| Modification Notes |
Atrophin interacting proteins (AIP)s bind to atrophin-1 in the vicinity of the polyglutamine tract (1,2). The WW domain consists of 35-40 amino acids and is characterized by four well conserved aromatic residues, two of which are tryptophan (3-6). All five AIPs contain multiple WW domains and can be divided into two distinct classes (1). AIP1 and AIP3 (WWP3) are MAGUK-like multidomain proteins containing a guanylate kinase-like region, two WW domains, and multiple PDZ domains (1). AIP2 (WWP2), AIP4 (itchy), and AIP5 (WWP1) are highly homologous, each having four WW domains and a HECT domain characteristic of ubiquitin ligases (1-3). These interactors are similar to isolated huntingtin-interacting proteins, suggesting commonality of function between two families of proteins responsible for similar diseases (1-3). |