Tip110 maintains expression of pluripotent factors in and pluripotency of human embryonic stem cells.

HIV-1 Tat-interacting protein of 110 kDa [Tip110; p110(nrb)/SART3/p110] is an RNA binding nuclear protein implicated in regulation of HIV-1 gene and host gene transcription, pre-mRNA splicing, and cancer immunology. Recently, we demonstrated a role for Tip110 in regulation of hematopoiesis. Here, we show that TIP110 is also expressed in human embryonic stem cells (hESCs) and expression was decreased with differentiation of these ESCs. TIP110 was found, through up- and down-modulation of expression of Tip110, to be important in maintaining pluripotent factor (NANOG, OCT4, and SOX2) expression in and pluripotency of hESCs, although the mechanisms involved and whether the Tip110 effects are direct remain to be determined. © Mary Ann Liebert, Inc.