Rat mitochondrial ATP synthase ATP5G3: cloning and upregulation in pancreas after chronic ethanol feeding

2001 ◽  
Vol 6 (2) ◽  
pp. 91-98 ◽  
Author(s):  
HA-SHENG LI ◽  
JI-YING ZHANG ◽  
BRYAN S. THOMPSON ◽  
XIAO-YING DENG ◽  
MICHAEL E. FORD ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Cellular Response ◽  
Molecular Mechanisms ◽  
Metabolic Stress ◽  
Nuclear Gene ◽  
Chronic Ethanol ◽  
Ethanol Ingestion ◽  
Pancreatic Acinar Cells ◽  
Mitochondrial Atp Synthase ◽  
Ethanol Feeding

Individuals with chronic excessive alcohol ingestion are put at the risk of acute and chronic pancreatitis. Underlying molecular mechanisms are unknown. Differential gene expression in the pancreas was profiled using mRNA differential display by comparison between control and ethanol-consuming rats. Male Wistar rats were fed with diets containing 6.7% (vol/vol) ethanol for 4 wk. A cDNA tag that was overexpressed in the pancreas of rats fed ethanol was isolated. A 723-bp cDNA was cloned from a rat pancreatic cDNA library, which encodes a novel rat mitochondrial ATP synthase subunit 9, isoform 3 (ATP5G3), which is homologous to a human ATP5G3 gene. Real-time PCR demonstrated that all three nuclear gene isoforms (ATP5G1, ATP5G2, and ATP5G3) were consistently upregulated in the pancreas of alcohol-consuming rats, parallel with mitochondrial injury. The cellular response to mitochondrial damage and metabolic stress may reflect an adaptive process for mitochondrial repair in pancreatic acinar cells during chronic ethanol ingestion.

scholarly journals The effect of chronic ethanol ingestion on synthesis and degradation of soluble, contractile and stromal protein fractions of skeletal muscles from immature and mature rats

1989 ◽  
Vol 259 (1) ◽  
pp. 261-266 ◽  
Author(s):  
V R Preedy ◽  
T J Peters
Keyword(s):  
Protein Synthesis ◽  
Ethanol Exposure ◽  
Chronic Ethanol ◽  
Protein Fractions ◽  
Ethanol Ingestion ◽  
Ethanol Treatment ◽  
Male Wistar Rats ◽  
Ethanol Feeding ◽  
The Difference ◽  
Stromal Proteins

1. An investigation was carried out into the response of soluble, myofibrillar and stromal protein fractions of skeletal muscle to chronic ethanol feeding. Groups of male Wistar rats, of approx. 85 or 280 g body wt., were pair-fed on a nutritionally complete liquid diet containing glucose or a diet in which 36% of the total energy was provided by ethanol. After 6 weeks, rates of protein synthesis were measured with a flooding dose of L-[4-3H]phenylalanine. 2. The protein contents of soluble, myofibrillar and stromal fractions in gastrocnemius muscle from small and large rats were decreased by ethanol feeding. Greater changes were observed in small than in large rats. 3. Fractional synthesis rates of soluble, myofibrillar and stromal proteins of gastrocnemius were all decreased by ethanol treatment. All fractions responded similarly, though percentage decreases in large rats were greater than in small rats. Absolute synthesis rates in gastrocnemius muscles were also decreased after ethanol treatment. All protein fractions responded similarly, and the magnitudes of the responses in large and small rats were also similar. 4. Fractional rates of breakdown, measured by the difference between fractional growth and synthesis rates, were apparently decreased, in both sets of rats, in all protein fractions. 5. It was concluded that chronic ethanol exposure causes perturbations in soluble, myofibrillar and stromal protein accretion by a mechanism involving unidirectional changes in protein synthesis and possibly breakdown.

scholarly journals An Algal Nucleus-encoded Subunit of Mitochondrial ATP Synthase Rescues a Defect in the Analogous Human Mitochondrial-encoded Subunit

2002 ◽  
Vol 13 (11) ◽  
pp. 3836-3844 ◽  
Author(s):  
Joseline Ojaimi ◽  
Junmin Pan ◽  
Sumana Santra ◽  
William J. Snell ◽  
Eric A. Schon
Keyword(s):  
Atp Synthase ◽  
Nuclear Gene ◽  
Mitochondrial Diseases ◽  
Atp Synthesis ◽  
Single Copy ◽  
Human Cells ◽  
Mitochondrial Targeting ◽  
Mitochondrial Atp Synthase ◽  
Targeting Signal ◽  
Atpase 6

