The transcription factor STAT5 is critical for peripheral NK-cell survival, proliferation, and cytotoxic function. STAT5 refers to two highly related proteins, STAT5A and STAT5B. In this study, we verified the importance of STAT5A isoform for NK cells. We characterized an incidental chemically induced W484G mutation in the Stat5a gene and found that this mutation was associated with a reduction of STAT5A protein expression. Closer examination of NK-cell subsets from Stat5a mutant mice showed marked reductions in NK-cell number and maturation. IL-15 treatment of Stat5a mutant NK cells exhibited defective induction of both STAT5 and mTOR signaling pathways and reduced expression of granzyme B and IFN-γ. Finally, we observed that Stat5a mutant mice revealed more tumor growth upon injection of RMA-S tumor cell line. Overall, our results demonstrate that the W484G mutation in the linker domain of STAT5A is sufficient to compromise STAT5A function in NK-cell homeostasis, responsiveness, and tumoricidal function.
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http://dx.doi.org/10.1038/s41435-019-0088-6 | DOI Listing |
Int J Mol Sci
September 2024
Department of Pediatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Activating mutations plays a crucial role in leukemogenesis, but identifying the optimal candidates for inhibitor therapy remains controversial. This study aims to explore the impacts of mutations in pediatric acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) and to compare the mutation profiles between the two types to inspire the targeted application of inhibitors. We retrospectively analyzed 243 ALL and 62 AML cases, grouping them into -mutant and wild-type categories, respectively.
View Article and Find Full Text PDFNat Commun
August 2024
Laboratory of Molecular Immunology and Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892-1674, USA.
Cytokine-mediated STAT5 protein activation is vital for lymphocyte development and function. In vitro tyrosine phosphorylation of a C-terminal tyrosine is critical for activation of STAT5A and STAT5B; however, the importance of STAT5 tyrosine phosphorylation in vivo has not been assessed. Here we generate Stat5a and Stat5b tyrosine-to-phenylalanine mutant knockin mice and find they have greatly reduced CD8 T-cell numbers and profoundly diminished IL-2-induced proliferation of these cells, and this correlates with reduced induction of Myc, pRB, a range of cyclins and CDKs, and a partial G1→S phase-transition block.
View Article and Find Full Text PDFPLoS Genet
October 2023
Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, United States of America.
Retinal Müller glia (MG) can act as stem-like cells to generate new neurons in both zebrafish and mice. In zebrafish, retinal regeneration is innate and robust, resulting in the replacement of lost neurons and restoration of visual function. In mice, exogenous stimulation of MG is required to reveal a dormant and, to date, limited regenerative capacity.
View Article and Find Full Text PDFMethods Mol Biol
September 2023
Institute of Organic Chemistry, Leipzig University, Leipzig, Germany.
Fluorescence polarization (FP) assays can be used to identify small-molecule inhibitors that bind to SH2 domain-containing proteins. We have developed FP assays by which to identify inhibitors of the SH2 domains of the two closely-related transcription factors STAT5a and STAT5b. Point mutation of selected amino acids in the putative binding site of the protein is a valuable tool by which to gain insight into the molecular mechanism of binding.
View Article and Find Full Text PDFFront Mol Biosci
June 2022
Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Polokwane, South Africa.
Current lung cancer treatment strategies are ineffective, and lung cancer cases continue to soar; thus, novel anticancer drugs and targets are needed, and medicinal plants are promising to offer better alternatives. This study was aimed at analysing two splice variants during the potential anticancer activities of () methanol and water extracts against different human lung cancer cell lines of varying mutation status, and these included mutant H1573 and mutant H1437 and -wild type (A549) cells. The anticancer activities of the extracts were assessed by establishing the cytotoxic effect and the apoptosis-inducing capacity of these extracts, using the MTT assay and Annexin V analysis, respectively, with the latter confirmed using fluorescence microscopy.
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