AP4S1

Ideogram human chromosome 14

AP4S1

AP4S1 is a gene that encodes the AP-4 complex subunit sigma-1 protein in humans. This protein is a subunit of the AP-4 complex, which is involved in intracellular protein trafficking. Mutations in the AP4S1 gene have been associated with a rare neurodevelopmental disorder known as spastic paraplegia type 52 (SPG52).

Function

The AP-4 complex is a heterotetrameric protein complex that plays a crucial role in the sorting and trafficking of proteins within cells. The AP-4 complex consists of four subunits: beta-4, mu-4, sigma-4, and epsilon-4. The sigma-1 subunit, encoded by the AP4S1 gene, is responsible for recognizing and binding to specific cargo proteins to facilitate their transport within the cell.

Clinical Significance

Mutations in the AP4S1 gene have been linked to spastic paraplegia type 52 (SPG52), a rare autosomal recessive disorder characterized by progressive spasticity and weakness in the lower limbs. Individuals with SPG52 may also experience intellectual disability, speech difficulties, and other neurological symptoms. The exact mechanisms by which mutations in AP4S1 lead to the development of SPG52 are not fully understood.

Research

Research into the function of the AP-4 complex and the role of the AP4S1 gene in cellular trafficking is ongoing. Studies investigating the molecular pathways disrupted by mutations in AP4S1 aim to uncover potential therapeutic targets for the treatment of SPG52 and other related disorders.

See also

• AP-4 complex
• Spastic paraplegia type 52