| Paramyxovirus | ||||||
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| Genera | ||||||
Subfamily Paramyxovirinae |
Paramyxoviruses are viruses of the Paramyxoviridae family of the Mononegavirales order; they are negative-sense single-stranded RNA viruses responsible for a number of human and animal diseases. Virus classification involves naming and placing Viruses into a taxonomic system An RNA virus is a Virus that has RNA (ribonucleic acid as its Genetic material. The Mononegavirales are an order of Viruses comprising species that have a Non-segmented, negative sense RNA Genome The Genus Avulavirus is one of eight genera in the family Paramyxoviridae and contains viruses that used to be classified in the genus Rubulavirus, Henipavirus is a Genus of the family Paramyxoviridae, order Mononegavirales containing two members Hendravirus Morbillivirus is a genus belonging to the Paramyxoviridae family of Viruses in the order Mononegavirales. Rubulavirus is a genus of the Paramyxoviridae family of infectious Viruses The genus includes the Mumps virus and parainfluenza type 2 4a and Human metapneumovirus (hMPV was isolated for the first time in 2001 in the Netherlands by using the RAP-PCR (RNA arbitrarily primed PCR) technique for identification of A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable The Mononegavirales are an order of Viruses comprising species that have a Non-segmented, negative sense RNA Genome An RNA virus is a Virus that has RNA (ribonucleic acid as its Genetic material. Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly
Contents |
Genera
- Subfamily Paramyxovirinae
- Genus Avulavirus (type species Newcastle disease virus)
- Genus Henipavirus (type species Hendravirus; others include Nipahvirus)
- Genus Morbillivirus (type species Measles virus; others include Rinderpest virus, Canine distemper virus, phocine distemper virus)
- Genus Respirovirus (type species Sendai virus; others include Human parainfluenza viruses 1 and 3, as well some of the viruses of the common cold)
- Genus Rubulavirus (type species Mumps virus; others include Simian parainfluenza virus 5, Menangle virus, Tioman virus)
- Genus TPMV-like viruses (type species Tupaia paramyxovirus)
- Subfamily Pneumovirinae
- Genus Pneumovirus (type species Human respiratory syncytial virus, others include Bovine respiratory syncytial virus)
- Genus Metapneumovirus (type species Avian pneumovirus, Human metapneumovirus)
- Unassigned viruses
- Fer-de-Lance virus
- Nariva virus
- Tupaia paramyxovirus
- Salem virus
- J virus
- Mossman virus
- Beilong virus
Physical structure
Virions are enveloped and can be spherical, filamentous or pleomorphic. The Genus Avulavirus is one of eight genera in the family Paramyxoviridae and contains viruses that used to be classified in the genus Rubulavirus, Newcastle disease is a highly contagious Zoonotic Bird Disease affecting many domestic and wild avian species Henipavirus is a Genus of the family Paramyxoviridae, order Mononegavirales containing two members Hendravirus Henipavirus is a Genus of the family Paramyxoviridae, order Mononegavirales containing two members Hendravirus Henipavirus is a Genus of the family Paramyxoviridae, order Mononegavirales containing two members Hendravirus Morbillivirus is a genus belonging to the Paramyxoviridae family of Viruses in the order Mononegavirales. Measles (rubeola is a Disease caused by a virus specifically a Paramyxovirus of the genus Morbillivirus. Rinderpest is an infectious viral Disease of Cattle, domestic buffalo, and some Species of Wildlife. Canine distemper is a very serious viral Disease affecting animals in the families Canidae, Mustelidae, Mephitidae, Hyaenidae Phocine distemper virus (PDV is a Paramyxovirus of the genus Morbillivirus that is pathogenic for Pinniped species particularly seals Sendai virus (SeV also known as murine parainfluenza virus type 1 is a negative sense single-stranded RNA Virus of the Paramyxoviridae Human parainfluenza viruses (HPIVs are a group of four distinct Serotypes of single-stranded RNA Viruses belonging to the Paramyxovirus Acute viral nasopharyngitis or acute coryza, usually known as the common cold, is a highly contagious viral Infectious disease of the Rubulavirus is a genus of the Paramyxoviridae family of infectious Viruses The genus includes the Mumps virus and parainfluenza type 2 4a and Mumps or epidemic Parotitis is a Viral disease of the Human species Menangle virus is a virus that infects Pigs Humans and Bats It was first identified in 1997 after a piggery in Menangle near Sydney Tioman virus is a Paramyxovirus first isolated from the urine of island Fruit bats ( Pteropus hypomelanus) on Tioman Island, Malaysia Human respiratory syncytial virus (RSV is a negative-sense single-stranded RNA virus of the family Paramyxoviridae, which includes Human metapneumovirus (hMPV was isolated for the first time in 2001 in the Netherlands by using the RAP-PCR (RNA arbitrarily primed PCR) technique for identification of Fusion proteins and attachment proteins appear as spikes on the virion surface. Matrix proteins inside the envelope stabilise virus structure. The nucleocapsid core is composed of the genomic RNA, nucleocapsid proteins, phosphoproteins and polymerase proteins.
