Anti-TOP3B Antibody Picoband® Fluoro488 Conjugated

DNA topoisomerase 3-beta-1 is an enzyme that in humans is encoded by the TOP3B 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 relaxing the supercoils and altering the topology of DNA. The enzyme interacts with DNA helicase SGS1 and plays a role in DNA recombination, cellular aging and maintenance of genome stability. Low expression of this gene may be related to higher survival rates in breast cancer patients. This gene has a pseudogene on chromosome 22. Alternate splicing results in multiple transcript variants. Additional alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known.

Expressed in immature but not mature T-cells. Also found in CD34+ cells from peripheral blood, CD34+ precursors from umbilical cord blood and adult bone marrow.

Probable E3 ubiquitin-protein ligase that acts as a negative regulator of double-strand breaks (DSBs) repair following DNA damage. Recruited to DSB repair sites by recognizing and binding ubiquitin catalyzed by RNF168 and competes with TP53BP1 and BRCA1 for association with RNF168-modified chromatin, thereby acting as a negative regulator of DSBs repair. E3 ubiquitin-protein ligase activity is not required for regulation of DSBs repair.

1. Kaufman, C. S., Genovese, A., Butler, M. G. Deletion of TOP3B is associated with cognitive impairment and facial dysmorphism. Cytogenet. Genome Res. 150: 106-111, 2016. 2. Kawasaki, K., Minoshima, S., Nakato, E., Shibuya, K., Shintani, A., Schmeits, J. L., Wang, J., Shimizu, N. One-megabase sequence analysis of the human immunoglobulin gamma gene locus. Genome Res. 7: 250-261, 1997. 3. Kwan, K. Y., Moens, P. B., Wang, J. C. Infertility and aneuploidy in mice lacking a type IA DNA topoisomerase III-beta. Proc. Nat. Acad. Sci. 100: 2526-2531, 2003.