nucleolar

Recognizes the ribosomal RNA gene promoter and activates transcription mediated by RNA polymerase I through cooperative interactions with the transcription factor SL1/TIF-IB complex. It binds specifically to the upstream control element. Nucleolar transcription factor 1 Protein, Human, Recombinant (E. coli, His & SUMO) is expressed in E. coli expression system with N-6xHis-SUMO tag. The predicted molecular weight is 95.2 kDa and the accession number is P17480.

Recognizes the ribosomal RNA gene promoter and activates transcription mediated by RNA polymerase I through cooperative interactions with the transcription factor SL1/TIF-IB complex. It binds specifically to the upstream control element. Nucleolar transcription factor 1 Protein, Human, Recombinant (Cell-Free, His & SUMO) is expressed in E. coli expression system with N-10xHis-SUMO tag. The predicted molecular weight is 107.9 kDa and the accession number is P17480.

Nucleolar Protein 3 is encoded by NOL3 gene; multiple transcript variants encoding different isoforms have been found for this gene. So far, Nucleolar protein 3 has show to have two Isoforms. Isoform 1 may be involved in RNA splicing.Isoform 2 may inhibit apoptosis.It has been shown to down-regulate the enzyme activities of caspase 2, caspase 8 and tumor protein p53.

Nucleolar protein 3 is encoded by NOL3 gene. Multiple transcript variants encoding different isoforms have been found for this gene. So far, Nucleolar protein 3 has show to have two Isoforms. Isoform 1 may be involved in RNA splicing. Isoform 2 functions as an apoptosis repressor that blocks multiple modes of cell death. It inhibits extrinsic apoptotic pathways through two different ways. Firstly, it by interacting with FAS and FADD upon FAS activation blocking death-inducing signaling complex (DISC) assembly. Secondly by interacting with CASP8 in a mitochondria localization- and phosphorylation-dependent manner, limiting the amount of soluble CASP8 available for DISC-mediated activation. It has been shown to down-regulate the enzyme activities of caspase 2, caspase 8 and tumor protein p53.

NHP2 belongs to the H/ACA snoRNPs gene family. snoRNPs are involved in various aspects of rRNA processing and modification and have been organized into 2 families: C/D and H/ACA. NHP2 forms a small ribonucleoprotein particle with GAR1 (NOLA1). NHP2 is involved in a variety of aspects of rRNA processing and modification. NHP2 localizes to the dense fibrillar component of the nucleolus and in nuclear Cajal bodies. NHP2 may also be required for correct processing or intranuclear trafficking of TERC, the RNA component of the telomerase reverse transcriptase (TERT) holoenzyme.

Nucleophosmin Protein, Mouse, Recombinant (His & SUMO) is expressed in E. coli expression system with N-6xHis-SUMO tag. The predicted molecular weight is 48.6 kDa and the accession number is Q61937.

Nucleophosmin Protein, Human, Recombinant (His) is expressed in E. coli expression system with His tag. The predicted molecular weight is 17.8 kDa and the accession number is P06748-1.

Nucleophosmin Protein, Human, Recombinant (aa 2-294, His) is expressed in E. coli expression system with His tag. The predicted molecular weight is 34 kDa and the accession number is P06748-1.

MKI67 contains 1 FHA domain and plays a key role in cell proliferation. During interphase, the MKI67 antigen can be exclusively detected within the cell nucleus, whereas in mitosis most of the protein is relocated to the surface of the chromosomes. MKI67 protein is present during all active phases of the cell cycle (G1, S, G2, and mitosis), but is absent from resting cells. MKI67 is an excellent marker to determine the growth fraction of a given cell population. The fraction of MKI67-positive tumor cells is often correlated with the clinical course of cancer. It is also associated with ribosomal RNA transcription. Inactivation of antigen MKI67 leads to inhibition of ribosomal RNA synthesis. The MKI67 protein is a nuclear and nucleolar protein, which is tightly associated with somatic cell proliferation. Antibodies raised against the human MKI67 protein paved the way for the immunohistological assessment of cell proliferation, particularly useful in numerous studies on the prognostic value of cell growth in clinical samples of human neoplasms. MKI67 protein expression is an absolute requirement for progression through the cell-division cycle. Recently, MKI67 is proved to be an independent prognostic factor for disease-free survival (HR 1.5-1.72) in multivariate analyses studies using samples from randomized clinical trials with secondary central analysis of the biomarker. MKI67 was not found to be predictive for long-term follow-up after chemotherapy. Nevertheless, high KI-67 was found to be associated with immediate pathological complete response in the neoadjuvant setting, with an LOE of II-B. MKI67 could be considered as a prognostic biomarker for therapeutic decision.

