Escherichia coli leucyl/phenylalanyl-tRNA protein transferase catalyzes the tRNA-dependent post-translational addition of amino acids onto the N-terminus of a protein polypeptide substrate. Based on biochemical and structural studies, the current tRNA recognition model by L/F transferase involves the identity of the 3' aminoacyl adenosine and the sequence-independent docking of the D-stem of an aminoacyl-tRNA to the positively charged cluster on L/F transferase. However, this model does not explain the isoacceptor preference observed 40 yr ago. Using in vitro-transcribed tRNA and quantitative MALDI-ToF MS enzyme activity assays, we have confirmed that, indeed, there is a strong preference for the most abundant leucyl-tRNA, tRNA(Leu) (anticodon 5'-CAG-3') isoacceptor for L/F transferase activity. We further investigate the molecular mechanism for this preference using hybrid tRNA constructs. We identified two independent sequence elements in the acceptor stem of tRNA(Leu) (CAG)-a G₃:C₇₀ base pair and a set of 4 nt (C₇₂, A₄:U₆₉, C₆₈)-that are important for the optimal binding and catalysis by L/F transferase. This maps a more specific, sequence-dependent tRNA recognition model of L/F transferase than previously proposed.
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http://dx.doi.org/10.1261/rna.044529.114 | DOI Listing |
Cancer Res Commun
January 2025
Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California.
Eliminating "persisters" before relapse is crucial for achieving durable treatment efficacy. This study provides a rationale for developing PRMT1-selective inhibitors to target cancer persisters and achieve more durable outcomes in oncogene-targeting therapies.
View Article and Find Full Text PDFNeurology
January 2025
From the U763 (P.M., N.M., I.A., T.S., J.J.V.), Centro de Investigación Biomédica en Red Enfermedades Raras (CIBERER), Madrid; Neuromuscular Research Group (P.M., I.P.C., N.M., I.A., L.F., R.V., T.S., J.J.V.), IIS La Fe; Neuromuscular Referral Center ERN-EURO-NMD (I.P.C.), Neuropediatric Department, UIP La Fe Hospital; Neuromuscular Referral Center ERN-EURO-NMD (N.M., T.S.), Neurology Department, UIP La Fe Hospital, Valencia; and Department of Medicine (N.M., T.S., J.J.V.), Universitat de Valencia, Spain.
bioRxiv
November 2024
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, USA.
Clin Transl Sci
November 2024
Morcos Pharmaceutical Consulting, LLC, Marlboro, New Jersey, USA.
Most cancers and neoplastic progenitor cells have elevated telomerase activity and preservation of telomeres that promote cellular immortality, making telomerase a rational target for the treatment of cancer. Imetelstat is a first-in-class, 13-mer oligonucleotide that binds with high affinity to the template region of the RNA component of human telomerase and acts as a competitive inhibitor of human telomerase enzymatic activity. Pharmacokinetics, pharmacodynamics, exposure-response analyses, efficacy, and safety of imetelstat have been evaluated in vitro, in vivo, and clinically in solid tumor and hematologic malignancies, including lower-risk myelodysplastic syndromes (LR-MDS) and myeloproliferative neoplasms.
View Article and Find Full Text PDFNat Commun
October 2024
Department of Genetics, Institut Curie, 75005, Paris, France.
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