An amino-terminal methionine corresponding to a recombinant AUG initiation codon sometimes affects the functions of proteins. To test the performance of translation mediated by a dicistroviral internal ribosome entry site (IRES), which initiates protein synthesis with elongator tRNAs, we optimized the conditions for cell-free translation. Although the IRES is 188 nucleotides long, a further 50 nucleotides of the upstream sequence stabilized translation efficiency. Optimal ion concentrations were affected by the sequences of the constructs. In a wheat-germ system, IRES-mediated translation produced 78 microg/ml of firefly luciferase from the AUG-deleted sequence, suggesting that dicistroviral IRESs will be able to yield polypeptides with a specific N-terminal amino acid other than methionine.
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http://dx.doi.org/10.1093/jb/mvh167 | DOI Listing |
Endocrinology
August 2023
Department of Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
In this review, we provide the status of research on vasoactive intestinal peptide (VIP) and oxytocin, typical C-terminal α-amidated peptide hormones, including their precursor protein structures, processing and C-terminal α-amidation, and the recently identified mechanisms of regulation of oxytocin secretion and its transportation through the blood brain barrier. More than half of neural and endocrine peptides, such as VIP and oxytocin, have the α-amide structure at their C-terminus, which is essential for biological activities. We have studied the synthesis and function of C-terminal α-amidated peptides, including VIP and oxytocin, since the 1980s.
View Article and Find Full Text PDFMethods Mol Biol
December 2022
Max-Delbrück-Center for Molecular Medicine in the Helmholz Association, Berlin Buch, Germany.
The traditional textbook describes ubiquitylation as the conjugation of ubiquitin to a target by forming a covalent bond connecting ubiquitin's carboxy-terminal glycine residue with an acceptor amino acid like lysine or amino-terminal methionine in the substrate protein. While this adequately depicts a significant fraction of cellular ubiquitylation processes, a growing number of ubiquitin modifications do not follow this rule. Recent data demonstrate that ubiquitin can also be efficiently attached to other amino acids, such as cysteine, serine, and threonine, via ester bonding.
View Article and Find Full Text PDFInt J Biol Macromol
December 2021
Department of Food Biotechnology, Institute of Agrochemistry and Food Technology (IATA-CSIC), Catedrático Agustín Escardino 7, 46980 Paterna, Valencia, Spain. Electronic address:
Copper (Cu) plays a key role as cofactor in the plant proteins participating in essential cellular processes, such as electron transport and free radical scavenging. Despite high-affinity Cu transporters (COPTs) being key participants in Cu homeostasis maintenance, very little is known about COPTs in tomato (Solanum lycopersicum) even though it is the most consumed fruit worldwide and this crop is susceptible to suboptimal Cu conditions. In this study, a six-member family of COPT (SlCOPT1-6) was identified and characterized.
View Article and Find Full Text PDFJ Mol Biol
November 2020
Vivet Therapeutics S.L., Pamplona, Spain; Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona 31008, Spain. Electronic address:
Protein lifespan is regulated by co-translational modification by several enzymes, including methionine aminopeptidases and N-alpha-aminoterminal acetyltransferases. The NatB enzymatic complex is an N-terminal acetyltransferase constituted by two subunits, NAA20 and NAA25, whose interaction is necessary to avoid NAA20 catalytic subunit degradation. We found that deletion of the first five amino acids of hNAA20 or fusion of a peptide to its amino terminal end abolishes its interaction with hNAA25.
View Article and Find Full Text PDFMetallomics
November 2020
Department of Bio-Analytical Chemistry, Faculty of Pharmacy, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo 202-8585, Japan.
Excessive zinc ion (Zn) release is induced in pathological situations and causes neuronal cell death. Previously, we have reported that copper ions (Cu) markedly exacerbated Zn-induced neuronal cell death by potentiating oxidative stress, the endoplasmic reticulum (ER) stress response, and the activation of the c-Jun amino-terminal kinase (JNK) signaling pathway. In contrast, selenium (Se), an essential trace element, and amino acids containing selenium (such as seleno-l-methionine) have been reported to inhibit stress-induced neuronal cell death and oxidative stress.
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