Phospho-hnRNP U (Ser271) Antibody - #AF3626

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 ARNTL/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.

Cleaved at Asp-100 by CASP3 during T-cell apoptosis, resulting in a loss of DNA- and chromatin-binding activities.

Extensively phosphorylated. Phosphorylated on Ser-59 by PLK1 and dephosphorylated by protein phosphatase 2A (PP2A) in mitosis.

Arg-739 is dimethylated, probably to asymmetric dimethylarginine (Ref.8). Arg-733 is dimethylated, probably to asymmetric dimethylarginine (By similarity).

Citrullinated by PADI4.

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.
Note: Localizes at inactive X chromosome (Xi) regions (PubMed:11003645, PubMed:14608463, PubMed:15563465). Localizes in the nucleus during interphase (PubMed:21242313). At metaphase, localizes with mitotic spindle microtubules (MTs) (PubMed:21242313). At anaphase, localizes in the mitotic spindle midzone (PubMed:21242313). Localizes in spindle MTs proximal to spindle poles in a TPX2- and AURKA-dependent manner (PubMed:21242313). The Ser-59 phosphorylated form localizes to centrosomes during prophase and metaphase, to mitotic spindles in anaphase and to the midbody during cytokinesis (PubMed:25986610). Colocalizes with SMARCA4 in the nucleus (By similarity). Colocalizes with CBX5 in the nucleus (PubMed:19617346). Colocalizes with NR3C1 in nuclear speckles (PubMed:9353307). Localized in cytoplasmic ribonucleoprotein (RNP) granules containing untranslated mRNAs (PubMed:17289661).

Widely expressed.

Oligomer (via ATPase domain and RNA-binding RGG-box region); oligomerization occurs upon ATP-binding in a chromatin-associated RNAs (caRNAs)- and transcription-dependent manner and is required for chromatin decompaction. ATP hydrolysis is required to cycle from an oligomeric to monomeric state to compact chromatin. Component of the coding region determinant (CRD)-mediated complex, composed of DHX9, HNRNPU, IGF2BP1, SYNCRIP and YBX1. Identified in the spliceosome C complex. Identified in a IGF2BP1-dependent mRNP granule complex containing untranslated mRNAs. Associates with heterogeneous nuclear ribonucleoprotein (hnRNP) particles. Associates (via middle region) with the C-terminal domain (CTD) RNA polymerase II (Pol II) holoenzyme; this association occurs in a RNA-independent manner. Associates (via middle region) with the core-TFIIH basal transcription factor complex; this association inhibits the CTD phosphorylation of RNA polymerase II holoenzyme by downregulating TFIIH kinase activity. Associates with the telomerase holoenzyme complex. Associates with spindle microtubules (MTs) in a TPX2-dependent manner. Interacts (via C-terminus) with actin; this interaction is direct and mediates association with the phosphorylated CTD of RNA polymerase II and is disrupted in presence of the long non-coding H19 RNA. Interacts with AURKA. Interacts (via C-terminus) with CBX5; this interaction is, at least in part, RNA-dependent. Interacts with CR2. Interacts with CRY1 (By similarity). Interacts (via C-terminus) with EP300; this interaction enhances DNA-binding to nuclear scaffold/matrix attachment region (S/MAR) elements. Interacts with ERBB4. Interacts with GEMIN5. Interacts with IGF2BP1. Interacts with IGF2BP2 and IGF2BP3. Interacts with NCL; this interaction occurs during mitosis. Interacts (via C-terminus) with NR3C1 (via C-terminus). Interacts with PLK1; this interaction induces phosphorylation of HNRNPU at Ser-59 in mitosis. Interacts with POU3F4. Interacts with SMARCA4; this interaction occurs in embryonic stem cells and stimulates global Pol II-mediated transcription. Interacts (via C-terminus) with TOP2A; this interaction protects the topoisomerase TOP2A from degradation and positively regulates the relaxation of supercoiled DNA by TOP2A in a RNA-dependent manner (By similarity). Interacts with TPX2; this interaction recruits HNRNPU to spindle microtubules (MTs). Interacts with UBQLN2. Interacts (via RNA-binding RGG-box region) with ZBTB7B; the interaction facilitates the recruitment of long non-coding RNA Blnc1 by ZBTB7B (By similarity). Interacts with ERCC6.

(Microbial infection) Interacts with HIV-1 protein Rev.

The SAP domain is necessary for specific binding to nuclear scaffold/matrix attachment region (S/MAR) elements in DNA (PubMed:9405365, PubMed:11003645). The RNA-binding RGG-box region is necessary for its association with inactive X chromosome (Xi) regions and to chromatin-associated RNAs (caRNAs) (PubMed:14608463, PubMed:28622508). Both the DNA-binding domain SAP and the RNA-binding RGG-box region are necessary for the localization of Xist RNA on the Xi (By similarity). The ATPase and RNA-binding RGG-box regions are necessary for oligomerization (PubMed:28622508).