Anti-Topoisomerase I/TOP1 Antibody Picoband® Fluoro488 Conjugated

DNA topoisomerase 1 is an enzyme that in humans is encoded by the TOP1 gene. This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus altering the topology of DNA. This gene is localized to chromosome 20 and has pseudogenes which reside on chromosomes 1 and 22.

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.

1. Entrez Gene: TOP1 topoisomerase (DNA) I. 2. Ahuja, H. G., Felix, C. A., Aplan, P. D. The t (11;20) (p15; q11) chromosomal translocation associated with therapy-related myelodysplastic syndrome results in an NUP98-TOP1fusion. Blood 94: 3258-3261, 1999.