Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
HGG Adv ; : 100324, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38956874

ABSTRACT

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 tRNATHR in the cytoplasm. To date, TARS1 variants have been implicated in a recessive brittle hair phenotype. To better understand TARS1-related recessive phenotypes, we engineered three TARS1 missense variants at conserved residues and studied these variants in S. cerevisiae and C. elegans models. This revealed two loss-of-function variants, including one hypomorphic allele (R433H). We next used R433H to study the effects of partial loss of TARS1 function in a compound heterozygous mouse model (R432H/null). This model presents with phenotypes reminiscent of patients with TARS1 variants and with distinct lung and skin defects. This study expands the potential clinical heterogeneity of TARS1-related recessive disease, which should guide future clinical and genetic evaluations of patient populations.

2.
bioRxiv ; 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38979321

ABSTRACT

Alanyl-tRNA synthetase 1 ( AARS1 ) encodes the enzyme that ligates tRNA molecules to alanine in the cytoplasm, which is required for protein translation. Variants in AARS1 have been implicated in early-onset, multi-system recessive phenotypes and in later-onset dominant peripheral neuropathy; to date, no single variant has been associated with both dominant and recessive diseases raising questions about shared mechanisms between the two inheritance patterns. AARS1 variants associated with recessive disease are predicted to result in null or hypomorphic alleles and this has been demonstrated, in part, via yeast complementation assays. However, pathogenic alleles have not been assessed in a side-by-side manner to carefully scrutinize the strengths and limitations of this model system. To address this, we employed a humanized yeast model to evaluate the functional consequences of all AARS1 missense variants reported in recessive disease. The majority of variants showed variable loss-of-function effects, ranging from no growth to significantly reduced growth. These data deem yeast a reliable model to test the functional consequences of human AARS1 variants; however, our data indicate that this model is prone to false-negative results and is not informative for genotype-phenotype studies. We next tested missense variants associated with no growth for dominant-negative effects. Interestingly, K81T AARS1 , a variant implicated in recessive disease, demonstrated loss-of-function and dominant-negative effects, indicating that certain AARS1 variants may be capable of causing both dominant and recessive disease phenotypes.

3.
bioRxiv ; 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38585737

ABSTRACT

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 system, liver, and lungs. Threonyl-tRNA synthetase (TARS1) encodes the enzyme that ligates threonine to tRNATHR in the cytoplasm. To date, TARS1 variants have been implicated in a recessive brittle hair phenotype. To better understand TARS1-related recessive phenotypes, we engineered three TARS1 missense mutations predicted to cause a loss-of-function effect and studied these variants in yeast and worm models. This revealed two loss-of-function mutations, including one hypomorphic allele (R433H). We next used R433H to study the effects of partial loss of TARS1 function in a compound heterozygous mouse model (R433H/null). This model presents with phenotypes reminiscent of patients with TARS1 variants and with distinct lung and skin defects. This study expands the potential clinical heterogeneity of TARS1-related recessive disease, which should guide future clinical and genetic evaluations of patient populations.

SELECTION OF CITATIONS
SEARCH DETAIL
...