Functional analysis of WASP and Las17p using Saccharomyces cerevisiae las17Δ cells

Abstract

Wiskott Aldrich Syndrome (WAS) is a genetic disease caused by recessive mutations in the gene encoding the Wiskott Aldrich Syndrome protein (WASP). Patients suffering from WAS exhibit a variety of symptoms ranging from thrombocytopenia, eczema and immune disorders. WASP belongs to a family of proteins whose members include WASP, N-WASP, WAVEI-3 and Lasl7p. WASP has a WH1 domain at the N-terminus and the Arp213 complex activating VCA domain at the C-terminus. WASP is expressed predominantly in hematopoietic cells and is involved in integrating extracellular signals and regulating actin cytoskeleton. Lasl7p is the S. cerevisiae ortholog of mammalian WASP and has a similar domain structure as that of WASP. Deletion or mutation in the gene encoding Lasl7p makes the yeast cells inviable at restrictive temperatures and also causes defects in endocytosis and actin patch polarization at all temperatures.