The PELP1 protein encodes a protein of 1130 amino acids, and exhibits both cytoplasmic and nuclear localization depending on the tissue. PELP1 lacks known enzymatic activity and functions as a scaffolding protein. It contains 10 NR-interacting boxes (LXXLL motifs) and functions as a coregulator of several nuclear receptors via its LXXLL motifs including ESR1,  ESR2, ERR-alpha, PR, GR, AR, and RXR. PELP1 also functions as a coregulator of several other transcription factors, including AP1, SP1, NFkB, STAT3, and FHL2.
PELP1 has a histone binding domain and interacts with chromatin-modifying complexes, including CBP/p300, histone deacetylase 2, histones,  SUMO2, lysine-specific demethylase 1 (KDM1), PRMT6, and CARM1.   PELP1 also  interacts with cell cycle regulators such as pRb. E2F1, and p53.
PELP1 is phosphorylated by hormonal and growth factor signals. PELP1 phosphorylation status is also influenced by cell cycle progression, and it is a substrate of CDKs.  Further, PELP1 is phosphorylated by DNA damage induced kinases (ATM, ATR, DNA-PKcs).