Correction to: Anaerobiosis revisited: growth of Saccharomyces cerevisiae under extremely low oxygen availability

Ixr1p from Saccharomyces cerevisiae has been previously studied because it binds to DNA containing intrastrand cross-links formed by the anticancer drug cisplatin. Ixr1p is also a transcriptional regulator of anaerobic/hypoxic genes, such as SRP1/TIR1, which encodes a stress-response cell wall manoprotein, and COX5B, which encodes the Vb subunit of the mitochondrial complex cytochrome c oxidase. However, factors controlling IXR1 expression remained unexplored. In the present study we show that IXR1 mRNA levels are controlled by oxygen availability and increase during hypoxia. In aerobiosis, low levels of IXR1 expression are maintained by Rox1p repression through the general co-repressor complex Tup1–Ssn6. Ixr1p itself is necessary for full IXR1 expression under hypoxic conditions. Deletion analyses have identified the region in the IXR1 promoter responsible for this positive auto-control (nucleotides −557 to −376). EMSA (electrophoretic mobility-shift assay) and ChIP (chromatin immunoprecipitation) assays show that Ixr1p binds to the IXR1 promoter both in vitro and in vivo. Ixr1p is also required for hypoxic repression of ROX1 and binds to its promoter. UPC2 deletion has opposite effects on IXR1 and ROX1 transcription during hypoxia. Ixr1p is also necessary for resistance to oxidative stress generated by H2O2. IXR1 expression is moderately activated by H2O2 and this induction is Yap1p-dependent. A model of IXR1 regulation as a relay for sensing different signals related to change in oxygen availability is proposed. In this model, transcriptional adaptation from aerobiosis to hypoxia depends on ROX1 and IXR1 cross-regulation.

Download Full-text

The Unique Phospholipidome of the Enteric Pathogen Campylobacter jejuni: Lysophosholipids Are Required for Motility at Low Oxygen Availability

Journal of Molecular Biology ◽

10.1016/j.jmb.2020.07.012 ◽

2020 ◽

Vol 432 (19) ◽

pp. 5244-5258 ◽

Cited By ~ 1

Author(s):

Xuefeng Cao ◽

Jos F.H.M. Brouwers ◽

Linda van Dijk ◽

Chris H.A. van de Lest ◽

Craig T. Parker ◽

...

Keyword(s):

Campylobacter Jejuni ◽

Oxygen Availability ◽

Enteric Pathogen ◽

Low Oxygen

Download Full-text

Oxygen Availability Provides a Signal for Hatching in the Rainbow Trout (Salmo gairdneri) Embryo

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-008 ◽

1989 ◽

Vol 46 (1) ◽

pp. 55-58 ◽

Cited By ~ 19

Author(s):

Keith E. Latham ◽

John J. Just

Keyword(s):

Rainbow Trout ◽

Developmental Time ◽

Critical Value ◽

Oxygen Availability ◽

Salmo Gairdneri ◽

Low Oxygen ◽

Partial Pressures

The hatching of rainbow trout (Salmo gairdneri) embryos can be stimulated by subjecting them to low oxygen partial pressures [Formula: see text] during the final days of incubation or delayed by elevating [Formula: see text]. Most embryos develop the ability to hatch between days 26 and 27 of incubation at 12 °C. During this time, similar hatching frequencies are obtained at any [Formula: see text] below a critical value in the 94–135 mm Hg (6.5–9.3 mg/L) range (1 mm Hg = 133.322 Pa). The [Formula: see text] required for continued incubation increases with developmental time such that hatching cannot be delayed beyond day 30 at 12 °C. These results indicate that oxygen availability influences the time at which trout embryos hatch and that hatching occurs when hatchable embryos are confronted with an ambient [Formula: see text] that is inadequate to satisfy aerobic metabolic requirements.

Download Full-text

Metabolic enzyme activities in swimming muscle of medusae: is the scaling of glycolytic activity related to oxygen availability?