Nucleolin is the major nucleolar protein of growing eukaryotic cells. It is found associated with intranucleolar chromatin and pre-ribosomal particles. It induces chromatin decondensation by binding to histone H1. It is thought to play a role in pre-rRNA transcription and ribosome assembly. May play a role in the process of transcriptional elongation. Binds RNA oligonucleotides with 5'-UUAGGG-3' repeats more tightly than the telomeric single-stranded DNA 5'-TTAGGG-3' repeats. Nucleolin Protein, Human, Recombinant (His) is expressed in yeast with N-6xHis tag. The predicted molecular weight is 54.4 kDa and the accession number is P19338.

Telomeric repeat binding factor 1 (TRF1), also known as TERF1, the shelterin complex, which modulates the telomere structures. TRF1 protein structure contains a C-terminal Myb motif, a dimerization domain near its N-terminus and an acidic N-terminus. Pin2/TRF1 was originally identified as a protein bound to telomeric DNA (TRF1) and as a protein involved in mitotic regulation (Pin2). Pin2/TRF1 negatively regulates telomere length and importantly, its function is tightly regulated during the cell cycle, acting as an important regulator of mitosis. TRF1 can be bound and modulated by two nucleolar GTP-binding proteins, nucleostemin (NS) and guanine nucleotide binding protein-like 3-like (GNL3L), which exhibit apparently opposite effects on the protein degradation of TRF1. TRF1/TERF1 may has associated with cancer. TRF1 may play a significant role in cell differentiation in non-small cell lung cancer (NSCLC). The expression level of TRF1 protein is significantly reduced in kidney cancer and the level is negatively correlated with malignant degree of the cancer. TRF1 expression in malignant gliomas cells, may play a role in the malignant progression of astroglial brain tumors.

Serine/Threonine-Protein Phosphatase PP1-Υ Catalytic Subunit (PPP1CC) is a member of the PPP phosphatase family. It is essential for cell division, participates in the regulation of glycogen metabolism, muscle contractility and protein synthesis. PPP1CC colocalizes with SPZ1 in the nucleus, with URI1 at mitochondrion, Rapidly exchanges between the nucleolar, nucleoplasmic and cytoplasmic compartments. As a cofactor, PPP1CC binds one iron ion and one manganese ion per subunit.. In addition, PPP1CC may play an important role in dephosphorylating substrates such as the postsynaptic density-associated Ca2+/calmodulin dependent protein kinase II.

Single-stranded DNA-dependent ATP-dependent helicase that plays a key role in DNA non-homologous end joining (NHEJ) by recruiting DNA-PK to DNA. Required for double-strand break repair and V(D)J recombination. Also has a role in chromosome translocation. The DNA helicase II complex binds preferentially to fork-like ends of double-stranded DNA in a cell cycle-dependent manner. It works in the 3'-5' direction. During NHEJ, the XRCC5-XRRC6 dimer performs the recognition step: it recognizes and binds to the broken ends of the DNA and protects them from further resection. Binding to DNA may be mediated by XRCC6. The XRCC5-XRRC6 dimer acts as regulatory subunit of the DNA-dependent protein kinase complex DNA-PK by increasing the affinity of the catalytic subunit PRKDC to DNA by 100-fold. The XRCC5-XRRC6 dimer is probably involved in stabilizing broken DNA ends and bringing them together. The assembly of the DNA-PK complex to DNA ends is required for the NHEJ ligation step. The XRCC5-XRRC6 dimer probably also acts as a 5'-deoxyribose-5-phosphate lyase (5'-dRP lyase), by catalyzing the beta-elimination of the 5' deoxyribose-5-phosphate at an abasic site near double-strand breaks. XRCC5 probably acts as the catalytic subunit of 5'-dRP activity, and allows to 'clean' the termini of abasic sites, a class of nucleotide damage commonly associated with strand breaks, before such broken ends can be joined. The XRCC5-XRRC6 dimer together with APEX1 acts as a negative regulator of transcription. In association with NAA15, the XRCC5-XRRC6 dimer binds to the osteocalcin promoter and activates osteocalcin expression. As part of the DNA-PK complex, involved in the early steps of ribosome assembly by promoting the processing of precursor rRNA into mature 18S rRNA in the small-subunit processome. Binding to U3 small nucleolar RNA, recruits PRKDC and XRCC5/Ku86 to the small-subunit processome. Plays a role in the regulation of DNA virus-mediated innate immune response by assembling into the HDP-RNP complex, a complex that serves as a platform for IRF3 phosphorylation and subsequent innate immune response activation through the cGAS-STING pathway.