Unlike most organisms, the mitochondrial DNA (mtDNA) ofChlamydomonas reinhardtii, a green alga, does not encode subunit 6 of F0F1-ATP synthase. We hypothesized that C. reinhardtii ATPase 6 is nucleus encoded and identified cDNAs and a single-copy nuclear gene specifying this subunit (CrATP6, with eight exons, four of which encode a mitochondrial targeting signal). Although the algal and humanATP6 genes are in different subcellular compartments and the encoded polypeptides are highly diverged, their secondary structures are remarkably similar. When CrATP6 was expressed in human cells, a significant amount of the precursor polypeptide was targeted to mitochondria, the mitochondrial targeting signal was cleaved within the organelle, and the mature polypeptide was assembled into human ATP synthase. In spite of the evolutionary distance between algae and mammals, C. reinhardtii ATPase 6 functioned in human cells, because deficiencies in both cell viability and ATP synthesis in transmitochondrial cell lines harboring a pathogenic mutation in the human mtDNA-encoded ATP6 gene were overcome by expression of CrATP6. The ability to express a nucleus-encoded version of a mammalian mtDNA-encoded protein may provide a way to import other highly hydrophobic proteins into mitochondria and could serve as the basis for a gene therapy approach to treat human mitochondrial diseases.

scholarly journals Mutations in the mitochondrial ATP synthase gamma subunit suppress a slow-growth phenotype of yme1 yeast lacking mitochondrial DNA.

Genetics ◽  
1995 ◽  
Vol 140 (2) ◽  
pp. 435-442 ◽  
Author(s):  
E R Weber ◽  
R S Rooks ◽  
K S Shafer ◽  
J W Chase ◽  
P E Thorsness
Keyword(s):  
Mitochondrial Dna ◽  
Atp Synthase ◽  
Slow Growth ◽  
Carbon Sources ◽  
Nuclear Gene ◽  
Genomic Locus ◽  
Gamma Subunit ◽  
Mitochondrial Atp Synthase ◽  
Growth Phenotype ◽  
Slow Growth Phenotype

Abstract In Saccharomyces cerevisiae, inactivation of the nuclear gene YME1 causes several phenotypes associated with impairment of mitochondrial function. In addition to deficiencies in mitochondrial compartment integrity and respiratory growth, yme1 mutants grow extremely slowly in the absence of mitochondrial DNA. We have identified two genetic loci that, when mutated, act as dominant suppressors of the slow-growth phenotype of yme1 strains lacking mitochondrial DNA. These mutations only suppressed the slow-growth phenotype of yme1 strains lacking mitochondrial DNA and had no effect on other phenotypes associated with yme1 mutations. One allele of one linkage group had a collateral respiratory deficient phenotype that allowed the isolation of the wild-type gene. This suppressing mutation was in ATP3, a gene that encodes the gamma subunit of the mitochondrial ATP synthase. Recovery of two of the suppressing ATP3 alleles and subsequent sequence analysis placed the suppressing mutations at strictly conserved residues near the C terminus of Atp3p. Deletion of the ATP3 genomic locus resulted in an inability to utilize nonfermentable carbon sources. atp3 deletion strains lacking mitochondrial DNA grew slowly on glucose media but were not as compromised for growth as yme1 yeast lacking mitochondrial DNA.

In Silico Repurposing of J147 for Neonatal Encephalopathy Treatment: Exploring Molecular Mechanisms of Mutant Mitochondrial ATP Synthase

2020 ◽  
Vol 21 (14) ◽  
pp. 1551-1566
Author(s):  
Iwuchukwu A. Emmanuel ◽  
Fisayo A. Olotu ◽  
Clement Agoni ◽  
Mahmoud E.S. Soliman
Keyword(s):  
Drug Design ◽  
Atp Synthase ◽  
Molecular Mechanisms ◽  
Conformational Transition ◽  
Binding Energies ◽  
Wild Type ◽  
Neonatal Encephalopathy ◽  
Wild Type Enzyme ◽  
Structural Dynamic ◽  
Mitochondrial Atp Synthase

Background: Neonatal Encephalopathy (NE) is a mitochondrial ATP synthase (mATPase) disease, which results in the death of infants. The case presented here is reportedly caused by complex V deficiency as a result of mutation of Arginine to Cysteine at residue 329 in the mATPase. A recent breakthrough was the discovery of J147, which targets mATPase in the treatment of Alzheimer’s disease. Based on the concepts of computational target-based drug design, this study investigated the possibility of employing J147 as a viable candidate in the treatment of NE. Objective/Methods: The structural dynamic implications of this drug on the mutated enzyme are yet to be elucidated. Hence, integrative molecular dynamics simulations and thermodynamic calculations were employed to investigate the activity of J147 on the mutated enzyme in comparison to its already established inhibitory activity on the wild-type enzyme. Results: A correlated structural trend occurred between the wild-type and mutant systems whereby all the systems exhibited an overall conformational transition. Equal observations in favorable free binding energies further substantiated uniformity in the mobility, and residual fluctuation of the wild-type and mutant systems. The similarity in the binding landscape suggests that J147 could as well modulate mutant mATPase activity in addition to causing structural modifications in the wild-type enzyme. Conclusions: Findings suggest that J147 can stabilize the mutant protein and restore it to a similar structural state as the wild-type which depicts functionality. These details could be employed in drug design for potential drug resistance cases due to mATPase mutations that may present in the future.

