title: TRF2-mediated stabilization of hREST4 is critical for the differentiation and maintenance of neural progenitors.
abstract: Telomere repeat binding factor 2 (TRF2) is a component of the shelterin complex that is known to bind and protect telomeric DNA, yet the detection of TRF2 in extra-telomeric regions of chromosomes suggests other roles for TRF2 besides telomere protection. Here, we demonstrate that TRF2 plays a critical role in antagonizing the repressive function of neuron-restrictive silencer factor, also known as repressor element-1 silencing transcription factor (REST), during the neural differentiation of human embryonic stem cells (hESCs) by enhancing the expression of a truncated REST splice isoform we term human REST4 (hREST4) due to its similarity to rodent REST4. We show that TRF2 is specifically upregulated during hESC neural differentiation concordantly with an increase in the expression of hREST4 and that both proteins are highly expressed in NPCs. Overexpression of TRF2 in hESCs increases hREST4 levels and induces their neural differentiation, whereas TRF2 knockdown in hESCs and NPCs reduces hREST4 expression, hindering their ability to differentiate to the neural lineage. Concurrently, we show that TRF2 directly interacts with the C-terminal of hREST4 through its TRF2 core binding motif [F/Y]xL, protecting hREST4 from ubiquitin-mediated proteasomal degradation and consequently furthering neural induction. Thus, the TRF2-mediated counterbalance between hREST4 and REST is vital for both the generation and maintenance of NPCs, suggesting an important role for TRF2 in both neurogenesis and function of the central nervous system.
authors.affiliation: Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Campus, London, United Kingdom.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ovando-Roche
authors.forename: Jason S L
authors.initials: JS
authors.lastname: Yu
authors.forename: Sarah
authors.initials: S
authors.lastname: Testori
authors.forename: Chloe
authors.initials: C
authors.lastname: Ho
authors.forename: Wei
authors.initials: W
authors.lastname: Cui
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology*; D012097:Repressor Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D035341:Telomeric Repeat Binding Protein 2 / Q000378:metabolism*; D014161:Transduction, Genetic; D015854:Up-Regulation; D000099229:RE1-Silencing Transcription Factor
chemical_list: D012097:Repressor Proteins; D035341:Telomeric Repeat Binding Protein 2; D000099229:RE1-Silencing Transcription Factor; C504753:TERF2 protein, human
keywords: Human embryonic stem cells; Neural differentiation; Neural progenitor cells; REST/REST4; Telomere repeat binding factor 2