Sorting nexin-21 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''SNX21''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. This gene encodes a member of the

sorting nexin Sorting nexins are a large group of proteins that are localized in the cytoplasm and have the potential for membrane association either through their lipid-binding PX domain (a phospholipid-binding Structural motif, motif) or through protein� ...

family. Members of this family contain a

phox In automated theorem proving, PhoX is a proof assistant based on higher-order logic which is eXtensible. The user gives PhoX an initial goal and guides it through subgoals and evidence to prove that goal; internally, it constructs natural deduction ...

(PX) domain, which is a

phosphoinositide Phosphatidylinositol or inositol phospholipid is a biomolecule. It was initially called "inosite" when it was discovered by Léon Maquenne and Johann Joseph von Scherer in the late 19th century. It was discovered in bacteria but later also found ...

binding domain, and are involved in intracellular trafficking. This protein does not contain a

coiled coil A coiled coil is a structural motif in proteins in which two to seven alpha-helices are coiled together like the strands of a rope. ( Dimers and trimers are the most common types.) They have been found in roughly 5-10% of proteins and have a ...

region, like some family members. The specific function of this protein has not been determined. Multiple

transcript variants Alternative splicing, alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to produce different splice variants. For example, some exons of a gene may be included ...

encoding distinct

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

have been identified for this gene.

References

Further reading