3.0
Summary
| Name |  TOP1View Modifications |
| Full Name | DNA topoisomerase 1 |
| Synonyms | DNA topoisomerase I |
| Primary ID | P11387 |
| Links |  -  -  |
| Type | protein |
| Relations | 9 |
| Inhibitors | irinotecan; topotecan |
| Function | Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then rotates around the intact phosphodiester bond on the opposing strand, thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity). Regulates the alternative splicing of tissue factor (F3) pre-mRNA in endothelial cells. Involved in the circadian transcription of the core circadian clock component ARNTL/BMAL1 by altering the chromatin structure around the ROR response elements (ROREs) on the ARNTL/BMAL1 promoter. |
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Modifications Tables
Relations
| Regulator | Mechanism | target | score ℹ | |
|---|---|---|---|---|
| + | CSNK2A1 | up-regulates activity 
phosphorylation
|
TOP1 | 0.392 |
| Publications: | 1 | Organism: | In Vitro | |
| + | CDK1 | up-regulates activity
phosphorylation
|
TOP1 | 0.362 |
| Publications: | 2 | Organism: | In Vitro | |
| + | PRKCA | up-regulates activity
phosphorylation
|
TOP1 | 0.2 |
| Publications: | 1 | Organism: | In Vitro | |
| + | ABL1 | up-regulates activity
phosphorylation
|
TOP1 | 0.41 |
| Publications: | 1 | Organism: | Homo Sapiens | |
| + | SFPQ | up-regulates
binding
|
TOP1 | 0.38 |
| Publications: | 1 | Organism: | Homo Sapiens | |
| + | NONO | up-regulates
binding
|
TOP1 | 0.384 |
| Publications: | 1 | Organism: | Homo Sapiens | |
| + | irinotecan | down-regulates activity 
chemical inhibition
|
TOP1 | 0.8 |
| Publications: | 1 | Organism: | Homo Sapiens | |
| + | topotecan | down-regulates activity
chemical inhibition
|
TOP1 | 0.8 |
| Publications: | 1 | Organism: | Homo Sapiens | |