Specific binding of heterogeneous ribonucleoprotein particle protein K to the human c-myc promoter, in vitro.

Takimoto, Masato; Tomonaga, Takeshi; Matunis, Michael J.; Avigan, Mark; Krutzsch, Henry C.; Dreyfuss, Gideon; Levens, David

doi:10.1016/s0021-9258(17)46837-2

Cited by 211 publications

(44 citation statements)

References 46 publications

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“…The PCR product was cleaved with EcoRI and was cloned into pcDNAIlAmp. The reporter plasmids t>56-mut was described in Takimoto et al (3). t>56CT3 was constructed by inserting the double-stranded CT3 oligonucleotides into HindIII site of t>56.…”

Section: Methodsmentioning

confidence: 99%

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Heterogeneous Nuclear Ribonucleoprotein K Is a DNA-binding Transactivator

Tomonaga

Levens

1995

Journal of Biological Chemistry

173

171

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We have previously reported that heterogeneous nuclear ribonucleoprotein K (hnRNP K) binds to the pyrimidine-rich strand of the CT element found in the human c-myc gene and activates CT reporter-driven gene expression in vivo. We now characterize the DNA and protein requirements for the interaction of hnRNP K with the CT element. First, hnRNP K is shown to preferentially bind single-stranded DNA over RNA or native double-stranded DNA. Using specific oligoribonucleotide or deoxyribonucleotide probes with specific or nonspecific RNA or DNA competitors, electrophoretic mobility shift assay revealed hnRNP K to be a DNA-binding protein. Specific binding was not simply a reflection of binding to pyrimidine-rich sequences as the number and arrangement of individual CT elements governed interactions with hnRNP K; at least two CT repeats separated by at least three nucleotides are required for binding, indicating the existence of particular stereochemical constraints regulating CT-hnRNP K complex formation. Deletion analysis showed that hnRNP K possesses several nonoverlapping, DNA binding domains, each capable of specific binding with the CT element and preferring DNA over RNA. Each sequence recognition domain is composed of at least one K homology motif, while a larger portion of hnRNP K may be required for stable RNA binding. Additional experiments indicate that the N-terminal 35 residues of hnRNP K are necessary for transactivating the CT element. These results indicate that hnRNP K is a DNA-binding protein and transcriptional activator.

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Section: Methodsmentioning

confidence: 99%

“…However, several recent reports suggest that this same protein is a DNAbinding protein. We have previously shown that hnRNP K binds and transactivates a cis-element found within the human c-myc promoter (3). hnRNP K, when phosphorylated, has also been reported to bind the human immunodeficiency virus-long terminal repeat KB site (4).…”

mentioning

confidence: 99%

Heterogeneous Nuclear Ribonucleoprotein K Is a DNA-binding Transactivator

Tomonaga

Levens

1995

Journal of Biological Chemistry

173

171

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“…The hnRNP K knockdown in NB4 and NB4-R2 cells reduced c-Myc protein and proliferation. In this regard, it has been reported that hnRNP K regulates the activation of transcription and translation of c-Myc [38,39], which is directly involved in cell proliferation and cell cycle progression [40], and it is a potential therapeutic target in AML via apoptosis induction [41]. The cell death induced by hnRNP K knockdown in NB4 and NB4-R2 cells is promoted at least in part by the reduction in Bcl-xL protein (anti-apoptotic) and procaspase-3, suggesting apoptosis induction [42].…”

Section: Discussionmentioning

confidence: 99%

Crosstalk between hnRNP K and SET in ATRA‐induced differentiation in acute promyelocytic leukemia

