HSURs (Herpesvirus saimiri U RNAs) are viral small regulatory RNAs. They are found in Herpesvirus saimiri which is responsible for aggressive T-cell leukemias in primates. They are nuclear RNAs which bind host proteins to form small nuclear ribonucleoproteins (snRNPs). The RNAs are 114–143 nucleotides in length and the HSUR family has been subdivided into HSURs numbered 1 to 7. The function of HSURs has not yet been identified; they do not affect transcription so are thought to act post-transcriptionally, potentially influencing the stability of host mRNAs.
A proposed role for HSURs is that they use the RNA interference (RNAi) pathway to manipulate host-cell gene expression. One identified miRNA which responds to HSURs is miR-27.
12Tycowski K.T., Kolev N.G., Conrad N.K., Fok V., and Steitz J.A. 2006. The ever-growing world of small nuclear ribonucleoproteins. In The RNA world, 3rd edition (ed. R.F. Gesteland et al.), p. 327. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.
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