The nuclear gene encodes an alternative oxidase that functions in mitochondria. The enzyme provides a branch from the standard electron transport chain by transferring electrons directly from ubiquinol to oxygen. In standard laboratory strains, is transcribed at very low levels under normal growth conditions. However, if the standard electron transport chain is disrupted, a mRNA expression is induced and the AOD1 protein is produced. We previously identified a strain of , that produces high levels of transcript under non-inducing conditions. Here we have crossed this strain to a standard lab strain and determined the genomic sequences of the parents and several progeny. Analysis of the sequence data and the levels of mRNA in uninduced cultures revealed that a frameshift mutation in the gene results in the high uninduced expression of The gene encodes a regulator of G protein signaling that decreases the activity of the Gα subunit of heterotrimeric G proteins. Our data suggest that strains with a functional gene prevent uninduced expression of by inactivating a G protein signaling pathway, and that this pathway is activated in cells grown under conditions that induce Induced cells with a deletion of the gene encoding the Gα protein still have a partial increase in mRNA levels, suggesting a second pathway for inducing transcription of the gene in We also present evidence that a translational control mechanism prevents production of AOD1 protein in uninduced cultures.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6778808 | PMC |
http://dx.doi.org/10.1534/g3.119.400522 | DOI Listing |
Sci Adv
January 2025
Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Mitochondrial electron transport chain (ETC) function modulates macrophage biology; however, mechanisms underlying mitochondria ETC control of macrophage immune responses are not fully understood. Here, we report that mutant mice with mitochondria ETC complex III (CIII)-deficient macrophages exhibit increased susceptibility to influenza A virus (IAV) and LPS-induced endotoxic shock. Cultured bone marrow-derived macrophages (BMDMs) isolated from these mitochondria CIII-deficient mice released less IL-10 than controls following TLR3 or TLR4 stimulation.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, MB, Canada.
Alternative oxidase (AOX) regulates the level of reactive oxygen species and nitric oxide (NO) in plants. While under normoxic conditions it alleviates NO formation, there are several indications that in the conditions of low oxygen such as during seed germination before radicle protrusion, in meristematic stem cells, and in flooded roots AOX can be involved in the production of NO from nitrite. Whereas the first reports considered this role as indirect, more evidence is accumulated that AOX can act as a nitrite: NO reductase.
View Article and Find Full Text PDFAntibiotics (Basel)
December 2024
School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
() infection causes tuberculosis (TB). TB is one of the most intractable infectious diseases, causing over 1.13 million deaths annually.
View Article and Find Full Text PDFbioRxiv
October 2024
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA.
Unlabelled: possess a remanent mitochondrion called the mitosome, which lacks DNA, the tricarboxylic acid cycle, a conventional electron transport chain, and ATP synthesis. The mitosome retains ubiquinone and iron sulfur cluster biosynthesis pathways, both of which require protein import that relies on the membrane potential. It was previously proposed that the membrane potential is generated by electrons transferred through an alternative respiratory pathway coupled to a transhydrogenase (TH) that pumps hydrogens out of the mitosome.
View Article and Find Full Text PDFPNAS Nexus
November 2024
Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
The titan arum (), commonly known as the corpse flower, produces the largest unbranched inflorescence in the world. Its rare blooms last only a few days and are notable both for their burst of thermogenic activity and for the odor of rotting flesh by which they attract pollinators. Studies on the titan arum can therefor lend insight into the mechanisms underlying thermogenesis as well as the production of sulfur-based volatiles, about which little is known in plants.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!