Mitophagy, mitochondrial dynamics and the general stress response in yeast

2011 ◽  
Vol 39 (5) ◽  
pp. 1514-1519 ◽  
Author(s):  
Matthias Müller ◽  
Andreas S. Reichert
Keyword(s):  
Quality Control ◽  
Stress Response ◽  
Neurodegenerative Disorders ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Nutrient Sensing ◽  
Control Mechanisms ◽  
General Stress Response ◽  
General Stress

Autophagy is a fundamental cellular process promoting survival under various environmental stress conditions. Selective types of autophagy have gained much interest recently as they are involved in specific quality control mechanisms removing, for example, aggregated proteins or dysfunctional mitochondria. This is considered to counteract the development of a number of neurodegenerative disorders and aging. Here we review the role of mitophagy and mitochondrial dynamics in ensuring quality control of mitochondria. In particular, we provide possible explanations why mitophagy in yeast, in contrast with the situation in mammals, was found to be independent of mitochondrial fission. We further discuss recent findings linking these processes to nutrient sensing pathways and the general stress response in yeast. In particular, we propose a model for how the stress response protein Whi2 and the Ras/PKA (protein kinase A) signalling pathway are possibly linked and thereby regulate mitophagy.

Abstract P049: Circadian Clock Dysfunction Impairs Mitochondrial Fitness And Contributes To Myocardial Ischemic Injury

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Inna Rabinovich-Nikitin ◽  
Illana Posen ◽  
Victoria Margulets ◽  
Tami A Martino ◽  
Lorrie A Kirshenbaum
Keyword(s):  
Quality Control ◽  
Cell Viability ◽  
Circadian Clock ◽  
Cardiac Myocytes ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Control Mechanisms ◽  
Complex Activity ◽  
Mitochondrial Dynamic

Cardiac function is highly reliant on mitochondrial oxidative metabolism and fitness. The circadian clock is critically linked to vital physiological process including mitochondrial fission, fusion and quality control mechanisms. However, little is known of how the circadian clock regulates these vital processes in the heart. Herein, we identified a putative circadian Clock - mitochondrial interactome that gates an adaptive stress response for cell viability during myocardial ischemia reperfusion (I-R) injury. We show that Clock transcriptionally coordinates expression of mitochondrial dynamic fusion and fission, bioenergetic and quality control proteins in cardiac myocytes. Transcriptome and gene ontology mapping revealed Clock defective hearts subjected to I-R exhibited major transcriptional deficits in several key survival processes including mitochondrial dynamics, bioenergetics and autophagy that were reduced further following I-R. Gain of function of Clock activity re-established gene transcription of mitochondrial respiratory complex activity, quality control mechanisms and cell viability. Collectively, our data show that mitochondrial fitness and cell survival is mutually dependent upon and obligatorily linked to transcription of the circadian Clock gene in cardiac myocytes. Our data suggest the functional loss of Clock activity predisposes cardiac myocytes to metabolic catastrophe. Hence, therapeutic strategies designed to preserve circadian clock activity in the hearts may prove beneficial in reducing morbidity and mortality following ischemia -related pathologies such as myocardial infarction.

scholarly journals Role of Sphingomonas sp. Strain Fr1 PhyR-NepR- EcfG Cascade in General Stress Response and Identification of a Negative Regulator of PhyR

2011 ◽  
Vol 193 (23) ◽  
pp. 6629-6638 ◽  
Author(s):  
A. Kaczmarczyk ◽  
S. Campagne ◽  
F. Danza ◽  
L. C. Metzger ◽  
J. A. Vorholt ◽  
...  
Keyword(s):  
Stress Response ◽  
Negative Regulator ◽  
General Stress Response ◽  
General Stress

scholarly journals The Hsp40 Mas5 Connects Protein Quality Control and the General Stress Response through the Thermo-sensitive Pyp1

iScience ◽  
2020 ◽  
Vol 23 (11) ◽  
pp. 101725 ◽  
Author(s):  
Susanna Boronat ◽  
Luis Marte ◽  
Montserrat Vega ◽  
Sarela García-Santamarina ◽  
Margarita Cabrera ◽  
...  
Keyword(s):  
Quality Control ◽  
Stress Response ◽  
Protein Quality ◽  
Protein Quality Control ◽  
General Stress Response ◽  
General Stress

scholarly journals Role of the PFXFATG[G/Y] Motif in the Activation of SdrG, a Response Regulator Involved in the Alphaproteobacterial General Stress Response

Structure ◽  
2016 ◽  
Vol 24 (8) ◽  
pp. 1237-1247 ◽  
Author(s):  
Sébastien Campagne ◽  
Sebastian Dintner ◽  
Lisa Gottschlich ◽  
Maxence Thibault ◽  
Miriam Bortfeld-Miller ◽  
...  
Keyword(s):  
Stress Response ◽  
Response Regulator ◽  
General Stress Response ◽  
General Stress

The modulator of the general stress response, MgsR, ofBacillus subtilisis subject to multiple and complex control mechanisms

2012 ◽  
Vol 14 (10) ◽  
pp. 2838-2850 ◽  
Author(s):  
Alexander Reder ◽  
Dierk-Christoph Pöther ◽  
Ulf Gerth ◽  
Michael Hecker
Keyword(s):  
Stress Response ◽  
Control Mechanisms ◽  
General Stress Response ◽  
Complex Control ◽  
General Stress

scholarly journals Thermal and Nutritional Regulation of Ribosome Hibernation inStaphylococcus aureus

2018 ◽  
Vol 200 (24) ◽  
Author(s):  
Arnab Basu ◽  
Kathryn E. Shields ◽  
Christopher S. Eickhoff ◽  
Daniel F. Hoft ◽  
Mee-Ngan F. Yap
Keyword(s):  
Staphylococcus Aureus ◽  
Transcription Factor ◽  
Stress Response ◽  
Nutrient Sensing ◽  
Dependent Manner ◽  
Nutritional Regulation ◽  
Content Type ◽  
General Stress Response ◽  
Regulatory Pathways ◽  
General Stress

ABSTRACTThe translationally silent 100S ribosome is a poorly understood form of the dimeric 70S complex that is ubiquitously found in all bacterial phyla. The elimination of the hibernating 100S ribosome leads to translational derepression, ribosome instability, antibiotic sensitivity, and biofilm defects in some bacteria. InFirmicutes, such as the opportunistic pathogenStaphylococcus aureus, a 190-amino acid protein calledhibernating-promotingfactor (HPF) dimerizes and conjoins two 70S ribosomes through a direct interaction between the HPF homodimer, with each HPF monomer tethered on an individual 70S complex. While the formation of the 100S ribosome in gammaproteobacteria and cyanobacteria is exclusively induced during postexponential growth phase and darkness, respectively, the 100S ribosomes inFirmicutesare constitutively produced from the lag-logarithmic phase through the post-stationary phase. Very little is known about the regulatory pathways that controlhpfexpression and 100S ribosome abundance. Here, we show that a general stress response (GSR) sigma factor (SigB) and a GTP-sensing transcription factor (CodY) integrate nutrient and thermal signals to regulatehpfsynthesis inS. aureus, resulting in an enhanced virulence of the pathogen in a mouse model of septicemic infection. CodY-dependent regulation ofhpfis strain specific. An epistasis analysis further demonstrated that CodY functions upstream of the GSR pathway in a condition-dependent manner. The results reveal an important link betweenS. aureusstress physiology, ribosome metabolism, and infection biology.IMPORTANCEThe dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogenStaphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor ofhpfexpression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation ofhpfmasks a secondaryhpftranscript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites.

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