DNA- and RNA-binding protein involved in several cellular processes such as nuclear chromatin organization, telomere-length regulation, transcription, mRNA alternative splicing and stability, Xist-mediated transcriptional silencing and mitotic cell progression (  , ). Plays a role in the regulation of interphase large-scale gene-rich chromatin organization through chromatin-associated RNAs (caRNAs) in a transcription-dependent manner, and thereby maintains genomic stability ( ). Required for the localization of the long non-coding Xist RNA on the inactive chromosome X (Xi) and the subsequent initiation and maintenance of X-linked transcriptional gene silencing during X-inactivation (By similarity). Plays a role as a RNA polymerase II (Pol II) holoenzyme transcription regulator (  , ). Promotes transcription initiation by direct association with the core-TFIIH basal transcription factor complex for the assembly of a functional pre-initiation complex with Pol II in a actin-dependent manner (, ). Blocks Pol II transcription elongation activity by inhibiting the C-terminal domain (CTD) phosphorylation of Pol II and dissociates from Pol II pre-initiation complex prior to productive transcription elongation . Positively regulates CBX5-induced transcriptional gene silencing and retention of CBX5 in the nucleus . Negatively regulates glucocorticoid-mediated transcriptional activation . Key regulator of transcription initiation and elongation in embryonic stem cells upon leukemia inhibitory factor (LIF) signaling (By similarity). Involved in the long non-coding RNA H19-mediated Pol II transcriptional repression . Participates in the circadian regulation of the core clock component BMAL1 transcription (By similarity). Plays a role in the regulation of telomere length . Plays a role as a global pre-mRNA alternative splicing modulator by regulating U2 small nuclear ribonucleoprotein (snRNP) biogenesis . Plays a role in mRNA stability ( ). Component of the CRD-mediated complex that promotes MYC mRNA stabilization . Enhances the expression of specific genes, such as tumor necrosis factor TNFA, by regulating mRNA stability, possibly through binding to the 3'-untranslated region (UTR) . Plays a role in mitotic cell cycle regulation (, ). Involved in the formation of stable mitotic spindle microtubules (MTs) attachment to kinetochore, spindle organization and chromosome congression . Phosphorylation at Ser-59 by PLK1 is required for chromosome alignement and segregation and progression through mitosis . Contributes also to the targeting of AURKA to mitotic spindle MTs . Binds to double- and single-stranded DNA and RNA, poly(A), poly(C) and poly(G) oligoribonucleotides (  ). Binds to chromatin-associated RNAs (caRNAs) . Associates with chromatin to scaffold/matrix attachment region (S/MAR) elements in a chromatin-associated RNAs (caRNAs)-dependent manner (   , ). Binds to the Xist RNA . Binds the long non-coding H19 RNA . Binds to SMN1/2 pre-mRNAs at G/U-rich regions . Binds to small nuclear RNAs (snRNAs) . Binds to the 3'-UTR of TNFA mRNA . Binds (via RNA-binding RGG-box region) to the long non-coding Xist RNA; this binding is direct and bridges the Xist RNA and the inactive chromosome X (Xi) (By similarity). Also negatively regulates embryonic stem cell differentiation upon LIF signaling (By similarity). Required for embryonic development (By similarity). Binds to brown fat long non-coding RNA 1 (Blnc1); facilitates the recruitment of Blnc1 by ZBTB7B required to drive brown and beige fat development and thermogenesis (By similarity).
(Microbial infection) Negatively regulates immunodeficiency virus type 1 (HIV-1) replication by preventing the accumulation of viral mRNA transcripts in the cytoplasm.
Subcellular locations: Nucleus, Nucleus matrix, Chromosome, Nucleus speckle, Cytoplasm, Cytoskeleton, Microtubule organizing center, Centrosome, Chromosome, Centromere, Kinetochore, Cytoplasm, Cytoskeleton, Spindle, Cytoplasm, Cytoskeleton, Spindle pole, Midbody, Cytoplasm, Cell surface, Cytoplasmic granule
Localizes at inactive X chromosome (Xi) regions ( ). Localizes in the nucleus during interphase . At metaphase, localizes with mitotic spindle microtubules (MTs) . At anaphase, localizes in the mitotic spindle midzone . Localizes in spindle MTs proximal to spindle poles in a TPX2- and AURKA-dependent manner . The Ser-59 phosphorylated form localizes to centrosomes during prophase and metaphase, to mitotic spindles in anaphase and to the midbody during cytokinesis . Colocalizes with SMARCA4 in the nucleus (By similarity). Colocalizes with CBX5 in the nucleus . Colocalizes with NR3C1 in nuclear speckles . Localized in cytoplasmic ribonucleoprotein (RNP) granules containing untranslated mRNAs .
Widely expressed.