ABSTRACT
Gas7 (growth arrest-şpecific gene 7) has recently been classified to be a member o f the Pombe Cdc 15 homology (PCH) family and belongs to the proline, serine, threonine-rich phosphatase interacting protein (PSTPIP) subfamily.1,2 Most PCH proteins share a similar domain architecture, which is composed o f an N-terminal Fes/CIP4 homology (FCH) domain, a coiled-coil (CC) region and one or two Src homology (SH3) domains.1 The PSTPIPs, a subfamily o f the PCH proteins, are tyrosine-phosphorylated proteins involved in the organization o f the cytoskeleton and are substrates for the PEST-type protein tyrosine phosphatases.3,4 Among the PSTPIPs, PSTPIP 1 interacts with neural Wiskott-Aldrich syndrome protein (N-WASP) and the interaction is regulated by phosphorylation on two tyrosine residues in the SH3 domain.5 In addition, another member o f the PSTPIP subfamily, PSTPIP2, has been proven to direcdy bind and crosslink actin to induce filopodia formation.6,7 This chapter will present the identified characteristics o f mouse Gas7 as well as its physiological roles in relation to the PCH proteins, especially the PSTPIP family.
