STIL

Description

The STIL (STIL centriolar assembly protein) is a protein-coding gene located on chromosome 1.

STIL (SCL-interrupting locus protein) is a protein essential for centriole biogenesis and plays a role in the mitotic spindle checkpoint. It is present in many cell types and is phosphorylated during mitosis and in response to spindle checkpoint activation. STIL interacts with mitotic regulators and is required for efficient spindle checkpoint activation. It is proposed to regulate Cdc2 kinase activity during spindle checkpoint arrest. Deletions fusing STIL with the adjacent locus are common in T cell leukemias, likely due to illegitimate recombination events. Multiple transcript variants encoding different isoforms have been found. STIL expression is linked to an increased mitotic index and cancer development, and is associated with Hedgehog family-mediated signaling events.

STIL is an immediate-early gene that plays a crucial role in embryonic development, cellular growth, and proliferation. Its long-term silencing negatively impacts cell survival, cell cycle distribution, and reduces CDK1 activity, linked to decreased phosphorylation of CDK1. STIL acts as a positive regulator of the sonic hedgehog pathway, functioning downstream of PTCH1. It is essential for regulating centriole duplication, including the initiation of procentriole formation and proper mitotic progression. During procentriole formation, STIL ensures the correct loading of SASS6 and CENPJ at the base of the procentriole, initiating its assembly. In complex with STIL, PLK4-driven cytoskeletal rearrangements and directional cell motility are modulated.

STIL is also known as MCPH7, SIL.

Associated Diseases

• Microcephaly 7, primary, autosomal recessive
• Septopreoptic holoprosencephaly
• Semilobar holoprosencephaly
• Autosomal recessive primary microcephaly
• Midline interhemispheric variant of holoprosencephaly
• Alobar holoprosencephaly
• Lobar holoprosencephaly