This family consists of mammalian kinetochore sub-complex proteins CENP-R, also referred to as nuclear receptor co-activator NRIF3 proteins. NRIF3 exhibits a distinct receptor specificity in interacting with and potentiating the activity of only TRs and RXRs but not other examined nuclear receptors. NRIF3 as a co-regulator that possesses both transactivation and transrepression domains and/or functions. Collectively, the NRIF3 family of co-regulators may play dual roles in mediating both positive and negative regulatory effects on gene expression [1]. CENP-R is one of the 15 components that make up the constitutive centromere associated complex (CCAN) part of the kinetochore. A sub-complex of CCAN, consisting of CENP-P/O/R/Q/U self-assembles on kinetochores with varying stoichiometry and undergoes a pre-mitotic maturation step. Kinetochore assembly is a cell cycle regulated multi-step process. The initial step occurs during interphase and involves loading of the 15-subunit constitutive centromere associated complex (CCAN). Kinetochores are multi-protein megadalton assemblies that are required for attachment of microtubules to centromeres and, in turn, the segregation of chromosomes in mitosis [2,3].

1: Domain structure of the NRIF3 family of coregulators suggests potential dual roles in transcriptional regulation. Li D, Wang F, Samuels HH; Mol Cell Biol 2001;21:8371-8384. PMID:11713274

2: Step-Wise Assembly, Maturation and Dynamic Behavior of the Human CENP-P/O/R/Q/U Kinetochore Sub-Complex. Eskat A, Deng W, Hofmeister A, Rudolphi S, Emmerth S, Hellwig D, Ulbricht T, Doring V, Bancroft JM, McAinsh AD, Cardoso MC, Meraldi P, Hoischen C, Leonhardt H, Diekmann S; PLoS One. 2012;7:e44717. PMID:23028590

3: Kinetochore assembly: if you build it, they will come. Gascoigne KE, Cheeseman IM; Curr Opin Cell Biol. 2011;23:102-108. PMID:20702077