Somatic cell hybrids obtained from the fusion of human B lymphocytes and an asparagine synthetase-deficient Chinese hamster ovary cell line were isolated after growth in asparagine-free medium. The human and hamster forms of asparagine synthetase differ significantly in their rate of inactivation at 47.5 degrees C. The asparagine synthetase activity expressed in the hybrids was inactivated at 47.5 degrees C at the same rate as the human form of the enzyme. Karyotypic analysis and analysis for chromosome-specific enzyme markers showed that the structural gene for asparagine synthetase is located on chromosome 7 in humans. The heat-inactivation profile for asparagine synthetase in extracts of hybrids formed between human peripheral leukocytes and a hamster cell line expressing asparagine synthetase activity was intermediate between the two parental types when human chromosome 7 was present, but was identical to the hamster parent when chromosome 7 was absent.
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http://dx.doi.org/10.1007/BF01574256 | DOI Listing |
J Appl Microbiol
January 2025
School of Life Sciences, Qingdao Agricultural University, No.700 Changcheng Road, Chengyang District, Qingdao 266000, People's Republic of China.
Aims: The aim of this study was to evaluate the impact of the introduction of a phosphoribosylpyrophosphate synthetase (PRS) mutation into a plant growth-promoting strain of Methylorubrum on the enhancement of phyllosphere colonization, with the ultimate goal of improving plant growth and quality.
Methods And Results: A strain of Methylorubrum populi (named HS04) was isolated from the groundnut leaves and found to process the plant-promoting traits, including the ability to produce indole acetic acid, siderophore, 1-aminocyclopropane-1-carboxylate deaminase, and to fix nitrogen. The application via foliar spray significantly increased the fresh weight of cucumber seedlings cultivated in a standard growth chamber, with 43.
Proc Natl Acad Sci U S A
January 2025
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.
C-Terminal cyclic imides are posttranslational modifications that can arise from spontaneous intramolecular cleavage of asparagine or glutamine residues resulting in a form of irreversible protein damage. These protein damage events are recognized and removed by the E3 ligase substrate adapter cereblon (CRBN), indicating that these aging-related modifications may require cellular quality control mechanisms to prevent deleterious effects. However, the factors that determine protein or peptide susceptibility to C-terminal cyclic imide formation or their effect on protein stability have not been explored in detail.
View Article and Find Full Text PDFMol Med
January 2025
General Surgery Department, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, China.
Several members of the NIMA-related kinase (NEK) family have been implicated in tumor progression; however, the role and underlying mechanisms of NEK8 in gastric cancer (GC) remain unclear. This study revealed a significant upregulation of NEK8 in GC, identifying it as an independent prognostic marker in patients with GC. Consistent with these findings, NEK8 silencing substantially impeded GC aggressiveness both in vitro and in vivo, while its overexpression produced the opposite effect.
View Article and Find Full Text PDFCancer Lett
December 2024
Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, USA; Enzyme By Design Inc., Chicago, USA; Research Biologist, Biological Science Research and Development, Department of Veterans Affairs Medical Center, Chicago, IL, USA. Electronic address:
L-asparaginase (L-ASNase) is crucial in treating pediatric acute lymphoblastic leukemia (ALL), but its use is hampered by side effects from the immunogenicity and L-glutaminase (L-GLNase) co-activity of FDA-approved bacterial L-ASNases, often leading to treatment discontinuation and poor outcomes. The toxicity of these L-ASNases makes them especially challenging to use in adult cancer patients. To overcome these issues, we developed EBD-200, a humanized guinea pig L-ASNase with low Km and no L-GLNase activity, eliminating glutamine-related toxicity.
View Article and Find Full Text PDFJ Genet Genomics
December 2024
Hainan Key Laboratory of Tropical Oil Crops Biology/Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan 571339, China; Hainan Coconut International Joint Research Center, Wenchang, Hainan 571339, China. Electronic address:
Coconut (Cocos nucifera L.) is a key tropical economic tree valued for its fruit flavor, particularly 2-acetyl-1-pyrroline (2AP), a vital aroma metabolite. To enhance high-aromatic coconut breeding efforts, it is essential to deeply understand the hereditary factors governing the production of 2AP.
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