ATP-citrate lyase (ACL) is essential for histone acetylation in mammalian cells. Histone acetylation, which regulates chromatin structure and gene expression, relies on acetyl-CoA, a molecule generated by ACL from citrate derived from glucose. ACL is required for increased histone acetylation in response to growth factors and during differentiation, and its activity is dependent on glucose availability. ACL-dependent production of acetyl-CoA is crucial for global histone acetylation under normal growth conditions, while AceCS1, a homologue of ACL in mammals, can also contribute, especially when acetate is available. ACL is localized in both the nucleus and cytoplasm, and its activity is necessary for the regulation of histone acetylation. Silencing ACL significantly reduces histone acetylation, while AceCS1 has a lesser effect. ACL-dependent acetyl-CoA production is not required for the acetylation of all cellular proteins, such as tubulin, suggesting that ACL's role is specifically linked to histone acetylation. ACL activity is also important for the regulation of gene expression during cellular processes such as mitogenic stimulation and adipocyte differentiation. ACL silencing reduces histone acetylation and affects the expression of genes involved in glucose metabolism, including the glucose transporter Glut4 and glycolytic enzymes. Acetate can rescue these effects, indicating that ACL and AceCS1 can compensate for each other under certain conditions. The regulation of histone acetylation by ACL is dependent on nutrient availability, particularly glucose. ACL silencing reduces glucose uptake and metabolism, leading to decreased histone acetylation and impaired adipocyte differentiation. However, the presence of acetate can restore these effects, highlighting the importance of ACL in linking metabolic state to histone acetylation and gene expression. In summary, ACL plays a critical role in determining the level of histone acetylation in mammalian cells, linking cellular metabolism to histone acetylation and gene expression. ACL-dependent acetyl-CoA production is essential for the regulation of histone acetylation during growth factor stimulation and adipocyte differentiation, and its activity is required to coordinate nuclear activity with cellular metabolic state. These findings suggest that ACL activity is a key regulator of histone acetylation, which is dynamically influenced by physiological changes in acetyl-CoA levels.ATP-citrate lyase (ACL) is essential for histone acetylation in mammalian cells. Histone acetylation, which regulates chromatin structure and gene expression, relies on acetyl-CoA, a molecule generated by ACL from citrate derived from glucose. ACL is required for increased histone acetylation in response to growth factors and during differentiation, and its activity is dependent on glucose availability. ACL-dependent production of acetyl-CoA is crucial for global histone acetylation under normal growth conditions, while AceCS1, a homologue of ACL in mammals, can also contribute, especially when acetate is available. ACL is localized in both the nucleus and cytoplasm, and its activity is necessary for the regulation of histone acetylation. Silencing ACL significantly reduces histone acetylation, while AceCS1 has a lesser effect. ACL-dependent acetyl-CoA production is not required for the acetylation of all cellular proteins, such as tubulin, suggesting that ACL's role is specifically linked to histone acetylation. ACL activity is also important for the regulation of gene expression during cellular processes such as mitogenic stimulation and adipocyte differentiation. ACL silencing reduces histone acetylation and affects the expression of genes involved in glucose metabolism, including the glucose transporter Glut4 and glycolytic enzymes. Acetate can rescue these effects, indicating that ACL and AceCS1 can compensate for each other under certain conditions. The regulation of histone acetylation by ACL is dependent on nutrient availability, particularly glucose. ACL silencing reduces glucose uptake and metabolism, leading to decreased histone acetylation and impaired adipocyte differentiation. However, the presence of acetate can restore these effects, highlighting the importance of ACL in linking metabolic state to histone acetylation and gene expression. In summary, ACL plays a critical role in determining the level of histone acetylation in mammalian cells, linking cellular metabolism to histone acetylation and gene expression. ACL-dependent acetyl-CoA production is essential for the regulation of histone acetylation during growth factor stimulation and adipocyte differentiation, and its activity is required to coordinate nuclear activity with cellular metabolic state. These findings suggest that ACL activity is a key regulator of histone acetylation, which is dynamically influenced by physiological changes in acetyl-CoA levels.