Protein synthesis involves two methionine-isoaccepting tRNAs, an initiator and an elongator. In eubacteria, mitochondria, and chloroplasts, the addition of a formyl group gives its full functional identity to initiator Met-tRNA(Met). In Escherichia coli, it has been shown that the specific action of methionyl-tRNA transformylase on Met-tRNA(f)(Met) mainly involves a set of nucleotides in the acceptor stem, particularly a C(1)A(72) mismatch. In animal mitochondria, only one tRNA(Met) species has yet been described. It is admitted that this species can engage itself either in initiation or elongation of translation, depending on the presence or absence of a formyl group. In the present study, we searched for the identity elements of tRNA(Met) that govern its formylation by bovine mitochondrial transformylase. The main conclusion is that the mitochondrial formylase preferentially recognizes the methionyl moiety of its tRNA substrate. Moreover, the relatively small importance of the tRNA acceptor stem in the recognition process accounts for the protection against formylation of the mitochondrial tRNAs that share with tRNA(Met) an A(1)U(72) motif.
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http://dx.doi.org/10.1074/jbc.M101007200 | DOI Listing |
Proc Natl Acad Sci U S A
November 2024
Department of Biology, University of Rochester, Rochester, NY 14627.
Within a cell, protein-bound methionines can be chemically or enzymatically oxidized, and subsequently reduced by methionine sulfoxide reductases (Msrs). Methionine oxidation can result in structural damage or be the basis of functional regulation of enzymes. In addition to participating in redox reactions, methionines play an important role as the initiator residue of translated proteins where they are commonly modified at their α-amine group by formylation or acetylation.
View Article and Find Full Text PDFAnimals (Basel)
July 2024
Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Boar sperm quality serves as an important indicator of reproductive efficiency, playing a direct role in enhancing the output of livestock production. It has been demonstrated that mitochondrial protein translation is present in sperm and plays a crucial role in regulating sperm motility, capacitation and in vitro fertilization rate. The present study aimed to determine whether methionine supplementation enhances mitochondrial translation in boar sperm, thereby improving sperm quality.
View Article and Find Full Text PDFCancer Sci
October 2024
Tumor Immunology Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Fukuoka, Japan.
Mitochondrial N-formylpeptides are released from damaged or dead cells to the extracellular spaces and cause inflammatory responses. The role of mitochondrial N-formylpeptides in aseptic systemic inflammatory response syndromes induced by trauma or cardiac surgery has been well investigated. However, there are no reports regarding the role of mitochondrial N-formylpeptides in cancer.
View Article and Find Full Text PDFCell
December 2023
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08544, USA. Electronic address:
Free Radic Biol Med
January 2024
Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China; MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, PR China. Electronic address:
While antibiotics are designed to target bacteria specifically, most are known to affect host cell physiology. Certain classes of antibiotics have been reported to have immunosuppressive effects, but the underlying mechanisms remain elusive. Here, we show that doxycycline, a ribosomal-targeting antibiotic, effectively inhibited both mitochondrial translation and nucleotide-binding domain and leucine-rich repeat-containing protein 3 (NLRP3) inflammasome-mediated caspase-1 activation and interleukin-1β (IL-1β) production in bone-marrow-derived macrophages (BMDMs).
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