Genome structure
The genome consists of a single segment of negative-sense RNA, 15-19 kilobases in length and containing 6-10 genes. In classical genetics the genome of a Diploid Organism including Eukarya refers to a full set of chromosomes or genes in a Gamete, thereby Extracistronic (non-coding) regions include:
- A 3’ leader sequence, 50 nucleotides in length which acts as a transcriptional promoter. Nucleotides are Organic compounds that consist of three joined structures a nitrogenous base a Sugar, and a Phosphate group Transcription is the synthesis of RNA under the direction of DNA
- A 5’ trailer sequence, 50-161 nucleotides long
- Intergenomic regions between each gene which are three nucleotides long for morbillivirus, respirovirus and henipavirus, variable length (1-56 nucleotides) for rubulavirus and pneumovirinae. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance
Each gene contains transcription start/stop signals at the beginning and end which are transcribed as part of the gene.
Gene sequence within the genome is conserved across the family due to a phenomenon known as transcriptional polarity (see Mononegavirales) in which genes closest to the 3’ end of the genome are transcribed in greater abundance than those towards the 5’ end. The Mononegavirales are an order of Viruses comprising species that have a Non-segmented, negative sense RNA Genome This mechanism acts as a form of transcriptional regulation.
The gene sequence is:
- Nucleocapsid – Phosphoprotein – Matrix – Fusion – Attachment – Large (polymerase)
Proteins
- N – the nucleocapsid protein associates with genomic RNA (one molecule per hexamer) and protects the RNA from nuclease digestion
- P – the phosphoprotein binds to the N and L proteins and forms part of the RNA polymerase complex
- M – the matrix protein assembles between the envelope and the nucleocapsid core, it organizes and maintains virion structure
- F – the fusion protein projects from the envelope surface as a trimer, and mediates cell entry by inducing fusion between the viral envelope and the cell membrane by class I fusion. Chronic since 1992 ( talk) 2200 12 December 2007 (UTC --> Viral entry One of the defining characteristics of members of the paramyxoviridae family is the requirement for a neutral pH for fusogenic activity.
- H/HN/G – the cell attachment proteins span the viral envelope and project from the surface as spikes. They bind to sialic acid on the cell surface and facilitate cell entry. Note that the receptor for measles virus is unknown. Proteins are designated H for morbilliviruses and henipaviruses as they possess haemagglutination activity, observed as an ability to cause red blood cells to clump. HN attachment proteins occur in respiroviruses and rubulaviruses. These possess both haemagglutination and neuraminidase activity which cleaves sialic acid on the cell surface, preventing viral particles from reattaching to previously infected cells. Attachment proteins with neither haemagglutination nor neuraminidase activity are designated G (glycoprotein). Not to be confused with Peptidoglycan. Glycoproteins are proteins that contain Oligosaccharide chains ( Glycans) covalently attached These occur in members of pneumovirinae.
- L – the large protein is the catalytic subunit of RNA dependent RNA polymerase (RDRP)
- Accessory proteins – a mechanism known as RNA editing (see Mononegavirales) allows multiple proteins to be produced from the P gene. The Mononegavirales are an order of Viruses comprising species that have a Non-segmented, negative sense RNA Genome These are not essential for replication but may aid in survival in vitro or may be involved in regulating the switch from mRNA synthesis to antigenome synthesis.