scholarly journals Suppression of a Nuclear aep2 Mutation in Saccharomyces cerevisiae by a Base Substitution in the 5′-Untranslated Region of the Mitochondrial oli1 Gene Encoding Subunit 9 of ATP Synthase

Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1353-1363
Author(s):  
Timothy P Ellis ◽  
H Bruce Lukins ◽  
Phillip Nagley ◽  
Brian E Corner
Keyword(s):  
Atp Synthase ◽  
Protein Interactions ◽  
Untranslated Region ◽  
Mitochondrial Gene ◽  
Nuclear Gene ◽  
Base Substitution ◽  
Pcr Analysis ◽  
Temperature Sensitive ◽  
Mitochondrial Atp Synthase ◽  
Subunit 9

Abstract Mutations in the nuclear AEP2 gene of Saccharomyces generate greatly reduced levels of the mature form of mitochondrial oli1 mRNA, encoding subunit 9 of mitochondrial ATP synthase. A series of mutants was isolated in which the temperature-sensitive phenotype resulting from the aep2-ts1 mutation was suppressed. Three strains were classified as containing a mitochondrial suppressor: these lost the ability to suppress aep2-ts1 when their mitochondrial genome was replaced with wild-type mitochondrial DNA (mtDNA). Many other isolates were classified as containing dominant nuclear suppressors. The three mitochondrion-encoded suppressors were localized to the oli1 region of mtDNA using rho– genetic mapping techniques coupled with PCR analysis; DNA sequencing revealed, in each case, a T-to-C nucleotide transition in mtDNA 16 nucleotides upstream of the oli1 reading frame. It is inferred that the suppressing mutation in the 5′ untranslated region of oli1 mRNA restores subunit 9 biosynthesis by accommodating the modified structure of Aep2p generated by the aep2-ts1 mutation (shown here to cause the substitution of proline for leucine at residue 413 of Aep2p). This mode of mitochondrial suppression is contrasted with that mediated by heteroplasmic rearranged rho– mtDNA genomes bypassing the participation of a nuclear gene product in expression of a particular mitochondrial gene. In the present study, direct RNA-protein interactions are likely to form the basis of suppression.

scholarly journals Mitochondrial ATP synthase disorders: Molecular mechanisms and the quest for curative therapeutic approaches

2009 ◽  
Vol 1793 (1) ◽  
pp. 186-199 ◽  
Author(s):  
Roza Kucharczyk ◽  
Michael Zick ◽  
Maïlis Bietenhader ◽  
Malgorzata Rak ◽  
Elodie Couplan ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Molecular Mechanisms ◽  
Therapeutic Approaches ◽  
Mitochondrial Atp Synthase

scholarly journals TMEM70 and TMEM242 help to assemble the rotor ring of human ATP synthase and interact with assembly factors for complex I

2021 ◽  
Vol 118 (13) ◽  
pp. e2100558118
Author(s):  
Joe Carroll ◽  
Jiuya He ◽  
Shujing Ding ◽  
Ian M. Fearnley ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Complex I ◽  
Transmembrane Protein ◽  
Mitochondrial Gene ◽  
Nuclear Gene ◽  
Gene Products ◽  
Mitochondrial Atp Synthase ◽  
Complex I Assembly ◽  
The Impact ◽  
Enzyme Complexes

Human mitochondrial ATP synthase is a molecular machine with a rotary action bound in the inner organellar membranes. Turning of the rotor, driven by a proton motive force, provides energy to make ATP from ADP and phosphate. Among the 29 component proteins of 18 kinds, ATP6 and ATP8 are mitochondrial gene products, and the rest are nuclear gene products that are imported into the organelle. The ATP synthase is assembled from them via intermediate modules representing the main structural elements of the enzyme. One such module is the c8-ring, which provides the membrane sector of the enzyme’s rotor, and its assembly is influenced by another transmembrane (TMEM) protein, TMEM70. We have shown that subunit c interacts with TMEM70 and another hitherto unidentified mitochondrial transmembrane protein, TMEM242. Deletion of TMEM242, similar to deletion of TMEM70, affects but does not completely eliminate the assembly of ATP synthase, and to a lesser degree the assembly of respiratory enzyme complexes I, III, and IV. Deletion of TMEM70 and TMEM242 together prevents assembly of ATP synthase and the impact on complex I is enhanced. Removal of TMEM242, but not of TMEM70, also affects the introduction of subunits ATP6, ATP8, j, and k into the enzyme. TMEM70 and TMEM242 interact with the mitochondrial complex I assembly (the MCIA) complex that supports assembly of the membrane arm of complex I. The interactions of TMEM70 and TMEM242 with MCIA could be part of either the assembly of ATP synthase and complex I or the regulation of their levels.

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