Replication licensing

Chong JP, Thommes P, Rowles A, Mahbubani HM, Blow JJ 1997 Characterization of the Xenopus replication licensing system. Methods Enzymol 283 549-564 Dasso M, Newport JW 1990 Completion of DNA replication is monitored by a feedback system that controls the initiation of mitosis in vitro-, studies in Xenopus. Cell 61 811-823... 

Nishitani, H. lygerou, Z. (2002) Control of DNA replication licensing in a cell cycle. Genes Cells 7, 523-534. 

The regulatory factors that control initiation of replication of chromosomal DNA are the replication licensing factors (RTFs), which consist of two major components. 

Glozak MA, Seto E (2009) Acetylation/deacetylation modulates the stability of DNA replication licensing factor Cdtl. J Biol Chem 284(17) 11446-11453... 

Reflect and Apply What are replication licensing factors How did they get their name ... 

Replication licensing factors (RLFs) are proteins that bind to eukaryotic DNA. They get their name from the fact that replication cannot proceed until they are bound. Some of the RLF proteins have been found to be cytosolic. They have access to the chromosome only when the nuclear membrane dissolves during mitosis. Until they are bound, replication cannot occur. This property links eukaryotic DNA replication and the cell cycle. Once RLFs have bound, the DNA is then competent for replication. 

Because eukaryotic cells have multiple chromosomes, it is vital that exactly one copy of the DNAin each be synthesized before the cell divides. This is achieved through a combination of replication licensing, which ensures that DNA synthesis is tightly coupled to passage of cells through the cell cycle, and a series of checkpoints in the cell cycle, at which the integrity of chromosomal DNA is evaluated. 

Env sequences both temporally and between patients. Two drugs that target HIV-1 entry, enfuvirtide and maraviroc, are now licensed for treatment of HIV-1 infection. The efficacy of these drugs validates entry as a point of intervention in viral hfe cycles and, in the context of HIV treatment, contributes to the growing armamentarium of antivirals which, in multidrug combinations, can effectively inhibit viral replication and prevent disease progression. 

The first rotavirus vaccine was a tetravalent rhesus rotavirus strain. It was licensed in the United States in 1998 and subsequently withdrawn from the market due to an association with intussusception. A pentavalent human-bovine reassortant rotavirus vaccine was approved by the FDA in February 2006. The exact mechanism by which the vaccine produces an immune response is unknown however, this live virus vaccine replicates in the small intestines and induces immunity. 

During cell division, a replication-competent state is established at the replication start sites, the pre-RC. This contains the ORC, the MCM proteins and the cdc6 protein. Formation of the pre-RC in late M phase and in G1 phase licenses the chromatin for DNA replication. With entry into S phase, the MCM proteins and the Cdc6 protein dissociate from the start site. Their phosphorylation by an active S phase cyclin-CDK complex is responsible for the dissociation. 

One or more of the proteins that bind to the ORC may constitute a license to replicate. The licensing... 

Lagace had completed the two-and-a half-year Funeral Services program at Flumber College in Ontario and in 1979 obtained his diploma and Ontario license. In 1983 he obtained his Alberta license. He has cremated more than 1,000 bodies. In clear testimony Lagace meticulously explained the problems of cremation and the hazards involved. He showed, in replicable and verifiable manner, that the (coal-stoked ) crematoria of Birkenau were less efficient than crematoria using natural-gas burners (where power can be simply shut off). He was also familiar with the plans for the Birkenau crematoria and compared them to the similar facilities in Bow Valley. 

Da-Silva LF, Duncker BP. ORC function in late Gl maintaining the license for DNA replication. Cell Cycle 2007 6 128-130. DePamphilis ML. The ORC cycle a novel pathway for regulating eukaryotic DNA replication. Gene 2003 310 1-15. 

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