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Translesion Synthesis (TLS)

Lesions, or DNA damage, can lead to complications during the replication process. Some proteins, like DNA polymerases that can bypass damage in the DNA, a process known as translesion synthesis (TLS). These TLS DNA polymerases share mainly two ver...

(6-4) photoproducts

One of the DNA lesions caused by UV-damage. It has a major impact on the structure of the DNA helix. This type of damage is mostly formed by CT or CC next to each other in the DNA. Pol eta has been reported unable to pass this lesion but has a hig...

Artificial chromosomes

Artificial chromosomes are advanced vectors, they have inserted elements to emulate chromosomes in different model organisms. Since the chromosomes in the model organisms are quite different the vectors contain specific elements for each specific ...

Blotting

Blotting is the act of transferring a sample, via a membrane, from one place to another. The transfer can be accomplished either with an electric current that attracts molecules to the anode, or by touching growing colonies with a membrane to tran...

Cell cycle definition

The cell cycle can be defined as the lifetime of a cell. Throughout its life the cell ages by passing through different phases. The progression from one phase to the next are called checkpoints and are highly regulated by specific proteins working...

Checkpoints

Checkpoints are crucial events in a cells life that are highly regulated. The checkpoints prevent the cell from losing control of its genetic material and lead to cancer cells or induced cell death. These transgressions are regulated by the con...

Cloning vectors

Cloning vectors are used for the purpose of multiplying a gene in a host cell. For the vector to be multiplied it needs to be transcribed within the host. The following features are added to enable amplification of the DNA: 1. DNA backbone - th...

Constitutive expression

Constitutive expression is the ability for a vector to constantly produce the inserted protein. The feature is dependent on the promoter controlling the insert.

Cosmids

Plasmid containing cos sequences which are cohesive ends that are needed for packing the DNA into phage heads from phage lambda. The cosmids can replicate as plasmids in other organisms if the right origin of replication (ori) is added.

Cyclobutane pyrimidine dimers (CPDs)

CPDs can form when two pyrimidine nucleotides (C or T) next to each other in the DNA are exposed to UV-light. CPD is the most abundant form of UV-induced damage and it is often not removed from the DNA by repair mechanisms.[1] Pol eta’s ability to...

DNA damage

There are many processes that can damage DNA: 1. Exogenous proceses, like radiation and chemicals 2. Endogenous processed, like a mutation introduced during replication or interference from a free radical produced in the body Damage can...

DNA polymerase eta (DNA polη)

DNA polymerase eta (pol eta) is one of few DNA polymerases that can bypass damage in the DNA during replication. This decreases the risk of greater damage, such as double strand breaks (DSB) if accumulated can ultimately lead to cell death.[1] Pol...

DNA polymerases

DNA polymerases are responsible for bypassing damage in the DNA during replication. If the damage is not bypassed the group of proteins driving the replication process can stall, collapse and cause greater damage, such as double strand breaks (DSB...

DNA repair

Is preformed through a number of mechanisms that maintain the DNA intact and removes damage caused by exogenic or endogenic processes.

DNA replication

The process through which DNA is duplicated into two identical helices just before cell division.

DNA replication fork

The DNA replication fork is a complex of proteins that slide along the DNA upon replication and preforms the actual replication, i.e, analyses each individual nucleotide, couples it with its corresponding nucleotide and polymerises the DNA chain w...

Expression vectors

Expression vectors are used for the purpose of multiplying a specific protein in a host cell. The vector needs to contain the element that enable transcription of the inserted gene, but it also enables translation of it. The following features are...

G0-phase (Gap0-phase)

Most differentiated cells, in multicellular organisms, leave the cell cycle in G1 phase. Because of this the progression stops and the cells survive without dividing again for days, weeks or in some rare cases the whole life time of the organism...

G1-Phase (Gap1-phase)

When a parent cell is duplicated into two daughter cells, the cells enter G1-phase. It is named Gap1-phase because it generates a gap between the cells two main events, replication of the DNA into two identical copies and correct separation of the...

G2-phase (Gap2-phase)

After S-phase the cell enters a second gap-phase, during which the genome is scanned for damage a second time. Since the genome in this phase exists in two copies homologous recombination, which mends DSBs, dominates. Rapidly growing human cell...

Inducible expression

Inducible expression is a feature of a vector where the expression of the insert is induced by an agent that is added at an appropriate time of the experiment.

Low-fidelity DNA polymerases

Low-fidelity DNA polymerases allow for translesion synthesis, the process of overlooking DNA damage during replication and matching the damaged nucleotide with a suitable base pair. These DNA polymerases share two important main characteristi...

M-phase (Mitotc-phase)

Rapidly growing human cells go through M-phase in ~ 30 min

POLH gene

The POLH gene is 40kbp long and contains 11 exons, that generate a 2432bp long mRNA.[1] Unlike in mice, there is no higher incidence of skin cancer in human individuals heterozygous for defective pol eta.[2] The 70 amino acids constituting the C-...

Plasmids

A plasmid is circular extra-chromosomal DNA found in most bacteria, but do also exist in eukaryots such as S. cerevisiae. Plasmids usually contain genes that can be beneficial to pass on to the next generation in certain environments, like antibio...

Replication

Replication is the process of duplicating DNA in preparation for cell division. The replication mechanism in short consist of prying the DNA helix open and one by one polymerizing the DNA strands with the complementary Watson-Crick nucleotides. ...

S-phase (Synthesis-phase)

In S-phase the genome is duplicated in a process called DNA replication. The DNA replication is preformed by a large protein complex collectively called the replication machinery. This machinery opens the DNA, unwinds it, allows DNA polymerase to ...

SDS PAGE

SDS PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) is the process of denaturing and cover proteins in a sample with negative charge, to let them go through a polyacrylamide gel which sorts the proteins according to size and negat...

Shuttle vectors

Shuttle vectors enable expression of genes in different organisms. Since gene recombination is easier in some organisms it is advantageous to be able to manipulate vectors in certain organism. However, when expressing the inserted proteins the pos...

Vectors

A vector is a vehicle in which a gene from one organisms can be transferred into a unicellular organism or a cell form a multicellular organism. By inserting a gene in a self-replicating element it can be used for experimental purposes, as a so ca...

Viral vectors

The viral vectors is circular viral DNA. * genetic marker - for confirming integration into the host genome

Western blot

Transfer of protein samples from a SDS-PAGE, where the samples have been denatured, streched and covede in the negative molecule SDS.

Xeroderma pigmentosum (XP)

In 1968 J.E. Cleaver et al discovered that Xeroderma Pigmentosum (XP) was caused by a defect in a DNA repair mechanism repairing UV-damage. XP is a rare autosomal recessive disorder leading to an early onset of cancer (median age at 1–2 years). It...

Xeroderma pigmentosum variant (XPV)

1979 J.E. Cleaver et al determined that “pigmented xerodermoid” cells could repair the UV- damage tested to determine XP cells at the same level as normal cells.[1] Hence, there was a clear molecular difference from XP cells. The same year, A.R. L...