scholarly journals A Conserved PP2A Regulatory Subunit Enforces Proportional Relationships Between Cell Size and Growth Rate

Genetics ◽  
2019 ◽  
Vol 213 (2) ◽  
pp. 517-528 ◽  
Author(s):  
Ricardo M. Leitao ◽  
Akshi Jasani ◽  
Rafael A. Talavera ◽  
Annie Pham ◽  
Quincy J. Okobi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cell Size ◽  
Regulatory Subunit

scholarly journals Cell size and growth rate are modulated by TORC2-dependent signals

2017 ◽  
Author(s):  
Rafael Lucena ◽  
Maria Alcaide-Gavilán ◽  
Katherine Schubert ◽  
Maybo He ◽  
Matthew Domnauer ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cell Size ◽  
Nutrient Availability ◽  
Feedback Loop ◽  
Budding Yeast ◽  
Regulatory Subunit ◽  
Underlying Mechanisms

SummaryThe size of all cells, from bacteria to vertebrates, is proportional to the growth rate set by nutrient availability, but the underlying mechanisms are unknown. Here, we show that nutrients modulate TORC2 signaling, and that cell size is proportional to TORC2 signaling in budding yeast. The TORC2 network controls production of ceramide lipids, which play roles in signaling. We discovered that ceramide-dependent signals control both growth rate and cell size. Thus, cells that can not make ceramides fail to modulate their growth rate or size in response to changes in nutrients. PP2A associated with the Rts1 regulatory subunit (PP2ARts1) is embedded in a feedback loop that controls TORC2 signaling and plays an important role in mechanisms that modulate TORC2 signaling in response to nutrients. Together, the data suggest a model in which growth rate and cell size are mechanistically linked by ceramide-dependent signals arising from the TORC2 network.

scholarly journals PP2ARts1enforces a proportional relationship between cell size and growth rate

2018 ◽  
Author(s):  
Ricardo M. Leitao ◽  
Annie Pham ◽  
Quincy Okobi ◽  
Douglas R. Kellogg
Keyword(s):  
Growth Rate ◽  
Cell Size ◽  
Cell Cycle Progression ◽  
Mechanistic Explanation ◽  
Regulatory Subunit ◽  
Daughter Cells ◽  
Duration Of Mitosis ◽  
Proportional Relationship ◽  
Underlying Mechanisms ◽  
The Relationship

AbstractCell size is proportional to growth rate. Thus, cells growing slowly in poor nutrients can be nearly half the size of cells growing rapidly in rich nutrients. The relationship between cell size and growth rate appears to hold across all orders of life, yet the underlying mechanisms are unknown. In budding yeast, most growth occurs during mitosis, and the proportional relationship between cell size and growth rate is therefore enforced primarily by modulating growth in mitosis. When growth is slow, the duration of mitosis is increased to allow more time for growth, yet the amount of growth required to complete mitosis is reduced, leading to birth of small daughter cells. Previous studies found that PP2A associated with the Rts1 regulatory subunit (PP2ARts1) works in a TORC2-dependent feedback loop that sets cell size and growth rate to match nutrient availability. However, it was unknown whether PP2ARts1influences growth in mitosis. Here, we show that PP2ARts1is required for the proportional relationship between cell size and growth rate during mitosis. Moreover, nutrients and PP2ARts1influence the duration of mitosis, and thus the extent of growth in mitosis, via Wee1 and Pds1/securin, two conserved regulators of mitotic progression. Together, the data suggest a model in which the same global signals that set growth rate also set the critical amount of growth required for cell cycle progression, which would provide a simple mechanistic explanation for the proportional relationship between size and growth rate.

scholarly journals Covariation of metabolic rates and cell size in coccolithophores

2015 ◽  
Vol 12 (15) ◽  
pp. 4665-4692 ◽  
Author(s):  
G. Aloisi
Keyword(s):  
Growth Rate ◽  
Environmental Change ◽  
Cell Size ◽  
Environmental Conditions ◽  
Laboratory Experiments ◽  
Opposite Effect ◽  
Cell Structure ◽  
Metabolic Rates ◽  
The Future ◽  
Phytoplankton Group

