cORF has a Rev-like function and, together with the RcRE element, stabilizes unspliced and incompletely spliced viral transcripts and enhances their nuclear export via the CRM1 pathway.
HTDV/HERV-K is identified as the only endogenous retrovirus family with complex posttranscriptional regulation, acting as a potential evolutionary intermediate between simple and complex retroviruses.
cORF, a protein encoded by the human endogenous retrovirus family HTDV/HERV-K, contains amino acid motifs which resemble the nuclear import and export signals of the viral regulatory proteins Rev (human immunodeficiency virus) and Rex (human T-cell leukemia virus HTLV). In this study, we demonstrated that cORF indeed has a Rev-like function and mapped the cORF-responsive RNA element to a sequence in the 3' long terminal repeat, a localization similar to RxRE, the responsive element in HTLV type 1. Accordingly, we have given the element the designation RcRE. cORF and RcRE stabilize unspliced and incompletely spliced viral transcripts and enhance their nuclear export via the CRM1 export pathway. So far, HTDV/HERV-K is the only endogenous retrovirus family with a complex regulation at the posttranscriptional level. It may be regarded as an intermediate in the evolution from simple to complex retroviruses.
Magin et al. (Mon,) conducted a other in Human Endogenous Retrovirus Family HTDV/HERV-K. cORF and RcRE was evaluated on cORF function and RcRE localization. cORF has a Rev-like function and, together with the RcRE element, stabilizes unspliced and incompletely spliced viral transcripts and enhances their nuclear export via the CRM1 pathway.