hERG ( the human Ether-à-go-go-Related Gene ) is a gene () that codes for a protein known as K < sub > v </ sub > 11. 1, the alpha subunit of a potassium ion channel.

The hERG gene was first named and described in a paper by Jeff Warmke and Barry Ganetzky, then both at the University of Wisconsin.

This ion channel ( sometimes simply denoted as ' hERG ') is best known for its contribution to the electrical activity of the heart that coordinates the heart's beating ( i. e., the hERG channel mediates the repolarizing I < sub > Kr </ sub > current in the cardiac action potential ).

When this channel's ability to conduct electrical current across the cell membrane is inhibited or compromised, either by application of drugs or by rare mutations in some families, it can result in a potentially fatal disorder called long QT syndrome ; a number of clinically successful drugs in the market have had the tendency to inhibit hERG, and create a concomitant risk of sudden death, as a side-effect, which has made hERG inhibition an important antitarget that must be avoided during drug development.

hERG forms the major portion of one of the ion channel proteins ( the ' rapid ' delayed rectifier current ( I < sub > Kr </ sub >)) that conducts potassium ( K < sup >+</ sup >) ions out of the muscle cells of the heart ( cardiac myocytes ), and this current is critical in correctly timing the return to the resting state ( repolarization ) of the cell membrane during the cardiac action potential.

Sometimes, when referring to the pharmacological effects of drugs, the terms " hERG channels " and I < sub > Kr </ sub > are used interchangeably, but, in the technical sense, " hERG channels " can be made only by scientists in the laboratory ; in formal terms, the naturally-occurring channels in the body that include hERG are referred to by the name of the electrical current that has been measured in that cell type, so, for example, in the heart, the correct name is I < sub > Kr </ sub >.

This difference in nomenclature becomes clearer in the controversy as to whether the channels conducting I < sub > Kr </ sub > include other subunits ( e. g., beta subunits < ref > ) or whether the channels include a mixture of different types ( isoforms ) of hERG ,< ref > but, when the originally-discovered form of hERG is experimentally transferred into cells that previously lacked hERG ( i. e., heterologous expression ), a potassium ion channel is formed, and this channel has many signature features of the cardiac ' rapid ' delayed rectifier current ( I < sub > Kr </ sub >),< ref name =" Sanguinetti_ 1995 "> including I < sub > Kr </ sub >' s inward rectification that results in the channel producing a ' paradoxical resurgent current ' in response to repolarization of the membrane.

A detailed atomic structure for hERG based on X-ray cystallography is not yet available, so structural details for hERG are based on analogy with other ion channels, computer models, pharmacology, and mutagenesis studies.

Between the S5 and S6 helices, there is an extracellular loop ( known as ' the turret ') and ' the pore loop ', which begins and ends extracellularly but loops into the plasma membrane ; the pore loop for each of the hERG subunits in one channel face into the ion-conducting pore and are adjacent to the corresponding loops of the 3 other subunits, and together they form the selectivity filter region of the channel pore.

Although a full crystal structure for hERG is not yet available, a structure has been found for the cytoplasmic N-terminus, which was shown to contain a PAS domain ( aminoacid 26-135 ) that slows the rate of deactivation.

One of the main reasons for this phenomenon is the larger inner vestibule of the hERG channel, thus providing more space for many different drug classes to bind and block this potassium channel.

hERG has also been associated with modulating the functions of some cells of the nervous system and with establishing and maintaining cancer-like features in leukemic cells.

In the laboratory the heterologously expressed hERG potassium channel comprises 4 identical alpha subunits, which form the channel's pore through the plasma membrane.

Each hERG subunit consists of 6 transmembrane alpha helices, numbered S1-S6, a pore helix situated between S5 and S6, and cytoplasmically located N-and C-termini.

There are far more hERG mutations described for long QT syndrome than for short QT syndrome.

Although there exist other potential targets for cardiac adverse effects, the vast majority of drugs associated with acquired QT prolongation are known to interact with the hERG potassium channel.

It was shown that sorghum's aluminium tolerance is controlled by a single gene, as for wheat.

One candidate gene with polymorphisms that influence anxiety is PLXNA2.

Wilson's disease is an autosomal-recessive gene disorder whereby an alteration of the ATP7B gene results in an inability to properly excrete copper from the body.

An allele ( or ) is one of two or more forms of a gene or a genetic locus ( generally a group of genes ).

