This domain is found in middle of PELP1 (Proline-, glutamic acid- and leucine-rich protein 1, also known as modulator of nongenomic activity of estrogen receptor) which consists of HEAT repeats [1]. PELP1 is a coactivator of estrogen receptor-mediated transcription and a corepressor of other nuclear hormone receptors and sequence-specific transcription factors [2,3]. It forms the Five Friends of Methylated Chtop (5FMC) nuclear complex, together with the Sumo-specific protease Senp3, Wdr18, Tex10, and Las1L, in which it constitutes the core of 5FMC [4]. This complex is recruited by Chromatin target of Prmt1 (Chtop, a vertebrate-specific chromatin-bound protein that plays an important role in transcriptional regulation) when the latter is arginine-methylated by Prmt1 [4].

1: Insights into the evolution of the nucleolus by an analysis of its protein domain repertoire. Staub E, Fiziev P, Rosenthal A, Hinzmann B; Bioessays 2004;26:567-581. PMID:15112237

2: Characterization of the interactions of estrogen receptor and MNAR in the activation of cSrc. Barletta F, Wong CW, McNally C, Komm BS, Katzenellenbogen B, Cheskis BJ; Mol Endocrinol. 2004;18:1096-1108. PMID:14963108

3: Hepatocyte growth factor-regulated tyrosine kinase substrate (HRS) interacts with PELP1 and activates MAPK. Rayala SK, Hollander Pd, Balasenthil S, Molli PR, Bean AJ, Vadlamudi RK, Wang RA, Kumar R; J Biol Chem. 2006;281:4395-4403. PMID:16352611

4: Five friends of methylated chromatin target of protein-arginine-methyltransferase[prmt]-1 (chtop), a complex linking arginine methylation to desumoylation. Fanis P, Gillemans N, Aghajanirefah A, Pourfarzad F, Demmers J, Esteghamat F, Vadlamudi RK, Grosveld F, Philipsen S, van Dijk TB; Mol Cell Proteomics. 2012;11:1263-1273. PMID:22872859