RoXaN (Rotavirus 'X'-associated non-structural protein) also known as ZC3H7B (zinc finger CCCH-type containing 7B), is a

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, respon ...

that in humans is encoded by the ''ZC3H7B''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. RoXaN is a protein that contains tetratricopeptide repeat and leucine-aspartate repeat as well as

zinc finger A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn2+) in order to stabilize the fold. It was originally coined to describe the finger-like appearance of a hypothesized struct ...

domains. This protein also interacts with the

rotavirus ''Rotavirus'' is a genus of double-stranded RNA viruses in the family ''Reoviridae''. Rotaviruses are the most common cause of diarrhoeal disease among infants and young children. Nearly every child in the world is infected with a rotaviru ...

non-structural protein NSP3.

Function

Rotavirus ''Rotavirus'' is a genus of double-stranded RNA viruses in the family ''Reoviridae''. Rotaviruses are the most common cause of diarrhoeal disease among infants and young children. Nearly every child in the world is infected with a rotaviru ...

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 synthesizing a protein. mRNA is created during the ...

s are

capped In sport, a cap is a player's appearance in a game at international level. The term dates from the practice in the United Kingdom of awarding a cap to every player in an international match of rugby football and association football. In the ea ...

but not

polyadenylated Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In euka ...

, and viral proteins are

translated Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a terminological distinction (which does not exist in every language) between ''transla ...

by the cellular translation machinery. This is accomplished through the action of the viral

Nonstructural Protein In virology, a nonstructural protein is a protein encoded by a virus but that is not part of the viral particle. They typically include the various enzymes and transcription factors the virus uses to replicate itself, such as a viral protease ( 3CL ...

NSP3 which specifically binds the 3' consensus sequence of viral mRNAs and interacts with the eukaryotic translation initiation factor

eIF4G Eukaryotic translation initiation factor 4 G (eIF4G) is a protein involved in eukaryotic translation initiation and is a component of the eIF4F cap-binding complex. Orthologs of eIF4G have been studied in multiple species, including humans, yeast ...

I. RoXaN (rotavirus X protein associated with NSP3) is 110-kDa cellular protein that contains a minimum of three regions predicted to be involved in protein–protein or nucleic acid–protein interactions. A

tetratricopeptide The tetratricopeptide repeat (TPR) is a structural motif. It consists of a degenerate 34 amino acid tandem repeat identified in a wide variety of proteins. It is found in tandem arrays of 3–16 motifs, which form scaffolds to mediate protein–p ...

repeat region, a protein–protein interaction domain most often found in multiprotein complexes, is present in the amino-terminal region. In the carboxy terminus, at least five

motifs are observed, further suggesting the capacity of RoXaN to bind other proteins or nucleic acids. Between these two regions exists a

paxillin Paxillin is a protein that in humans is encoded by the ''PXN'' gene. Paxillin is expressed at focal adhesions of non-striated cells and at costameres of striated muscle cells, and it functions to adhere cells to the extracellular matrix. Mutation ...

leucine-aspartate repeat (LD) motif which is involved in protein–protein interactions.

Clinical significance

RoXaN is capable of interacting with NSP3 in vivo and during rotavirus infection. Domains of interaction correspond to the dimerization domain of NSP3 (amino acids 163 to 237) and the LD domain of RoXaN (amino acids 244 to 341). The interaction between NSP3 and RoXaN does not impair the interaction between NSP3 and eIF4G I, and a ternary complex made of NSP3, RoXaN, and eIF4G I can be detected in rotavirus-infected cells, implicating RoXaN in

translation Translation is the communication of the Meaning (linguistic), meaning of a #Source and target languages, source-language text by means of an Dynamic and formal equivalence, equivalent #Source and target languages, target-language text. The ...

regulation. Expression of RoXaN was found to be correlated with a higher tumor grad in GIST (

gastrointestinal stromal tumor Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajal, or similar cells. They are defined as tumors whose behavio ...

s).

Function

Clinical significance

References

Further reading