The word " allele " is a short form of allelomorph (' other form '), which was used in the early days of genetics to describe variant forms of a gene detected as different phenotypes.

It is now appreciated that most or all gene loci are highly polymorphic, with multiple alleles, whose frequencies vary from population to population, and that a great deal of genetic variation is hidden in the form of alleles that do not produce obvious phenotypic differences.

Other disorders are also due to recessive alleles, but because the gene locus is located on the X chromosome, so that males have only one copy ( that is, they are hemizygous ), they are more frequent in males than in females.

An ampicillin resistance gene ( abbreviated ampR ) is commonly used as a selectable marker in routine biotechnology.

The large and diverse population of antibodies is generated by random combinations of a set of gene segments that encode different antigen binding sites ( or paratopes ), followed by random mutations in this area of the antibody gene, which create further diversity.

MAC, also called " Mitochondrial Outer Membrane Permeabilization Pore " is regulated by various proteins, such as those encoded by the mammalian Bcl-2 family of anti-apoptopic genes, the homologs of the ced-9 gene found in C. elegans.

Since a -/- mutation in the APAF-1 gene is embryonic lethal, a gene trap strategy was used in order to generate an APAF-1 -/- mouse.

This assay is used to disrupt gene function by creating an intragenic gene fusion.

When an APAF-1 gene trap is introduced into cells, many morphological changes occur, such as spina bifida, the persistence of interdigital webs, and open brain.

It is the most polyphetic known enzyme: six distinct classes have been described, all catalyzing the same reaction but representing unrelated gene families with no known sequence or structural homology.

Albinism results from inheritance of recessive gene alleles and is known to affect all vertebrates, including humans.

The truncated myostatin gene is unable to function in its normal capacity, resulting in accelerated lean muscle growth.

This particular type of growth is seen early in the fetus of a pregnant dam, which results in a calf that is born with two times the number of muscle fibers at birth than a calf with no myostatin gene mutation.

Another significant historic event in biochemistry is the discovery of the gene and its role in the transfer of information in the cell.

* Argininosuccinate lyase, human gene making the protein argininosuccinate lyase

In biomedical research, this work can assist in finding candidates for gene alleles that can cause or influence predisposition to disease in human genetics

A new gene is inserted into an adenovirus vector, which is used to introduce the modified DNA into a human cell.

* Cocksackie Adenovirus Receptor, alternative symbol CAR for the human gene CXADR

According to this research, genetic markers commonly found in modern humans worldwide suggest that today many people carry a gene that evolved as protection against the brain diseases that can be spread by consuming human brain tissue.

* CPD ( gene ), a human gene encoding the protein Carboxypeptidase D

* CPM ( gene ), a human gene encoding the protein carboxypeptidase M

* CIT ( gene ), a human gene that encodes the enzyme Citron Rho-interacting kinase

They recognize individuals who have contributed to human evolution by self-selecting themselves out of the gene pool through putting themselves ( unnecessarily ) in life-threatening situations.

* Prostaglandin E2 receptor, a human gene

Genetic evidence has also been employed to resolve the question of whether there was any gene flow between early modern humans and Neanderthals, and to arrive enhance our understanding of the early human migration patterns and splitting dates.

* Ferritin light chain, a human gene that encodes the light subunit of the ferritin protein

Changes in an environmental variable ( e. g. human nutrition ) may cause different genes to be gene expression | expressed during childhood.

For instance, the human CFTR gene, which encodes a protein that transports chloride ions across cell membranes, can be dominant ( A ) as the normal version of the gene, or recessive ( a ) as a mutated version of the gene.

Other forms involve directly correcting a mutation, or using DNA that encodes a therapeutic protein drug ( rather than a natural human gene ) to provide treatment.

An example of gene-knockout mediated gene therapy is the knockout of the human CCR5 gene in T-cells in order to control HIV infection.

A number of viruses have been used for human gene therapy, including retrovirus, adenovirus, lentivirus, herpes simplex virus, vaccinia, pox virus, and adeno-associated virus.

In November 2006 Preston Nix from the University of Pennsylvania School of Medicine reported on VRX496, a gene-based immunotherapy for the treatment of human immunodeficiency virus ( HIV ) that uses a lentiviral vector for delivery of an antisense gene against the HIV envelope.

These studies, which used adeno-associated virus, have spawned a number of new studies investigating gene therapy for human retinal disease.