WASP17

WASP17 is a protein-coding gene that encodes a member of the Wiskott‑Aldrich syndrome protein (WASP) family. The protein participates in the regulation of the actin cytoskeleton by activating the ARP2/3 complex, thereby promoting actin nucleation and polymerization. WASP17 contains the conserved domains typical of the WASP family: an N‑terminal profilin-binding region, a central VCA (WH2–linker–C‑inhibitory) domain, and a proline‑rich linker that mediates protein–protein interactions. The VCA domain binds G‑actin monomers and the ARP2/3 complex, while the proline‑rich region recruits SH3‑domain containing partners such as cortactin and dynamin.

The WASP17 gene is located on the long arm of human chromosome 15 (15q15.1). Transcription of the gene is driven by a promoter containing binding sites for transcription factors relevant to immune cell differentiation and neuronal development. mRNA is detected in a wide range of tissues, with comparatively higher expression in leukocytes, the brain, and placenta. The protein is thus implicated in both hematopoietic cell signalling and neuronal function.

Although only a few pathogenic variants have been reported, in vitro studies indicate that loss‑of‑function mutations reduce actin polymerization in immune cells, leading to defects in phagocytosis and cell migration. Rare cases of autosomal recessive immunodeficiency exhibiting impaired T‑cell activation have been associated with deleterious WASP17 variants, suggesting a potential but still under‑characterised role in the immune response.

Research on WASP17 is ongoing, with recent investigations focusing on its interaction with small GTPases such as CDC42 and RhoA, and its participation in the formation of podosome‑like structures in fibroblasts. Further studies are required to clarify its contribution to developmental biology and to determine whether it functions redundantly with other WASP family members in actin remodeling.