Spinal muscular atrophy (SMA) is caused by insufficient levels of the survival motor neuron protein SMN. The SMN locus on chromosome 5q13 contains two inverted copies of SMN called SMN1 and SMN2 which are 99% identical at the amino acid level. SMN1 is a fully functional protein and SMN2 skips exon 7 90% of the time. Skipping of exon 7 produces non-functional protein product. 10% of the SMN2 more ..
Related BioAssays
Related BioAssays
Target
| Sequence: survival of motor neuron 2, centromeric isoform d [Homo sapiens] Protein Family: TUDOR Gene:SMN2 Related Protein 3D Structures |
Depositor Specified Assays
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| AID | Name | Type | Comment |
|---|---|---|---|
| 1458 | qHTS Assay for Enhancers of SMN2 Splice Variant Expression | confirmatory | Primary qHTS screen for enhancers of SMN protein production from SMN2 gene. |
| 1733 | Counterscreen Assay for Enhancers of SMN2 Splice Variant Expression: Interaction with Luciferase Reporter | confirmatory | Counterscreen for inhibitors of luciferase purified enzyme. |
| 1739 | Counterscreen Assay for Enhancers of SMN2 Splice Variant Expression: Modulation of SMN1 Expression | confirmatory | Assay for modulators of SMN protein production from SMN1 gene. |
| 1740 | Confirmation Concentration-Response Assay for Enhancers of SMN2 Splice Variant Expression | confirmatory | Confirmation screen for enhancers of SMN protein production from SMN2 gene. |
| 2513 | Counterscreen Assay for Enhancers of SMN2 Splice Variant Expression: Modulation of SMN1 Expression for Probe SAR | confirmatory | Assay for modulators of SMN protein production from SMN1 gene. |
| 2514 | Confirmation Concentration-Response Assay for Enhancers of SMN2 Splice Variant Expression for Probe SAR | confirmatory | Confirmation screen for enhancers of SMN protein production from SMN2 gene. |
| 2515 | Counterscreen Assay for Enhancers of SMN2 Splice Variant Expression: Interaction with Luciferase Reporter for Probe SAR | confirmatory | Counterscreen for inhibitors of luciferase purified enzyme. |
| 488832 | Confirmation Concentration-Response Assay for Enhancers of SMN2 Splice Variant Expression for Further Probe SAR | confirmatory | Confirmation screen for enhancers of SMN protein production from SMN2 gene. |
| 488821 | Counterscreen Assay for Enhancers of SMN2 Splice Variant Expression: Modulation of SMN1 Expression for Further Probe SAR | confirmatory | Assay for modulators of SMN protein production from SMN1 gene. |
| 488838 | Counterscreen Assay for Enhancers of SMN2 Splice Variant Expression: Interaction with Luciferase Reporter for Further Probe SAR | confirmatory | Counterscreen for inhibitors of luciferase purified enzyme. |
| 504776 | Enhancers of SMN2 Splice Variant Expression: Metabolic Stability in presence of NADPH Profiling | other | |
| 504779 | Enhancers of SMN2 Splice Variant Expression: Efflux Ratio Profiling | other | |
| 504778 | Enhancers of SMN2 Splice Variant Expression: Caco-2 Permeability Profiling | other | |
| 504777 | Enhancers of SMN2 Splice Variant Expression: Metabolic Stability in absence of NADPH Profiling | other | |
| 687010 | On Hold | ||
| 687011 | On Hold | ||
| 687012 | On Hold |
Description:
NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Production centers Network [MLPCN]
MLPCN Grant: R03 MH084179-01
Assay Submitter (PI): Elliot Androphy
NCGC Assay Overview:
Spinal muscular atrophy (SMA) is caused by insufficient levels of the survival motor neuron protein SMN. The SMN locus on chromosome 5q13 contains two inverted copies of SMN called SMN1 and SMN2 which are 99% identical at the amino acid level. SMN1 is a fully functional protein and SMN2 skips exon 7 90% of the time. Skipping of exon 7 produces non-functional protein product. 10% of the SMN2 protein includes exon 7 and is fully functional. In the SMA disease state, mutations in the SMN1 locus are the cause of the disease state. Because only 10% of SMN2 is of the fully functional form, it is not sufficient to overcome the deficiency produced by the loss of the SMN1 product. A therapy that either increase the amount of SMN2 product made or to increase the inclusion of exon 7 has been proposed for the treatment of SMA.
