organelle Division ◽  
Single Nucleus

ABSTRACTAll apicomplexan parasites have complex life cycles exhibiting division characterized by a tightly regulated cell cycle control, resulting in the emergence of daughter parasites in possession of a single nucleus and a complete set of organelles. Apicomplexa have evolved efficient and distinctive strategies for intracellular replication where the timing of emergence of the daughter cells, a process termed “budding”, is a decisive element. However, the molecular mechanisms that provide the proper timing of parasite budding remain unknown. Using Toxoplasma gondii as a model Apicomplexa, we identified a master regulator that controls the timing of the budding process. We show that an ApiAP2 transcription factor, TgAP2IX-5, controls cell cycle events downstream of centrosome duplication including organelle division and segregation. TgAP2IX-5 binds to the promoter of hundreds of genes and controls the activation of the budding-specific cell cycle expression program. We show that TgAP2IX-5 regulates the expression of specific transcription factors that are necessary for the completion of the budding cycle. TgAP2IX-5 acts as a licensing factor that ensures that asexual proliferation continues by promoting the inhibition of the differentiation pathway at each round of the cell cycle. Therefore, TgAP2IX-5 is a master regulator that controls both cell cycle and developmental pathways.

scholarly journals Dynamics of the nucleoside diphosphate kinase protein DYNAMO2 correlates with the changes in the global GTP level during the cell cycle of Cyanidioschyzon merolae

2019 ◽  
Vol 95 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Yuuta IMOTO ◽  
Yuichi ABE ◽  
Kanji OKUMOTO ◽  
Mio OHNUMA ◽  
Haruko KUROIWA ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Nucleoside Diphosphate Kinase ◽  
Cyanidioschyzon Merolae
Sign in / Sign up

Export Citation Format

Share Document