et al. 2021

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HnRNP K protein is a heterogeneous nuclear ribonucleoprotein which has been proposed to be involved in the leukemogenesis of acute promyelocytic leukemia (APL), as well as in differentiation induced by all‐trans retinoic acid (ATRA). We previously demonstrated a connection between SET and hnRNP K function in head and neck squamous cell carcinoma (HNSCC) cells related to splicing processing. The objective of this study was to characterize the participation of hnRNP K and SET proteins in ATRA‐induced differentiation in APL. We observed higher (5‐ to 40‐fold) levels of hnRNP K and SET mRNA in APL patients at the diagnosis phase compared with induction and maintenance phases. hnRNP K knockdown using short‐hairpin RNA led to cell death in ATRA‐sensitive NB4 and resistant NB4‐R2 cells by apoptosis with SET cleavage. In addition, hnRNP K knockdown increased granulocytic differentiation in APL cells, mainly in NB4‐R2 with ATRA. hnRNP K knockdown had an effect similar to that of treatment with U0126 (an meiosis‐specific serine/threonine protein kinase/ERK inhibitor), mainly in NB4‐R2 cells. SET knockdown in APL cells revealed that apoptosis induction in cells with hnRNP K knockdown occurred by SET cleavage rather than by reduction in SET protein. Transplantation of NB4‐R2 cells into nude mice confirmed that arsenic trioxide (ATO) combined with U0126 has higher potential against tumor progression when compared to ATO. Therefore, hnRNP K/SET and ERK are potential therapeutic targets for both antineoplastic leukemia therapy and relapsed APL patients with ATRA resistance.

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“…Other nuclear proteins have also been shown to bind such CT elements. For example, an element containing 5 imperfect repeats of 5Ј-CCCTCCCCA-3Ј in the promoter of the human c-myc proto-ocogene was shown to bind Sp1/Sp3, the myc-associated zinc finger protein (45) and two single-stranded DNA binding proteins hnRNP K (46) and CNBP (47). As we used only double-stranded oligonucleotide probes for EMSA, we cannot exclude the possibility that single-stranded DNA binding proteins, such as hnRNP K and CNBP, may bind to the CT element and modulate the LPL promoter activity.…”

Section: Discussionmentioning

confidence: 99%

Sp1 and Sp3 transactivate the human lipoprotein lipase gene promoter through binding to a CT element: synergy with the sterol regulatory element binding protein and reduced transactivation of a naturally occurring promoter variant

Yang

Deeb

1998

Journal of Lipid Research

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Lipoprotein lipase (LPL) is a key enzyme in lipoprotein and energy metabolism and, therefore, regulation of its expression could have an important bearing on these processes. We have identified an evolutionarily conserved 5 -CCTCCCCCC-3 motif (from ؊ 91 to ؊ 83, CT element) in the human LPL gene promoter, deletion or mutation of which caused approximately 70-80% decrease in promoter activity. We found that Sp1 and Sp3 in THP-1 nuclear protein extracts bind specifically to this element. Co-transfection with Sp1 and Sp3 expression plasmids transactivated the LPL promoter via the CT element in Drosophila SL2 cells devoid of Sp proteins. Sp3 moderately repressed Sp1mediated LPL promoter activation when both were coexpressed in SL2 cells. Furthermore, co-expression of an active sterol regulatory element binding protein (SREBP-1), with Sp1, but not with Sp3, synergistically activated the LPL promoter in SL2 cells. We previously reported a naturally occurring T ¨ G substitution at position ؊ 93 of the human LPL promoter which reduces promoter activity by 40-50% in transient transfection assays. In this study, we showed that this substitution results in reduced binding affinity to Sp1/Sp3 and in diminished transactivation by Sp1/Sp3 alone and by the synergistic action of Sp1 and SREBP-1. In conclusion, recruitment of Sp1/Sp3 by the CT element may play an important role in expression of the human lipoprotein lipase gene. Synergistic transcriptional activation by Sp1 and SREBP-1 may provide a mechanism for cross-talk between cholesterol and triglyceride metabolic pathways.-Yang, W-S., and S. S. Deeb. Sp1 and Sp3 transactivate the human lipoprotein lipase gene promoter through binding to a CT element: synergy with the sterol regulatory element binding protein and reduced transactivation of a naturally occurring promoter variant.

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Specific binding of heterogeneous ribonucleoprotein particle protein K to the human c-myc promoter, in vitro.

Cited by 211 publications

References 46 publications

Heterogeneous Nuclear Ribonucleoprotein K Is a DNA-binding Transactivator

Heterogeneous Nuclear Ribonucleoprotein K Is a DNA-binding Transactivator

Crosstalk between hnRNP K and SET in ATRA‐induced differentiation in acute promyelocytic leukemia

Sp1 and Sp3 transactivate the human lipoprotein lipase gene promoter through binding to a CT element: synergy with the sterol regulatory element binding protein and reduced transactivation of a naturally occurring promoter variant

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