Human T-lymphotropic virus 1: Difference between revisions
Kmagalhaes (talk | contribs) No edit summary |
Kmagalhaes (talk | contribs) |
||
Line 16: | Line 16: | ||
==Genome structure== | ==Genome structure== | ||
HTLV-1 contains a linear, dimeric, ssRNA(+) genome of 8,507nt , with a 5’-cap and a 3’poly-A tail. There are two long terminal repeats (LTRs) of about 600nt long at the 5’ and 3’ ends that contain the U3, R, and U5 regions. There is also a primer binding site (PBS) at the 5’end and a polypurine tract (PPT) at the 3’end. | HTLV-1 contains a linear, dimeric, ssRNA(+) genome of 8,507nt , with a 5’-cap and a 3’poly-A tail. There are two long terminal repeats (LTRs) of about 600nt long at the 5’ and 3’ ends that contain the U3, R, and U5 regions. There is also a primer binding site (PBS) at the 5’end and a polypurine tract (PPT) at the 3’end. In addition to the essential viral genes gag, pol, and env, HTLV-1 encodes regulatory and accessory genes for the pX region open reading frames (ORFs) found in the 3’ portion of the viral genome. ORFs IV and III encode the Tax and Rex regulatory proteins, respectively. Tax activates transcription initiation from the viral promoter in the U3 region of the long terminal repeat, and Rex regulates viral gene expression post-transcriptionally by facilitating the cytoplasmic expression of the incompletely spliced viral mRNAs. | ||
==Cell structure and metabolism== | ==Cell structure and metabolism== | ||
Interesting features of cell structure; how it gains energy; what important molecules it produces. | Interesting features of cell structure; how it gains energy; what important molecules it produces. |
Revision as of 00:00, 15 December 2008
A Microbial Biorealm page on the genus Human T-lymphotropic virus 1
Classification
Higher order taxa
Viruses; Retro-transcribing viruses; Retroviridae; Orthoretrovirinae; Deltaretrovirus; Primate T-lymphotropic Virus-1; Human T-lymphotropic Virus-1
Species
Human T-lymphotropic virus 1 (HTLV-1) is divided into 4 subtypes: A) Cosmopolitan B) Central African Group C) Melanesian Group D) New Central African Group
Description and significance
HTLV-1 is a retrovirus that has infected 20 million people worldwide, and is considered the first retrovirus to be causal for Adult T-cell leukemia (ATL). The HTLV-1 virus contains an enveloped virion that is spherical to pleiomorphic and is about 80-100nm in diameter. Transmission occurs through perinatal transmission by blood or breast milk, sexual transmission, or exposure to contaminated blood products. The infectivity of HTLV-1 is tightly cell-associated, and is mediated through a viral synapse, which suggests that the cell-free virus is largely non-infectious. Tax, a viral oncoprotein, is needed to initiate cellular transformation because HTLV-1 does not use viral capture of a cellular proto-oncogene for oncogenesis. Tax transforms cells through various mechanisms, including the creation of chromosomal instability, the amplification of centrosomes, the abrogation of DNA repair, the activation of cyclin-dependent kinases, and the silencing of p53 and spindle assembly checkpoints.
Genome structure
HTLV-1 contains a linear, dimeric, ssRNA(+) genome of 8,507nt , with a 5’-cap and a 3’poly-A tail. There are two long terminal repeats (LTRs) of about 600nt long at the 5’ and 3’ ends that contain the U3, R, and U5 regions. There is also a primer binding site (PBS) at the 5’end and a polypurine tract (PPT) at the 3’end. In addition to the essential viral genes gag, pol, and env, HTLV-1 encodes regulatory and accessory genes for the pX region open reading frames (ORFs) found in the 3’ portion of the viral genome. ORFs IV and III encode the Tax and Rex regulatory proteins, respectively. Tax activates transcription initiation from the viral promoter in the U3 region of the long terminal repeat, and Rex regulates viral gene expression post-transcriptionally by facilitating the cytoplasmic expression of the incompletely spliced viral mRNAs.
Cell structure and metabolism
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Ecology
Habitat; symbiosis; contributions to the environment.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Current Research
Enter summarries of the most rescent research here--at least three required
References
Edited by student of Emily Lilly at University of Massachusetts Dartmouth.