A Kinetic Model for Compound Heterozygous Pathogenic Variants in Tyrosyl-tRNA Synthetase Gene YARS2-Associated Neonatal Phenotype.

Human genetic disorders are often caused by mutations of compound heterozygosity, where each allele of the mutant gene harbors a different genetic lesion. However, studies of such mutations are hampered, due to the lack of an appropriate model. Here we describe a kinetic model of compound heterozygous variants in an obligate enzyme dimer that contains one mutation in one monomer and the other mutation in the second monomer.

Synthesis of Stably Charged Arg-tRNA for Structural Analysis.

Posttranslational protein arginylation catalyzed by arginyl transferases is a mechanism to regulate multiple physiological processes. This protein arginylation reaction uses a charged Arg-tRNA as the donor of arginine (Arg). The inherent instability of the ester linkage of the arginyl group to the tRNA, which is sensitive to hydrolysis at the physiological pH, makes it difficult to obtain structural information on how the arginyl transfer reaction is catalyzed.

tRNA methylation resolves codon usage bias at the limit of cell viability.

Codon usage of each genome is closely correlated with the abundance of tRNA isoacceptors. How codon usage bias is resolved by tRNA post-transcriptional modifications is largely unknown. Here we demonstrate that the N-methylation of guanosine at position 37 (mG37) on the 3'-side of the anticodon, while not directly responsible for reading of codons, is a neutralizer that resolves differential decoding of proline codons.

Landscape of the complete RNA chemical modifications in the human 80S ribosome.

During ribosome biogenesis, ribosomal RNAs acquire various chemical modifications that ensure the fidelity of translation, and dysregulation of the modification processes can cause proteome changes as observed in cancer and inherited human disorders. Here, we report the complete chemical modifications of all RNAs of the human 80S ribosome as determined with quantitative mass spectrometry. We assigned 228 sites with 14 different post-transcriptional modifications, most of which are located in functional regions of the ribosome.

The complete chemical structure of Saccharomyces cerevisiae rRNA: partial pseudouridylation of U2345 in 25S rRNA by snoRNA snR9.

We present the complete chemical structures of the rRNAs from the eukaryotic model organism, Saccharomyces cerevisiae The final structures, as determined with mass spectrometry-based methodology that includes a stable isotope-labelled, non-modified reference RNA, contain 112 sites with 12 different post-transcriptional modifications, including a previously unidentified pseudouridine at position 2345 in 25S rRNA. Quantitative mass spectrometry-based stoichiometric analysis of the different modifications at each site indicated that 94 sites were almost fully modified, whereas the remaining 18 sites were modified to a lesser extent. Superimposed three-dimensional modification maps for S.

The C-terminal cytoplasmic tail of hedgehog receptor Patched1 is a platform for E3 ubiquitin ligase complexes.

The Sonic hedgehog (Shh) signaling pathway plays a crucial role in cell proliferation and differentiation via Patched1 (Ptc1), a 12-pass transmembrane receptor protein. The C-terminal cytoplasmic tail of Ptc1 can be cleaved to release the 7th intracellular domain (ICD7), whose function is still unclear. In this study, we found that the ICD7 fragment of Ptc1 associates with polyubiquitinated species.