Killer toxin Kp4 family

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Kp4
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structure and function of a virally encoded fungal toxin from ustilago maydis: a fungal and mammalian calcium channel inhibitor
Identifiers
SymbolKp4
Pfam PF09044
InterPro IPR015131

In molecular biology, the killer toxin Kp4 family is a family of killer toxins, which includes the Kp4 killer toxin from the smut fungus Ustilago maydis . [1]

Killer toxins are polypeptides secreted by some fungal species ("killer yeasts") that kill sensitive cells of the same or related species, often functioning by creating pores in target cell membranes. The fungal killer toxin KP4 from the corn smut fungus, Ustilago maydis (Smut fungus), is encoded by a resident symbiotic double-stranded RNA virus, Ustilago maydis P4 virus (UmV4), within fungal cells. Unlike most killer toxins, KP4 is a single polypeptide. [1] KP4 inhibits voltage-gated calcium channels in mammalian cells, which in turn inhibits cell growth and division by blocking calcium import. KP4 adopts a structure consisting of a two-layer alpha/beta sandwich with a left-handed crossover. [2]

Related Research Articles

Corn smut A fungal plant disease on maize and teosint

Corn smut is a plant disease caused by the pathogenic fungus Ustilago maydis that causes smut on maize and teosinte. The fungus forms galls on all above-ground parts of corn species. It is edible, and is known in Mexico as the delicacy huitlacoche; which is eaten, usually as a filling, in quesadillas and other tortilla-based foods, and in soups.

Smut (fungus) Reproductive structure of fungi

The smuts are multicellular fungi characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled, and dust-like teliospores. They are mostly Ustilaginomycetes and can cause plant disease. The smuts are grouped with the other basidiomycetes because of their commonalities concerning sexual reproduction.

<i>Ustilago</i> Genus of fungi

Ustilago is a genus of approximately 200 smut fungi parasitic on grasses.

Itaconic acid Chemical compound

Itaconic acid, or methylidenesuccinic acid, is an organic compound. This dicarboxylic acid is a white solid that is soluble in water, ethanol, and acetone. Historically, itaconic acid was obtained by the distillation of citric acid, but currently it is produced by fermentation. The name itaconic acid was devised as an anagram of aconitic acid, another derivative of citric acid.

<i>Herpesviridae</i> Family of DNA viruses

Herpesviridae is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word herpein 'to creep', referring to spreading cutaneous lesions, usually involving blisters, seen in flares of herpes simplex 1, herpes simplex 2 and herpes zoster (shingles). In 1971, the International Committee on the Taxonomy of Viruses (ICTV) established Herpesvirus as a genus with 23 viruses among four groups. As of 2020, 115 species are recognized, all but one of which are in one of the three subfamilies. Herpesviruses can cause both latent or lytic infections.

Mating in fungi Combination of genetic material between compatible mating types

Mating in fungi is a complex process governed by mating types. Research on fungal mating has focused on several model species with different behaviour. Not all fungi reproduce sexually and many that do are isogamous; thus, the terms "male" and "female" do not apply to many members of the fungal kingdom. Homothallic species are able to mate with themselves, while in heterothallic species only isolates of opposite mating types can mate.

Taicatoxin (TCX) is a snake toxin that blocks voltage-dependent L-type calcium channels and small conductance Ca2+-activated K+ channels. The name taicatoxin (TAIpan + CAlcium + TOXIN) is derived from its natural source, the taipan snake, the site of its action, calcium channels, and from its function as a toxin. Taicatoxin was isolated from the venom of Australian taipan snake, Oxyuranus scutellatus scutellatus. TCX is a secreted protein, produced in the venom gland of the snake.

Calciseptine

Calciseptine (CaS) is a natural neurotoxin isolated from the black mamba Dendroaspis p. polylepis venom. This toxin consists of 60 amino acids with four disulfide bonds. Calciseptine specifically blocks L-type calcium channels, but not other voltage-dependent Ca2+ channels such as N-type and T-type channels.

Mycovirus


Mycoviruses, also known as mycophages, are viruses that infect fungi. The majority of mycoviruses have double-stranded RNA (dsRNA) genomes and isometric particles, but approximately 30% have positive-sense, single-stranded RNA (+ssRNA) genomes.

