Knockout Mouse Studies Show That Mitochondrial CLPP Peptidase and CLPX Unfoldase Act in Matrix Condensates near IMM, as Fast Stress Response in Protein Assemblies for Transcript Processing, Translation, and Heme Production

Genes, Journal Year: 2024, Volume and Issue: 15(6), P. 694 - 694

Published: May 27, 2024

LONP1 is the principal AAA+ unfoldase and bulk protease in mitochondrial matrix, so its deletion causes embryonic lethality. The CLPX peptidase CLPP also act especially during stress periods, but their substrates are poorly defined. Mammalian triggers infertility, deafness, growth retardation, cGAS-STING-activated cytosolic innate immunity. mutations impair heme biosynthesis heavy metal homeostasis. conserved from bacteria to humans, despite secondary role proteolysis. Based on recent proteomic-metabolomic evidence knockout mice patient cells, we propose that acts phase-separated ribonucleoprotein granules multi-enzyme condensates as first-aid systems near inner membrane. Trimming within assemblies, rescues stalled processes mitoribosomes, RNA nucleoids, D-foci-mediated degradation of toxic double-stranded mtRNA/mtDNA. Unfolding condensates, maximizes PLP-dependent delta-transamination malformed nascent peptides. Overall, actions occur with multivalent or hydrophobic interactions, separated aqueous phase. Thus, CLPXP matrix compartment-selective, other peptidases: MPPs at precursor import pores, m-AAA i-AAA either IMM face, PARL IMM, OMA1/HTRA2 intermembrane space.

Language: Английский

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Vertebrates show coordinated elevated expression of mitochondrial and nuclear genes after birth: a conserved metabolic switch

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 25, 2024

Abstract Interactions between mitochondrial and nuclear factors are essential to life. Nevertheless, the importance of coordinated regulation mitochondrial-nuclear gene expression (CMNGE) changing physiological conditions is poorly understood, limited certain tissues organisms. We hypothesized that CMNGE important for development across vertebrates, hence will be conserved. As a first step, we analyzed >1400 RNA-seq experiments performed during embryo development, neonates adults vertebrate evolution. found conserved sharp elevation after birth CMNGE, including oxidative phosphorylation (OXPHOS) ribosome genes, in heart, hindbrain, forebrain kidney mammals, Gallus gallus lizard Anolis carolinensis . This was accompanied by elevated TCA cycle enzymes, reduction hypoxia response suggesting cross-tissue metabolic switch birth/hatching. Analysis ∼70 known regulators revealed consistently PGC-1a C/EBPB birth/hatching organisms tissues, thus highlighting them as candidate upon transition neonate. Analyses Danio rerio , Xenopus tropicalis Drosophila melanogaster prior hatching, coinciding with motor neurons. Lack such ancient pattern mammals chicken suggests it lost radiation terrestrial vertebrates. Taken together, our results suggest regulated embryogenesis birth, alludes which under strong selective constraints essential.

Language: Английский

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Transcription arrest induces formation of protective RNA granules in mitochondria

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 26, 2024

Abstract Mitochondrial gene expression regulation is required for the biogenesis of oxidative phosphorylation (OXPHOS) complexes, yet spatial organization mitochondrial RNAs (mt-RNAs) remains unknown. Here, we investigated distribution mt-RNAs during various cellular stresses using single-molecule RNA-FISH. We discovered that transcription inhibition leads to formation distinct RNA granules within mitochondria, which term granules. These structures differ from canonical (MRGs) and form in response multiple arrest conditions, including ethidium bromide treatment, specific polymerase, depletion SUV3 helicase. Inhibition appear serve a protective function, stabilizing certain mt-mRNAs prolonged inhibition. This phenomenon coincides with an imbalance OXPHOS complex expression, where mitochondrial-encoded transcripts decrease while nuclear-encoded subunits remain stable. found cells recover via resolving granules, restarting repopulating network hours. suggest may act as reservoir help overcome recovery arrest.

Language: Английский

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Engineering mtDNA Deletions by Reconstituting End-Joining in Human Mitochondria

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 17, 2024

Recent breakthroughs in the genetic manipulation of mitochondrial DNA (mtDNA) have enabled precise introduction base substitutions and effective removal genomes carrying harmful mutations. However, reconstitution mtDNA deletions responsible for severe myopathies age-related diseases has not yet been achieved human cells. Here, we developed a method to engineer specific cells by co-expressing end-joining (EJ) machinery targeted endonucleases. As proof-of-concept, used mito-EJ mito-ScaI generate panel clonal cell lines harboring ∼3.5 kb deletion with full spectrum heteroplasmy. Investigating these isogenic revealed critical threshold ∼75% deleted genomes, beyond which exhibited depletion OXPHOS proteins, metabolic disruption, impaired growth galactose-containing media. Single-cell multiomic analysis two distinct patterns nuclear gene deregulation response accumulation; one triggered at another progressively responding increasing In summary, co-expression programable nucleases provides powerful tool model disease-associated different types. Establishing large-scale varying levels heteroplasmy is valuable resource understanding impact on guiding development potential therapeutic strategies.

Language: Английский

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Wars1 downregulation in hepatocytes induces mitochondrial stress and disrupts metabolic homeostasis

Metabolism, Journal Year: 2024, Volume and Issue: 162, P. 156061 - 156061

Published: Nov. 7, 2024

Language: Английский

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