Pathogenic paramyxoviruses
A number of important human diseases are caused by paramyxoviruses. These include mumps, measles, which caused 745,000 deaths in 2001 and respiratory syncytial virus (RSV) which is the major cause of bronchiolitis and pneumonia in infants and children. Mumps or epidemic Parotitis is a Viral disease of the Human species Measles (rubeola is a Disease caused by a virus specifically a Paramyxovirus of the genus Morbillivirus. Human respiratory syncytial virus (RSV is a negative-sense single-stranded RNA virus of the family Paramyxoviridae, which includes Bronchiolitis is inflammation of the Bronchioles the smallest air passages of the lungs Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal
The parainfluenza viruses are the second most common causes of respiratory tract disease in infants and children. Human parainfluenza viruses (HPIVs are a group of four distinct Serotypes of single-stranded RNA Viruses belonging to the Paramyxovirus They can cause pneumonia, bronchitis and croup in children and the elderly. Bronchitis is an Inflammation of the Bronchi. More specifically it may refer to Acute bronchitis, caused by viruses or bacteria and lasting Croup is a group of Respiratory diseases that often affect infants and children under age 6
Human metapneumovirus, initially described in about 2001, is also implicated in bronchitis, especially in children.
Paramyxoviruses are also responsible for a range of diseases in other animal species, for example canine distemper virus (dogs), phocine distemper virus (seals), cetacean morbillivirus (dolphins and porpoises) Newcastle disease virus (birds) and rinderpest virus (cattle). Canine distemper is a very serious viral Disease affecting animals in the families Canidae, Mustelidae, Mephitidae, Hyaenidae The dog ( Canis lupus familiaris) is a domesticated Subspecies of the gray wolf, a Mammal of the Canidae family of the order Phocine distemper virus (PDV is a Paramyxovirus of the genus Morbillivirus that is pathogenic for Pinniped species particularly seals Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising Dolphins are Marine mammals that are closely related to Whales and Porpoises There are almost forty species of dolphin in seventeen genera. Porpoises are Small Cetaceans of the Family Phocoenidae; they are related to Whales and Dolphins They are distinct from dolphins Newcastle disease is a highly contagious Zoonotic Bird Disease affecting many domestic and wild avian species Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Rinderpest is an infectious viral Disease of Cattle, domestic buffalo, and some Species of Wildlife. Cattle, colloquially referred to as cows, are domesticated Ungulates a member of the Subfamily Bovinae of the family Some paramyxoviruses such as the henipaviruses are zoonotic pathogens, occurring naturally in an animal host, but also able to infect humans. A zoonosis (ˌzoʊəˈnoʊsɨs or zoonose is any Infectious disease that is able to be transmitted (by a vector) from other Animals both wild and domestic
Hendra virus (HeV) and Nipah virus (NiV) in the genus Henipavirus have emerged in humans and livestock in Australia and Southeast Asia. Henipavirus is a Genus of the family Paramyxoviridae, order Mononegavirales containing two members Hendravirus For a topic outline on this subject see List of basic Australia topics. Both viruses are contagious, highly virulent, and capable of infecting a number of mammalian species and causing potentially fatal disease. Virulence (also called pestiferousness) refers to the degree of Pathogenicity of a Microbe, or in other words the relative ability of a Microbe Due to the lack of a licensed vaccine or antiviral therapies, HeV and NiV are designated as biosafety level (BSL) 4 agents. A vaccine is a biological preparation which is used to establish or improve immunity to a particular disease The genomic structure of both viruses is that of a typical paramyxovirus. [1]
See also
External links
- Paramyxoviruses (1998) — morphology, genome, replication, pathogenesis
- Hendra virus has a growing family tree (2001) CSIRO Paramyxovirus press release
- Animal viruses
References
- ^ Sawatsky et al (2008). The study of animal viruses is important from a veterinary viewpoint and many of these viruses cause diseases that are economically devastating Virology is the study of viruses and virus-like agents: their structure classification and evolution their ways to infect and exploit cells for virus reproduction Henipavirus is a Genus of the family Paramyxoviridae, order Mononegavirales containing two members Hendravirus "Hendra and Nipah Virus", Animal Viruses: Molecular Biology. Caister Academic Press. ISBN 978-1-904455-22-6.
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