HSURs (''Herpesvirus saimiri'' U RNAs) are viral small regulatory RNAs. They are found in ''

Herpesvirus saimiri ''Saimiriine gammaherpesvirus 2'' (SaHV-2) is a species of virus in the genus ''Rhadinovirus'', subfamily ''Gammaherpesvirinae'', family ''Herpesviridae'', and order ''Herpesvirales''. See also * HSUR (''Herpesvirus saimiri'' U RNAs) * Squirre ...

'' which is responsible for aggressive T-cell leukemias in

primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...

s. They are nuclear RNAs which bind host

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

s to form small nuclear ribonucleoproteins (snRNPs). The RNAs are 114–143

nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...

s in length and the HSUR family has been subdivided into HSURs numbered 1 to 7.Tycowski 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. 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

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ...

s. HSUR1 and 2 are the most conserved members of the family within HSV subgroups. HSUR1 has been shown to bind the host

heterogeneous ribonucleoprotein particle Heterogeneous nuclear ribonucleoproteins (hnRNPs) are complexes of RNA and protein present in the cell nucleus during transcription (genetics), gene transcription and subsequent post-transcriptional modification of the newly synthesized RNA (pre-mRN ...

protein

hnRNPD Heterogeneous nuclear ribonucleoprotein D0 (HNRNPD) also known as AU-rich element RNA-binding protein 1 (AUF1) is a protein that in humans is encoded by the ''HNRNPD'' gene. Alternative splicing of this gene results in four transcript variants. ...

''in vivo''. Other HSURs bind HuR/ELAVL1. They are transcribed by

RNA polymerase II RNA polymerase II (RNAP II and Pol II) is a multiprotein complex that transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNAP enzymes found in the nucleus of eukaryoti ...

with promoters similar to that of U RNAs Features shared by all HSURs include: * 5′-trimethylguanosine

caps Caps are flat headgear. Caps or CAPS may also refer to: Science and technology Computing * CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters * Composite Application Platform Suite, by Java Caps, a Java ...

* 3′ terminal

stem-loop Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when ...

s * canonical

Sm protein In molecular biology, LSm proteins are a family of RNA-binding proteins found in virtually every cellular organism. LSm is a contraction of 'like Sm', because the first identified members of the LSm protein family were the Sm proteins. LSm pro ...

-binding site (AUUUUUG) A proposed role for HSURs is that they use the

RNA interference RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded RNA, through translational or transcriptional repression. Historically, RNAi was known by o ...

(RNAi) pathway to manipulate host-cell gene expression. One identified

miRNA MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRN ...

which responds to HSURs is

miR-27 miR-27 is a family of microRNA precursors found in animals, including humans. MicroRNAs are typically transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. The excised region or ...

See also

References

Further reading