We have designed an assay to identify small molecules that can increase the amount of functional SMN2 product by appending a luciferase reporter gene after the native SMN2 gene, such that inclusion of exon 7 in the expressed product places the luciferase sequence in frame, thus generating functional luciferase enzyme.
NIH Molecular Libraries Probe Production centers Network [MLPCN]
MLPCN Grant: R03 MH084179-01
Assay Submitter (PI): Elliot Androphy
NCGC Assay Overview:
Spinal muscular atrophy (SMA) is caused by insufficient levels of the survival motor neuron protein SMN. The SMN locus on chromosome 5q13 contains two inverted copies of SMN called SMN1 and SMN2 which are 99% identical at the amino acid level. SMN1 is a fully functional protein and SMN2 skips exon 7 90% of the time. Skipping of exon 7 produces non-functional protein product. 10% of the SMN2 protein includes exon 7 and is fully functional. In the SMA disease state, mutations in the SMN1 locus are the cause of the disease state. Because only 10% of SMN2 is of the fully functional form, it is not sufficient to overcome the deficiency produced by the loss of the SMN1 product. A therapy that either increase the amount of SMN2 product made or to increase the inclusion of exon 7 has been proposed for the treatment of SMA.
We have designed an assay to identify small molecules that can increase the amount of functional SMN2 product by appending a luciferase reporter gene after the native SMN2 gene, such that inclusion of exon 7 in the expressed product places the luciferase sequence in frame, thus generating functional luciferase enzyme.
Protocol
Please refer to other AIDs (1458, 1733, 1739, 1740, 2513, 2514, 2515) for detailed assay protocols. Western blot protocol details are given in PMID: 15555999.
Comment
This summary is written for the purposes of summarizing the probe activities from the project. MLSCN probes are given a score of 100. Molecules in the prior art are given a score of 80. Other, less active molecules in the same chemical series as the probe molecules are given a score of 50. Molecules pending validation are given a score of 10. Inactive analogues from these series are given a score of 0. The present results represent the lead series after confirmation of enhanced SMN protein production in a patient derived fibroblast model. ML104 (CID 6404603) and ML153 (CID 990823) were declared as probes from this project.
Result Definitions
| TID | Name | Description | Histogram | Type | Unit | |
|---|---|---|---|---|---|---|
| Outcome | The BioAssay activity outcome | Outcome | ||||
| Score | The BioAssay activity ranking score |  | Integer | |||
| 1 | Activity Summary | Nature of interaction of the sample with the receptor. | String | |||
| 2 | SMN Protein Expression in Patient Derived Fibroblasts | A description of results from a Western Blot for SMN protein in patient derived fibroblasts after incubation with compounds according to details in PMID 15555999. | String | |||
| 3 | SMN2 Reporter Assay AC50 | The concentration of sample yielding half-maximal enhancement of alternate splice form expression in a luciferase-based reporter assay. | | Float | μM | |
| 4 | Luciferase IC50 | The concentration of sample yielding half-maximal inhibition of purified luciferase in an in vitro assay. | | Float | μM | |
| 5 | SMN1 Reporter Assay IC50 | The concentration of sample yielding half-maximal modulation of alternate splice form expression in a luciferase-based reporter assay. | | Float | μM |
Additional Information
Grant Number: R03 MH084179-01
Data Table (Concise)
Classification
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