Syncytin is a captive retroviral envelope protein involved in human placental morphogenesis

@article{Mi2000SyncytinIA,
  title={Syncytin is a captive retroviral envelope protein involved in human placental morphogenesis},
  author={Sha Mi and Xinhua Lee and Xiangping Li and G. M. Veldman and Heather F. Finnerty and Lisa A. Racie and Edward R. Lavallie and Xiang-Yang Tang and Philippe Edouard and Steve Howes and James C. Keith and John M. Mccoy},
  journal={Nature},
  year={2000},
  volume={403},
  pages={785-789}
}
Many mammalian viruses have acquired genes from their hosts during their evolution. The rationale for these acquisitions is usually quite clear: the captured genes are subverted to provide a selective advantage to the virus. Here we describe the opposite situation, where a viral gene has been sequestered to serve an important function in the physiology of a mammalian host. This gene, encoding a protein that we have called syncytin, is the envelope gene of a recently identified human endogenous… 
The Role of Endogenous Retroviruses in the Formation of Syncytiotrophoblast and Materno-Fetal Barrier
TLDR
It appears that as a result of convergent evolution, the protein products of independently acquired syncytin genes fulfill a similar physiological function in primate and rodent lineages.
Placental syncytins: Genetic disjunction between the fusogenic and immunosuppressive activity of retroviral envelope proteins
TLDR
The results unravel a critical function of retroviral envelopes, not necessarily “individually” selected for in the retrovirus endogenization process, albeit “tandemly” conserved in evolution for the syncytin pairs in primates and Muridae.
Syncytins: Molecular Aspects
TLDR
The biological functions ofsyncytins and the regulation of syncytin gene expression at the molecular level are provided and the pathological functions of synCytins are also discussed.
Endogenous retroviral syncytin: compilation of experimental research on syncytin and its possible role in normal and disturbed human placentogenesis.
TLDR
Findings indicate an involvement of syncytin in the development of the human placenta and that it may also have played an important role in human placental evolution.
Syncytin-A knockout mice demonstrate the critical role in placentation of a fusogenic, endogenous retrovirus-derived, envelope gene
TLDR
It is demonstrated that syncytin-A is essential for trophoblast cell differentiation and syncytiotrophoblast morphogenesis during placenta development, and they provide evidence that genes captured from ancestral retroviruses have been pivotal in the acquisition of new, important functions in mammalian evolution.
Syncytin-2 plays an important role in the fusion of human trophoblast cells.
Retroviral Endogenization and Its Role in the Genital Tract during Mammalian Evolution
TLDR
This review presents ERVs and related but distinct fusogenic and non-fusogenic genes, and proposes the “baton pass” hypothesis, in which a new gene such as one of the ERVs replaced a pre-existing gene and acquired the role that gene had played, accounting for time differences between ERVs endogenization and placental evolution.
Implication of Human Endogenous Retrovirus Envelope Proteins in Placental Functions
TLDR
Recent findings are summarized showing that two ERV genes, termed Syncytin-1 and Syncytn-2, which encode former envelope (Env) proteins, trigger fusion events between villous cytotrophoblasts and the peripheral multinucleated syncytiotrophoblast layer, which maintains the stability of this latter cell structure.
Influenza A virus transactivates the mouse envelope gene encoding syncytin B and its regulator, glial cells missing 1
TLDR
The authors report that influenza A virus infection increased the levels of transcripts encoding Gcm1 andsyncytin B, but not syncytin A, in NIH-3T3 cells as well as in mouse primary neurons or glia.
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