Abstract. Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size). I show that growth, photosynthesis and, to a lesser extent, calcification covary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature (below the optimum temperature for growth) produces the opposite effect. The magnitude of the coccosphere-size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment–metabolism–size link are understood, it will be possible to use coccosphere-size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. The coccolithophore database is strongly biased in favour of experiments with the coccolithophore Emiliania huxleyi (E. huxleyi; 82 % of database entries), and more experiments with other species are needed to understand whether these observations can be extended to coccolithophores in general. I introduce a simple model that simulates the growth rate and the size of cells forced by nitrate and phosphate concentrations. By considering a simple rule that allocates the energy flow from nutrient acquisition to cell structure (biomass) and cell maturity (biological complexity, eventually leading to cell division), the model is able to reproduce the covariation of growth rate and cell size observed in laboratory experiments with E. huxleyi when these nutrients become limiting. These results support ongoing efforts to interpret coccosphere and coccolith size measurements in the context of climate change.

The effect of cell size on cellular Zn and Cd and Zn‐Cd‐CO 2 colimitation of growth rate in marine diatoms

2020 ◽  
Vol 65 (12) ◽  
pp. 2896-2911
Author(s):  
Weiying Li ◽  
William G. Sunda ◽  
Wenfang Lin ◽  
Haizheng Hong ◽  
Dalin Shi
Keyword(s):  
Growth Rate ◽  
Cell Size ◽  
Marine Diatoms

scholarly journals Biphasic Cell-Size and Growth-Rate Homeostasis by Single Bacillus subtilis Cells

2020 ◽  
Vol 30 (12) ◽  
pp. 2238-2247.e5 ◽  
Author(s):  
Niclas Nordholt ◽  
Johan H. van Heerden ◽  
Frank J. Bruggeman
Keyword(s):  
Growth Rate ◽  
Bacillus Subtilis ◽  
Cell Size

Components of the Variability of Radial Cell Size in Tree Rings of Conifers

IAWA Journal ◽  
1989 ◽  
Vol 10 (4) ◽  
pp. 417-426 ◽  
Author(s):  
L.G. Vysotskaya ◽  
E.A. Vaganov
Keyword(s):  
Growth Rate ◽  
Soil Moisture ◽  
Cell Size ◽  
Climatic Factors ◽  
Size Variation ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Radial Cell ◽  
Natural Stands ◽  
Main Components

Radial cell size of conifers of three speeies: Pinus sylvestris, Larix sibirica, and Larix gmelinii from natural stands in the south of the Krasnoyarsk region (USSR) have been measured with a semi-automated device. The main factors responsible for cell size variation have been determined. These are: age, growth rate, soil moisture, climatic changes and endogenous rhythm of cell growth. Age greatly affects the radial cell size in trees up to 30 years old. Growth rate only affects radial tracheid diameter in narrow rings of 0 to 0.5 mm. The main components of variation: soil moisture, climatic factors and a cyclic component have been estimated for pines from three different conditions of moisture: moist, moderately moist and dry. It was shown, that under optimal growth conditions the contribution of the endogenous component was more or less equal to that of the climatic component.

scholarly journals PP2ARts1 is a master regulator of pathways that control cell size

2014 ◽  
Vol 204 (3) ◽  
pp. 359-376 ◽  
Author(s):  
Jessica Zapata ◽  
Noah Dephoure ◽  
Tracy MacDonough ◽  
Yaxin Yu ◽  
Emily J. Parnell ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Size ◽  
Control Cell ◽  
Size Control ◽  
Regulatory Subunit ◽  
Delay Cell ◽  
Cell Cycle Entry ◽  
G1 Cyclin

Cell size checkpoints ensure that passage through G1 and mitosis occurs only when sufficient growth has occurred. The mechanisms by which these checkpoints work are largely unknown. PP2A associated with the Rts1 regulatory subunit (PP2ARts1) is required for cell size control in budding yeast, but the relevant targets are unknown. In this paper, we used quantitative proteome-wide mass spectrometry to identify proteins controlled by PP2ARts1. This revealed that PP2ARts1 controls the two key checkpoint pathways thought to regulate the cell cycle in response to cell growth. To investigate the role of PP2ARts1 in these pathways, we focused on the Ace2 transcription factor, which is thought to delay cell cycle entry by repressing transcription of the G1 cyclin CLN3. Diverse experiments suggest that PP2ARts1 promotes cell cycle entry by inhibiting the repressor functions of Ace2. We hypothesize that control of Ace2 by PP2ARts1 plays a role in mechanisms that link G1 cyclin accumulation to cell growth.

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