Nck-associated protein 1 is part of lamellipodial complex that controls Rac-dependent actin remodeling [, ]. It associates preferentially with the first SH3 domain of Nck and is a component of the WAVE2 complex composed of ABI1, CYFIP1/SRA1, NCKAP1/NAP1 and WASF2/WAVE2. It is also a component of the WAVE1 complex composed of ABI2, CYFIP2, C3orf10/HSPC300, NCKAP1 and WASF1/WAVE1. CYFIP2 binds to activated RAC1 which causes the complex to dissociate, releasing activated WASF1. The complex can also be activated by NCK1. Expression of this protein was found to be markedly reduced in patients with Alzheimer's disease [].
This entry includes cytoplasmic fragile X messenger ribonucleoprotein 1-interacting proteins from humans and their homologues, such as Sra-1 (specifically Rac1-associated protein 1) from Drosophila and PIROGI from Arabidopsis. In humans, there are two members, CYFIP1 and CYFIP2. They both interact with FMRP (Fragile X messenger ribonucleoprotein 1), which is responsible for pathologic manifestations in the Fragile X Syndrome. CYFIP1 interacts with the small GTPase Rac1 [, ]. CYFIP1 represses cap-dependent translation of mRNA by interacting with the initiation factor eIF4E []. CYFIP1 and CYFIP2 are part of the Wiskott-Aldrich syndrome protein-family verprolin-homologous protein (WAVE) complex that regulates actin polymerization at synapses []. Drosophila Sra-1 interacts with the Kette and Wasp. It is required for neuronal and bristle development in Drosophila []. PIROGI is part of a WAVE complex that activates the ARP2/3 complex and is Involved in regulation of actin organization [].
