Basic salivary proline-rich protein 4 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 ''PRB4''

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 ...

. The protein encoded by this gene is a proline-rich

salivary protein Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be e ...

. This gene and five other genes that also encode salivary

proline-rich proteins Proline-rich proteins (PRPs) is a class of intrinsically unstructured proteins (IUP) containing several repeats of a short proline-rich sequence. Many tannin-consuming animals secrete a tannin-binding protein (mucin) in their saliva. Tannin-bindin ...

(PRPs), as well as a gene encoding a

lacrimal gland The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each o ...

PRP, form a PRP

gene cluster A gene family is a set of homologous genes within one organism. A gene cluster is a group of two or more genes found within an organism's DNA that encode similar polypeptides, or proteins, which collectively share a generalized function and are o ...

in the chromosomal 12p13 region. PRB4 is post-translationally cleaved into three different mature

peptides Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. ...

: *Protein N1 *Glycosylated protein A *Peptide P-D (also known as proline-rich peptide IB-5)

References

Further reading