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Dimorphic fungus

Dimorphic fungi are fungi that can exist in the form of both mold and yeast. This is usually brought about by change in temperature and the fungi are also described as thermally dimorphic fungi. An example is Talaromyces marneffei, a human pathogen that grows as a mold at room temperature, and as a yeast at human body temperature.

Double-stranded RNA viruses Type of virus according to Baltimore classification

Double-stranded RNA viruses are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. The double-stranded genome is used to transcribe a positive-strand RNA by the viral RNA-dependent RNA polymerase (RdRp). The positive-strand RNA may be used as messenger RNA (mRNA) which can be translated into viral proteins by the host cell's ribosomes. The positive-strand RNA can also be replicated by the RdRp to create a new double-stranded viral genome.

A killer yeast is a yeast, such as Saccharomyces cerevisiae, which is able to secrete one of a number of toxic proteins which are lethal to susceptible cells. These "killer toxins" are polypeptides that kill sensitive cells of the same or related species, often functioning by creating pores in target cell membranes. These yeast cells are immune to the toxic effects of the protein due to an intrinsic immunity. Killer yeast strains can be a problem in commercial processing because they can kill desirable strains. The killer yeast system was first described in 1963. Study of killer toxins helped to better understand the secretion pathway of yeast, which is similar to those of more complex eukaryotes. It also can be used in treatment of some diseases, mainly those caused by fungi.

Fungus Biological kingdom, separate from plants and animals

A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, those being Plantae, Animalia, Protozoa, and Chromista.

Antiviral protein

Antiviral proteins are proteins that are induced by human or animal cells to interfere with viral replication. These proteins are isolated to inhibit the virus from replicating in a host's cells and stop it from spreading to other cells. The Pokeweed antiviral protein and the Zinc-Finger antiviral protein are two major antiviral proteins that have undergone several tests for viruses, including HIV and influenza.

Lolitrem B Chemical compound

Lolitrem B is one of many toxins produced by a fungus called Epichloë festucae, which grows in perennial ryegrass. The fungus is symbiotic with the ryegrass; it doesn't harm the plant, and the toxins it produces kill insects that feed on ryegrass. Lolitrem B is one of these toxins, but it is also harmful to mammals. The shoots and flowers of infected ryegrass have especially high concentrations of lolitrem B, and when livestock eat too much of them, they get perennial ryegrass staggers. At low doses the animals have tremors, and at higher doses they stagger, and at higher yet doses the animals become paralyzed and die. The blood pressure of the animals also goes up. The effect of the lolitrem B comes on slowly and fades out slowly, as it is stored in fat after the ryegrass is eaten. The condition is especially common in New Zealand and Australia, and plant breeders there have been trying to develop strains of fungus that produce toxins only harmful to pests, and not to mammals.

Ustilagic acid is an organic compound with the formula C36H64O18. The acid is a cellobiose lipid produced by the corn smut fungus Ustilago maydis under conditions of nitrogen starvation. The acid was discovered in 1950 and was proved to be an amphipathic glycolipid with surface active properties. The name comes from Latin ustus which means burnt and refers to the scorched appearance of the smut fungi.

KP4, Kp4 or kp4 may refer to

Regine KahmannRegine Kahmann is a German microbiologist and was Director at the Max Planck Institute for Terrestrial Microbiology in Marburg from 2000-2019. She was made a Foreign Member of the Royal Society (ForMRS) in 2020.

References

  1. 1 2 Park CM, Bruenn JA, Ganesa C, Flurkey WF, Bozarth RF, Koltin Y (January 1994). "Structure and heterologous expression of the Ustilago maydis viral toxin KP4". Mol. Microbiol. 11 (1): 155–64. doi:10.1111/j.1365-2958.1994.tb00297.x. PMID   8145639.
  2. Gu F, Khimani A, Rane SG, Flurkey WH, Bozarth RF, Smith TJ (August 1995). "Structure and function of a virally encoded fungal toxin from Ustilago maydis: a fungal and mammalian Ca2+ channel inhibitor". Structure. 3 (8): 805–14. doi: 10.1016/s0969-2126(01)00215-5 . PMID   7582897.
This article incorporates text from the public domain Pfam and InterPro: IPR015131