title: Nuclear receptor coactivator/coregulator NCoA6(NRC) is a pleiotropic coregulator involved in transcription, cell survival, growth and development.
abstract: NCoA6 (also referred to as NRC, ASC-2, TRBP, PRIP and RAP250) was originally isolated as a ligand-dependent nuclear receptor interacting protein. However, NCoA6 is a multifunctional coregulator or coactivator necessary for transcriptional activation of a wide spectrum of target genes. The NCoA6 gene is amplified and overexpressed in breast, colon and lung cancers. NCoA6 is a 250 kDa protein which harbors a potent N-terminal activation domain, AD1; and a second, centrally-located activation domain, AD2, which is necessary for nuclear receptor signaling. The intrinsic activation potential of NCoA6 is regulated by its C-terminal STL regulatory domain. Near AD2 is an LxxLL-1 motif which interacts with a wide spectrum of ligand-bound NRs with high-affinity. A second LxxLL motif (LxxLL-2) located towards the C-terminal region is more restricted in its NR specificity. The potential role of NCoA6 as a co-integrator is suggested by its ability to enhance transcriptional activation of a wide variety of transcription factors and from its in vivo association with a number of known cofactors including CBP/p300. NCoA6 has been shown to associate with at least three distinct coactivator complexes containing Set methyltransferases as core polypeptides. The composition of these complexes suggests that NCoA6 may play a fundamental role in transcriptional activation by modulating chromatin structure through histone methylation. Knockout studies in mice suggest that NCoA6 is an essential coactivator. NCoA6-/- embryos die between 8.5-12.5 dpc from general growth retardation coupled with developmental defects in the heart, liver, brain and placenta. NCoA6-/- MEFs grow at a reduced rate compared to WT MEFs and spontaneously undergo apoptosis, indicating the importance of NCoA6 as a prosurvival and anti-apoptotic gene. Studies with NCoA6+/- and conditional knockout mice suggest that NCoA6 is a pleiotropic coregulator involved in growth, development, wound healing and maintenance of energy homeostasis.
authors.affiliation: Department of Pharmacology, NYU School of Medicine, New York, New York, USA. muktar.mahajan@med.nyu.edu
authors.forename: Muktar A
authors.initials: MA
authors.lastname: Mahajan
authors.forename: Herbert H
authors.initials: HH
authors.lastname: Samuels
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000235:genetics / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005809:Genes, Regulator / Q000235:genetics / Q000502:physiology*; D048788:Growth and Development / Q000235:genetics / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008780:Methyltransferases / Q000378:metabolism; D056918:Nuclear Receptor Coactivators; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology; D050880:p300-CBP Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C486559:NCOA6 protein, human; D056918:Nuclear Receptor Coactivators; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D008780:Methyltransferases; D050880:p300-CBP Transcription Factors