Pexophagy Sensing and Signaling in the Methylotrophic Yeasts

Sibirny, Andriy А.

doi:10.1007/978-3-7091-1788-0_23

Cited by 3 publications

(2 citation statements)

References 91 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both these modes are complicated processes involving over 30 proteins named as Atg (autophagy-related proteins). The number and sequence of Atg involved in these two pexophagy processes have been widely studied ( Sibirny, 2014 ). Second, when P. pastoris grows in media containing methanol as the sole carbon source, the peroxisomes rapidly proliferate, reaching up to 40% of the cell volume.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Energy Charge as an Indicator of Pexophagy in Pichia pastoris

Zhang

Liu

2017

Front. Microbiol.

View full text Add to dashboard Cite

Pichia pastoris is a good model for pexophagy research owing to its diverse pexophagy modes (macropexophagy and micropexophagy) exhibited during carbon-source shift from methanol to other carbon sources. The critical condition that triggers activation of macropexophagy and micropexophagy is important for clarifying the P. pastoris pexophagy mechanism and human peroxisomal disorders. In this study, the pexophagy modes of P. pastoris were confirmed by green fluorescent protein expression and alcohol oxidase and formate dehydrogenase activities. Furthermore, intracellular energy charge (EC) was found to be a determinant of pexophagy activation. During methanol induction, the EC was about 0.5. And the final EC value was related to the pexophagy mode when carbon source switched from methanol to others. Macropexophagy and micropexophagy occurred when the EC increased to 0.6–0.75 and above 0.75, respectively. Thus, different EC values were considered as the important factor to trigger different pexophagy modes in P. pastoris. The results obtained in this study could help in achieving better control of the pexophagy modes to study the pexophagy mechanism.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Subsequently, Atg30 is shuttled to the vacuole along with the targeted peroxisome for degradation. However, the sensing and signaling of pexophagy need to be further investigated to understand the complete route ( Sibirny, 2014 ). Thus, a stable condition to trigger the activation of pexophagy is important for P. pastoris research.…”

Section: Introductionmentioning

confidence: 99%

Energy Charge as an Indicator of Pexophagy in Pichia pastoris

Zhang

Liu

2017

Front. Microbiol.

View full text Add to dashboard Cite

show abstract

Zinc cluster protein Znf1, a novel transcription factor of non-fermentative metabolism in Saccharomyces cerevisiae

Tangsombatvichit

Semkiv

Sibirny

et al. 2015

FEMS Yeast Research

View full text Add to dashboard Cite

The ability to rapidly respond to nutrient changes is a fundamental requirement for cell survival. Here, we show that the zinc cluster regulator Znf1 responds to altered nutrient signals following glucose starvation through the direct control of genes involved in non-fermentative metabolism, including those belonged to the central pathways of gluconeogenesis (PCK1, FBP1 and MDH2), glyoxylate shunt (MLS1 and ICL1) and the tricarboxylic acid cycle (ACO1), which is demonstrated by Znf1-binding enrichment at these promoters during the glucose-ethanol shift. Additionally, reduced Pck1 and Fbp1 enzymatic activities correlate well with the data obtained from gene transcription analysis. Cells deleted for ZNF1 also display defective mitochondrial morphology with unclear structures of the inner membrane cristae when grown in ethanol, in agreement with the substantial reduction in the ATP content, suggesting for roles of Znf1 in maintaining mitochondrial morphology and function. Furthermore, Znf1 also plays a role in tolerance to pH and osmotic stress, especially during the oxidative metabolism. Taken together, our results clearly suggest that Znf1 is a critical transcriptional regulator for stress adaptation during non-fermentative growth with some partial overlapping targets with previously reported regulators in Saccharomyces cerevisiae.

show abstract

Yeast peroxisomes: structure, functions and biotechnological opportunities

Sibirny

2016

FEMS Yeast Research

View full text Add to dashboard Cite

Peroxisomes are ubiquitous organelles found in most eukaryotic cells. In yeasts, peroxisomes play important roles in cell metabolism, especially in different catabolic processes including fatty acid β-oxidation, the glyoxylic shunt and methanol metabolism, as well as some biosynthetic processes. In addition, peroxisomes are the compartment in which oxidases and catalase are localized. New peroxisomes mainly arise by fission of pre-existing ones, although they can also be formed from the endoplasmic reticulum (ER). Peroxisomes consist of matrix-soluble proteins and membrane proteins known as peroxins. A total of 34 PEX peroxin genes and proteins have been identified to date. and their functions have been elucidated. Protein import into peroxisomes depends on peroxins and requires specific signals in the structure of transported proteins: PTS1, PTS2 and mPTS. The mechanisms of metabolite penetration into peroxisomes are still poorly understood. Peroxisome number and the volume occupied by these organelles are tightly regulated. Methanol, fatty acids and methylamine act as efficient peroxisome proliferators, whereas glucose and ethanol induce peroxisome autophagic degradation (pexophagy). To date, 42 Atg proteins involved in pexophagy are known. Catabolism and alcoholic fermentation of the major pentose sugar, xylose, depend on peroxisomal enzymes. Overexpression of peroxisomal transketolase and transaldolase activates xylose fermentation. Peroxisomes could be useful as target organelles for overexpression of foreign toxic proteins.

show abstract

Pexophagy Sensing and Signaling in the Methylotrophic Yeasts

Cited by 3 publications

References 91 publications

Energy Charge as an Indicator of Pexophagy in Pichia pastoris

Energy Charge as an Indicator of Pexophagy in Pichia pastoris

Zinc cluster protein Znf1, a novel transcription factor of non-fermentative metabolism in Saccharomyces cerevisiae

Yeast peroxisomes: structure, functions and biotechnological opportunities

Contact Info

Product

Resources

About