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BioAssay: AID 648269

Inhibition of recombinant GST-tagged human hnRNP A1/his-tagged top1 cap region interaction expressed in Escherichia coli by SPR biosensor analysis

Camptothecin (CPT) is an anti-tumor natural product that forms a ternary complex with topoisomerase I (top I) and DNA (CPT-top I-DNA). In this study, we identified the direct interaction between CPT and human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) using the T7 phage display technology. On an avidin-agarose bead pull down assay, hnRNP A1 protein was selectively pulled down in the more ..
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AID: 648269
Data Source: ChEMBL (805717)
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2012-09-09
Modify Date: 2013-11-17

Data Table ( Complete ):           Active    All
Target
Sequence: RecName: Full=Heterogeneous nuclear ribonucleoprotein A1; Short=hnRNP A1; AltName: Full=Helix-destabilizing protein; AltName: Full=Single-strand RNA-binding protein; AltName: Full=hnRNP core protein A1
Description ..   
Protein Family: RNA recognition motif 1 in heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) and similar proteins
Comment ..   

Gene:HNRNPA1     Related Protein 3D Structures     More BioActivity Data..
BioActive Compound: 1
Description:
Title: Camptothecin (CPT) directly binds to human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) and inhibits the hnRNP A1/topoisomerase I interaction.

Abstract: Camptothecin (CPT) is an anti-tumor natural product that forms a ternary complex with topoisomerase I (top I) and DNA (CPT-top I-DNA). In this study, we identified the direct interaction between CPT and human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) using the T7 phage display technology. On an avidin-agarose bead pull down assay, hnRNP A1 protein was selectively pulled down in the presence of C20-biotinylated CPT derivative (CPT-20-B) both in vitro and in vivo. The interaction was also confirmed by an analysis on a quartz-crystal microbalance (QCM) device, yielding a K(D) value of 82.7 nM. A surface plasmon resonance (SPR) analysis revealed that CPT inhibits the binding of hnRNP A1 to top I (K(D): 260 nM) in a non-competitive manner. Moreover, an in vivo drug evaluation assay using Drosophila melanogaster showed that the knockout of the hnRNP A1 homolog Hrb87F gene showed high susceptibility against 5-50 muM of CPT as compared to a wild-type strain. Such susceptibility was specific for CPT and not observed after treatment with other cytotoxic drugs. Collectively, our data suggests that CPT directly binds to hnRNP A1 and non-competitively inhibits the hnRNP A1/top I interaction in vivo. The knockout strain loses the hnRNP A1 homolog as a both CPT-binding partner and naive brakes of top I, which enhances the formation of the CPT-top I-DNA ternary complexes and subsequently sensitizes the growth inhibitory effect of CPT in D. melanogaster.
(PMID: 22071521)
Categorized Comment
ChEMBL Assay Type: Binding

ChEMBL Assay Data Source: Scientific Literature

ChEMBL Target ID: 104463

ChEMBL Target Type: Target is a single protein chain

Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Inhibition activity commentInhibition activity commentString
2Inhibition standard flagInhibition standard flagInteger
3Inhibition qualifierInhibition qualifierString
4Inhibition published valueInhibition published valueFloat
5Inhibition standard valueInhibition standard valueFloat

Data Table (Concise)
Classification
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