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315405011537 ◽

2005 ◽

Vol 85 (3) ◽

pp. 603-611 ◽

Cited By ~ 19

Author(s):

Erik V. Thuesen ◽

Kelly D. McCullough ◽

James J. Childress

Keyword(s):

Body Size ◽

Citrate Synthase ◽

Krebs Cycle ◽

Glycolytic Enzyme ◽

Oxygen Availability ◽

Metabolic Enzyme ◽

Low Oxygen ◽

Cycle Enzyme ◽

Glycolytic Activity ◽

Two Populations

This study compared the scaling of the glycolytic enzyme lactate dehydrogenase (LDH) and the Krebs cycle enzyme citrate synthase (CS) in the swimming muscle and tentacle tissue of the mesopelagic coronate scyphomedusa Periphylla periphylla in two populations living under different oxygen minimum layer conditions. The LDH and CS activities in these tissues of two other coronate scyphomedusae (Paraphyllina ransoni and Periphyllopsis galatheae) and the bathypelagic narcomedusa Aegina citrea were also studied. The scaling of these two enzymes along with total protein was investigated in whole organism homogenates of the surface-living scyphomedusa Aurelia labiata. Mass-specific LDH activities in swimming muscle showed positive scaling in relation to body size in Periphylla periphylla collected off California and Hawaii. Mass-specific LDH activities in tentacle tissue increased with regards to increasing mass only in specimens of P. periphylla collected off California. The LDH values of the scaling coefficient, b, in swimming muscle and tentacle were significantly higher in P. periphylla collected in the low oxygen waters off California than from those collected off the Hawaiian Islands in a higher oxygen environment. The LDH showed a significant decrease with body size in Aegina citrea swimming muscle and in Aurelia labiata whole animal homogenates. The largest species in this study, Periphyllopsis galatheae, had LDH activities similar to the smallest specimens of Periphylla periphylla. The results of this study suggest that the scaling of glycolytic activity is related to oxygen availability for P. periphylla. In Aurelia labiata, which is only exposed to episodic hypoxia, and Aegina citrea, scaling of glycolytic activity is not affected by oxygen availability.

Download Full-text

Some Effects of Temporary Exposure to Low Dissolved Oxygen Levels on Pacific Salmon Eggs

Journal of the Fisheries Research Board of Canada ◽

10.1139/f58-013 ◽

1958 ◽

Vol 15 (2) ◽

pp. 229-250 ◽

Cited By ~ 91

Author(s):

D. F. Alderdice ◽

W. P. Wickett ◽

J. R. Brett

Keyword(s):

Oxygen Consumption ◽

Dissolved Oxygen ◽

Oxygen Demand ◽

Oxygen Availability ◽

Oncorhynchus Keta ◽

Hatching Rate ◽

Oxygen Level ◽

Low Oxygen ◽

Low Dissolved Oxygen ◽

Oxygen Levels

Eggs of the chum salmon (Oncorhynchus keta) were exposed to various constant levels of dissolved oxygen for a period of seven days. The procedure was repeated with fresh egg samples at various developmental stages. Temperatures were constant at 10 °C. from fertilization to hatching. Estimates of oxygen consumption uninhibited by low dissolved oxygen levels were obtained at various stages of egg development for whole eggs and also on the basis of the weight of larvae, excluding the yolk. Eggs were most sensitive to hypoxia between 100–200 Centigrade degree-days and compensated for reduced oxygen availability by reducing the oxygen demand and rate of development. Very low oxygen levels at early incubation stages resulted in the production of monstrosities. At about the time the circulatory system becomes functional the compensatory reduction in rate of growth under hypoxial conditions is reduced, but eggs no longer survive extreme hypoxial conditions. Eggs subjected to low dissolved oxygen levels just prior to hatching hatch prematurely at a rate dependent on the degree of hypoxia. The maximum premature hatching rate corresponded approximately with the median lethal oxygen level. Estimated median lethal levels rose slowly from fertilization to hatching. Oxygen consumption per egg rose from fertilization to hatching while the consumption per gram of larval tissue declined from a high to a low level at about the time of blastopore closure. Subsequently, a slight rise in the rate occurred up to a level which was more or less constant to hatching. "Critical" dissolved oxygen levels were calculated and they appear to define the oxygen level above which respiratory rate is unmodified by oxygen availability. Critical levels ranged from about 1 p.p.m. in early stages to over 7 p.p.m. shortly before hatching.

Download Full-text