Pan troglodytes endogenous retrovirus-1 (PtERV1), or chimpanzee endogenous retrovirus-1 (CERV1), is a

retrovirus A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. Once inside the host cell's cytoplasm, the virus uses its own reverse transcriptase ...

that putatively infected chimpanzees about 4 million years ago, and may have been involved in the process of speciation, making the chimpanzee and human lines diverge. Kaiser ''et al.'' have suggested that TRIM5α may have played a critical role in the human immune defense system about 4 million years ago, when the retrovirus was infecting chimpanzees. While no trace of PtERV1 has yet been found in the human genome, about 130 traces of PtERV1 DNA have been found in the genome of modern chimpanzees. After recreating part of the PtERV1 retrovirus, it was reported that TRIM5α prevents the virus from entering human cells ''in vitro''. While this cellular defense mechanism may have been very useful 4 million years ago when facing a PtERV1 epidemic, it has the side effect of leaving cells more susceptible to attack by the HIV-1 retrovirus. Recently, doubt has been cast over the conclusions made by Kaiser ''et al.'' By using a PtERV1 capsid, which produces higher titer virus-like particles, Perez-Caballero ''et al.'' reported that PtERV1 is not restricted by either human or chimpanzee TRIM5α.

References

{{Taxonbar, from=Q7256613 Gammaretroviruses Chimpanzees Infraspecific virus taxa