WRN (gene)
Encyclopedia
WRN is a human
gene
that provides instructions for producing Werner protein, which is a type of enzyme
called a helicase
. Helicase enzymes generally unwind and separate double-stranded DNA
. These activities are necessary before DNA can be copied in preparation for cell division (DNA replication
). Helicase enzymes are also critical for making a blueprint of a gene for protein production, a process called transcription
. Further evidence suggests that Werner protein plays a critical role in repairing DNA
. Overall, this protein helps maintain the structure and integrity of a person's DNA.
The WRN gene is located on the short (p) arm of chromosome 8
between positions 12 and 11.2, from base pair
31,010,319 to base pair 31,150,818.
is caused by mutation
s in the WRN gene. More than 20 mutations in the WRN gene are known to cause Werner syndrome. Many of these mutations result in an abnormally shortened Werner protein. Evidence suggests that the altered protein
is not transported into the cell nucleus
, where it normally interacts with DNA. This shortened protein may also be broken down too quickly, leading to a loss of Werner protein in the cell. Without normal Werner protein in the nucleus, cells cannot perform the tasks of DNA replication, repair, and transcription. Researchers are still determining how these mutations cause the appearance of premature aging seen in Werner syndrome.
with Ku70, PCNA
, DNA-PKcs, P53
, Ku80, Flap structure-specific endonuclease 1
, WRNIP1
, Bloom syndrome protein
and TERF2
.
Human
Humans are the only living species in the Homo genus...
gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
that provides instructions for producing Werner protein, which is a type of enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
called a helicase
Helicase
Helicases are a class of enzymes vital to all living organisms. They are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands using energy derived from ATP hydrolysis.-Function:Many cellular processes Helicases are a...
. Helicase enzymes generally unwind and separate double-stranded DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
. These activities are necessary before DNA can be copied in preparation for cell division (DNA replication
DNA replication
DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts with one double-stranded DNA molecule and produces two identical copies of the molecule...
). Helicase enzymes are also critical for making a blueprint of a gene for protein production, a process called transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
. Further evidence suggests that Werner protein plays a critical role in repairing DNA
DNA repair
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1...
. Overall, this protein helps maintain the structure and integrity of a person's DNA.
The WRN gene is located on the short (p) arm of chromosome 8
Chromosome 8 (human)
Chromosome 8 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 8 spans about 145 million base pairs and represents between 4.5 and 5.0% of the total DNA in cells....
between positions 12 and 11.2, from base pair
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
31,010,319 to base pair 31,150,818.
Related conditions
Werner syndromeWerner syndrome
Werner syndrome is a very rare, autosomal recessive disorder characterized by the appearance of premature aging....
is caused by mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s in the WRN gene. More than 20 mutations in the WRN gene are known to cause Werner syndrome. Many of these mutations result in an abnormally shortened Werner protein. Evidence suggests that the altered protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
is not transported into the cell nucleus
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
, where it normally interacts with DNA. This shortened protein may also be broken down too quickly, leading to a loss of Werner protein in the cell. Without normal Werner protein in the nucleus, cells cannot perform the tasks of DNA replication, repair, and transcription. Researchers are still determining how these mutations cause the appearance of premature aging seen in Werner syndrome.
Interactions
Werner syndrome ATP-dependent helicase has been shown to interactProtein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
with Ku70, PCNA
PCNA
Proliferating Cell Nuclear Antigen, commonly known as PCNA, is a protein that acts as a processivity factor for DNA polymerase δ in eukaryotic cells. It achieves this processivity by encircling the DNA, thus creating a topological link to the genome...
, DNA-PKcs, P53
P53
p53 , is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms, where it regulates the cell cycle and, thus, functions as a tumor suppressor that is involved in preventing cancer...
, Ku80, Flap structure-specific endonuclease 1
Flap structure-specific endonuclease 1
Flap endonuclease 1 is an enzyme that in humans is encoded by the FEN1 gene.-Interactions:Flap structure-specific endonuclease 1 has been shown to interact with Cyclin-dependent kinase 2, EP300, Werner syndrome ATP-dependent helicase, Heterogeneous nuclear ribonucleoprotein A1, Cyclin A2, PCNA,...
, WRNIP1
WRNIP1
ATPase WRNIP1 is an enzyme that in humans is encoded by the WRNIP1 gene.-Interactions:WRNIP1 has been shown to interact with Werner syndrome ATP-dependent helicase.-External links:...
, Bloom syndrome protein
Bloom syndrome protein
Bloom syndrome protein is a protein that in humans is encoded by the BLM gene and is expressed in Bloom syndrome.The Bloom syndrome gene product is related to the RecQ subset of DExH box-containing DNA helicases and has both DNA-stimulated ATPase and ATP-dependent DNA helicase activities...
and TERF2
TERF2
Telomeric repeat-binding factor 2 is a protein that is also known as TRF2 and TRBF2. It is in humans encoded by the TERF2 gene.-Interactions:...
.