microtubule substrates than in free α/β-tubulin dimers. This is because once the ATAT1 is in the microtubule lumen, it diffuses freely and it has a high effective substrate concentration. Biological functions Formation of the hippocampus ATAT1 has an important role in the formation of the hippocampus, as it has been found that mice lacking ATAT1 possess a deficient tubulin acetylation and a bulge in the dentate gyrus. Response to stress and signaling pathways Tubulin acetylation by ATAT1 has been shown to be elevated by the cell exposure to UV irradiation, as well as its exposure to chemicals, such H2O2 or NaCl. Tubulin acetylation is one of the signaling pathways for Na+ and K+-ATPase activity. Autophagy Tubulin acetylation is also involved in regulating autophagy. It is required for fusion of autophagosomes with lysosomes. When there is a nutrient deprivation, starvation-induced tubulin hyperacetylation is required for autophagy activation. This is a way activated when the cell is under stress. Neuronal migration and maturation α-tubulin is a target of the Elongator complex and in the regulation of its acetylation underlies the maturation of cortical projection neurons. Sperm flagellar function Acetylation of the microtubules is required for normal sperm flagellar function. ATAT1 suppression in mice causes diminished sperm motility and male infertility. Cell migration Stable microtubules are involved in cell migration processes. Those microtubules need their acetylation. Thus, the ATAT1 enzyme is important in cell migration. Embryo development ATAT1 is quite important in embryo development in Zebrafish. Some authors consider that it may also be critical in embryo development in mammals. Ciliogenesis ATAT 1 plays an important role in the formation of cilia. It is actually being studied that ciliogenesis can have an effect in the development of handedness in homo sapiens. Moreover, Alpha-tubulin N-acetyltransferase is also essential to make sure that the primary cilium assembly can function in a state of normal kinetics. Promotes an efficient mechanosensation in C.elegans Intracellular location and associated functions Scientific background In 2010, there was discovered the existence of an α-tubuline N-acetyltransferase, not only in Tetrahymena and Caenorhabditis elegans, but also in mammalian. Additionally, two research groups generated ATAT1-knockout mice, which occasioned mice with a lack of acetylation in many tissues. However, its intracellular distribution was still unclear. Recent discoveries In order to discover the intracellular location of α-tubulin N-acetyltransferase and some of its functions, it was used a microscopy technique, called immunohistochemistry, which allows the differentiation of