The alphabet of intrinsic disorder: II. Various roles of glutamic acid in ordered and intrinsically disordered proteins

Uversky, Vladimir N

PELP1. Proline-, glutamic acid-and leucine-rich protein-1 (PELP1) plays an important role in mediation of genomic and nongenomic signaling of β-estradiol. 191 This potential protooncogene functions as a co-regulator of estrogen receptor, and expression of PELP1 is deregulated during breast cancer progression. 192 PELP1 contains ten nuclear receptor-interacting boxes (LXXLL motifs), which allow it to interact with estrogen receptor and other nuclear hormone receptors, a zinc finger, a glutamic acid-rich domain and two proline-rich domains. 191 There are several consensus PXXP motifs within the proline-rich regions, via which PELP1 couples the estrogen receptor (ER) with SH3 domain-containing kinase signaling proteins, such as Src and PI3K P85 regulatory subunit. 191 There are 148 glutamic acids in PELP1 (which is 1,130 residues long), and the majority of them (99) are concentrated within the glutamic acid-rich domain (residues 888-1101).