A model organism pipeline provides insight into the clinical heterogeneity of TARS1 loss-of-function variants.

Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed, essential enzymes that complete the first step of protein translation: ligation of amino acids to cognate tRNAs. Genes encoding ARSs have been implicated in myriad dominant and recessive phenotypes, the latter often affecting multiple tissues but with frequent involvement of the central and peripheral nervous systems, liver, and lungs. Threonyl-tRNA synthetase (TARS1) encodes the enzyme that ligates threonine to tRNA in the cytoplasm.

Muscle stem cells as immunomodulator during regeneration.

The skeletal muscle is well known for its remarkable ability to regenerate after injuries. The regeneration is a complex and dynamic process that involves muscle stem cells (also called muscle satellite cells, MuSCs), fibro-adipogenic progenitors (FAPs), immune cells, and other muscle-resident cell populations. The MuSCs are the myogenic cell populaiton that contribute nuclei directly to the regenerated myofibers, while the other cell types collaboratively establish a microenvironment that facilitates myogenesis of MuSCs.

PRMT5 mediates FoxO1 methylation and subcellular localization to regulate lipophagy in myogenic progenitors.

Development is regulated by various factors, including protein methylation status. While PRMT5 is well known for its roles in oncogenesis by mediating symmetric di-methylation of arginine, its role in normal development remains elusive. Using Myod1 to drive Prmt5 knockout in embryonic myoblasts (Prmt5), we dissected the role of PRMT5 in myogenesis.

Sox11 is enriched in myogenic progenitors but dispensable for development and regeneration of the skeletal muscle.

Transcription factors (TFs) play key roles in regulating differentiation and function of stem cells, including muscle satellite cells (MuSCs), a resident stem cell population responsible for postnatal regeneration of the skeletal muscle. Sox11 belongs to the Sry-related HMG-box (SOX) family of TFs that play diverse roles in stem cell behavior and tissue specification. Analysis of single-cell RNA-sequencing (scRNA-seq) datasets identify a specific enrichment of Sox11 mRNA in differentiating but not quiescent MuSCs.