Protein SSX4 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, respo ...

that in humans is encoded by the ''SSX4''

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 ba ...

. The product of this gene belongs to the family of highly homologous synovial sarcoma, X (SSX) breakpoint proteins. These proteins may function as transcriptional

repressor In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the ...

s. They are also capable of eliciting spontaneously

humoral Humoral immunity is the aspect of immunity that is mediated by macromolecules - including secreted antibodies, complement proteins, and certain antimicrobial peptides - located in extracellular fluids. Humoral immunity is named so because it invo ...

and cellular immune responses in cancer patients, and are potentially useful targets in cancer vaccine-based immunotherapy. SSX1, SSX2 and SSX4 genes have been involved in the t(X;18)

chromosomal translocation In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes balanced and unbalanced translocation, with two main types: reciprocal-, and Robertsonian translocation. Reciprocal translo ...

characteristically found in all

synovial sarcoma A synovial sarcoma (also known as malignant synovioma) is a rare form of cancer which occurs primarily in the extremities of the arms or legs, often in proximity to joint capsules and tendon sheaths. It is a type of soft-tissue sarcoma. The name " ...

s. This translocation results in the fusion of the synovial sarcoma translocation gene on

chromosome 18 Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 80 million base pairs (the building material of DNA) and represents about 2.5 percent of the total DNA in ...

to one of the SSX genes on

chromosome X The X chromosome is one of the two sex-determining chromosomes (allosomes) in many organisms, including mammals (the other is the Y chromosome), and is found in both males and females. It is a part of the XY sex-determination system and XO sex-d ...

. Chromosome Xp11 contains a

segmental duplication Low copy repeats (LCRs), also known as segmental duplications (SDs), are highly homologous sequence elements within the eukaryotic genome. Repeats The repeats, or duplications, are typically 10–300 kb in length, and bear greater than 95% sequ ...

resulting in two identical copies of synovial sarcoma, X breakpoint 4, SSX4 and SSX4B, in tail-to-tail orientation. This gene, SSX4, represents the more

telomeric A telomere (; ) is a region of repetitive nucleotide sequences associated with specialized proteins at the ends of linear chromosomes. Although there are different architectures, telomeres, in a broad sense, are a widespread genetic feature mos ...

copy. Two

transcript variants Alternative splicing, or alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to code for multiple proteins. In this process, particular exons of a gene may be in ...

encoding distinct

isoform A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isof ...

s have been identified for this gene.

References

Further reading