Single-stranded DNA-dependent ATP-dependent helicase that plays a key role in DNA non-homologous end joining (NHEJ) by recruiting DNA-PK to DNA. Required for double-strand break repair and V(D)J recombination. Also has a role in chromosome translocation. The DNA helicase II complex binds preferentially to fork-like ends of double-stranded DNA in a cell cycle-dependent manner. It works in the 3'-5' direction. During NHEJ, the XRCC5-XRRC6 dimer performs the recognition step: it recognizes and binds to the broken ends of the DNA and protects them from further resection. Binding to DNA may be mediated by XRCC6. The XRCC5-XRRC6 dimer acts as regulatory subunit of the DNA-dependent protein kinase complex DNA-PK by increasing the affinity of the catalytic subunit PRKDC to DNA by 100-fold. The XRCC5-XRRC6 dimer is probably involved in stabilizing broken DNA ends and bringing them together. The assembly of the DNA-PK complex to DNA ends is required for the NHEJ ligation step. The XRCC5-XRRC6 dimer probably also acts as a 5'-deoxyribose-5-phosphate lyase (5'-dRP lyase), by catalyzing the beta-elimination of the 5' deoxyribose-5-phosphate at an abasic site near double-strand breaks. XRCC5 probably acts as the catalytic subunit of 5'-dRP activity, and allows to 'clean' the termini of abasic sites, a class of nucleotide damage commonly associated with strand breaks, before such broken ends can be joined. The XRCC5-XRRC6 dimer together with APEX1 acts as a negative regulator of transcription. In association with NAA15, the XRCC5-XRRC6 dimer binds to the osteocalcin promoter and activates osteocalcin expression. As part of the DNA-PK complex, involved in the early steps of ribosome assembly by promoting the processing of precursor rRNA into mature 18S rRNA in the small-subunit processome. Binding to U3 small nucleolar RNA, recruits PRKDC and XRCC5/Ku86 to the small-subunit processome. Plays a role in the regulation of DNA virus-mediated innate immune response by assembling into the HDP-RNP complex, a complex that serves as a platform for IRF3 phosphorylation and subsequent innate immune response activation through the cGAS-STING pathway.

SIRT1 belongs to the sirtuin family. Members of the sirtuin family are characterized by a sirtuin core domain and grouped into four classes. SIRT1 is included in class I of the sirtuin family. It is a NAD-dependent protein deacetylase, which regulates processes such as apoptosis and muscle differentiation by deacetylating key proteins. It deacetylates 'Lys-382' of p53/TP53 and impairs its ability to induce proapoptotic program and modulate cell senescence. SIRT1 also deacetylates TAF1B and thereby represses rDNA transcription by the RNA polymerase I. It is involved in HES1- and HEY2-mediated transcriptional repression. SIRT1 inhibits skeletal muscle differentiation by deacetylating PCAF and MYOD1. It may serve as a sensor of the cytosolic ratio of NAD(+)/NADH, which is essential in skeletal muscle cell differentiation. It also deacetylates 'Lys-16' of histone H4 (in vitro). Component of the eNoSC (energy-dependent nucleolar silencing) complex, a complex that mediates silencing of rDNA in response to intracellular energy status and acts by recruiting histone-modifying enzymes. The eNoSC complex is able to sense the energy status of cell: upon glucose starvation, elevation of NAD(+)/NADP(+) ratio activates SIRT1, leading to histone H3 deacetylation followed by dimethylation of H3 at 'Lys-9' (H3K9me2) by SUV39H1 and the formation of silent chromatin in the rDNA locus.