Mutation of Signal Transducer and Activator of Transcription 5 (STAT5) Binding Sites Decreases Milk Allergen αS1-Casein Content in Goat Mammary Epithelial Cells

Abstract

αS1-Casein (encoded by the CSN1S1 gene) is associated with food allergy more than other milk protein components. Milk allergy caused by αS1-casein is derived from cow milk, goat milk and other ruminant milk. However, little is known about the transcription regulation of αS1-casein synthesis in dairy goats. This study aimed to investigate the regulatory roles of signal transducer and activator of transcription 5 (STAT5) on αS1-casein in goat mammary epithelial cells (GMEC). Deletion analysis showed that the core promoter region of CSN1S1 was located at −110 to −18 bp upstream of transcription start site, which contained two putative STAT5 binding sites (gamma-interferon activation site, GAS). Overexpression of STAT5a gene upregulated the mRNA level and the promoter activity of the CSN1S1 gene, and STAT5 inhibitor decreased phosphorylated STAT5 in the nucleus and CSN1S1 transcription activity. Further, GAS site-directed mutagenesis and chromatin immunoprecipitation (ChIP) assays revealed that GAS1 and GAS2 sites in the CSN1S1 promoter core region were binding sites of STAT5. Taken together, STAT5 directly regulates CSN1S1 transcription by GAS1 and GAS2 sites in GMEC, and the mutation of STAT5 binding sites could downregulate CSN1S1 expression and decrease αS1-casein synthesis, which provide the novel strategy for reducing the allergic potential of goat milk and improving milk quality in ruminants.

Enhancement of PPARα-Inhibited Leucine Metabolism-Stimulated β-Casein Synthesis and Fatty Acid Synthesis in Primary Bovine Mammary Epithelial Cells

“…CHIP-PCR was performed as described previously . Briefly, the Chip assays were conducted using a commercial kit (P2048, Beyotime, China).…”

“…CHIP-PCR was performed as described previously. 24 Briefly, the Chip assays were conducted using a commercial kit (P2048, Beyotime, China). BEMCs were collected and cross-linked with 1% formaldehyde at 37 °C for 10 min, followed by cold PBS containing protease inhibitor.…”

Associação entre polimorfismos de genes do eixo somatotrópico e eficiência reprodutiva de fêmeas bovinas: revisão de literatura

“…Os genes que codificam o GH e o IGF-I são os que compõem o eixo somatotrópico, assim como os receptores e diversas proteínas sinalizadoras presentes nas células, como o transdutor de sinal e ativador 5A (STAT5A), por este motivo o eixo somatotrópico se destaca como principal regulador tanto da fisiologia reprodutiva quanto do metabolismo dos mamíferos (17) . Nesses genes, o polimorfismo tem relação direta e indireta com o fenótipo, principalmente em relação à composição e síntese do leite (22) , propriedades da produção de carne e de carcaça (23) e atividades reprodutivas (24) .…”

Association between somatotropic axis gene polymorphisms and reproductive efficiency of bovine females: a review

“…The genes that encode GH and IGF-I form the somatotropic axis, along with the related receptors and several signaling proteins present in cells, such as signal transducer and activator 5A (STAT5A); therefore, the somatotropic axis is the main regulator of both reproductive physiology and mammalian metabolism (17) . Polymorphism is directly and indirectly related to the phenotype in these genes, mainly in relation to milk composition and synthesis (22) , meat and carcass production properties (23) and reproductive activities (24) .…”