Stanniocalcin-1 is a

glycoprotein Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known a ...

, a homologue of a hormone stanniocalcin, first discovered in bony fishes. In humans it is encoded by the ''STC1''

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 ...

Function

This gene encodes a secreted,

homodimer In biochemistry, a protein dimer is a macromolecular complex or protein multimer, multimer formed by two protein monomers, or single proteins, which are usually Non-covalent interaction, non-covalently bound. Many macromolecules, such as proteins ...

that is expressed in a wide variety of tissues and may have

autocrine Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger (called the autocrine agent) that binds to autocrine receptors on that same cell, leading to changes in the cell. This can be contrasted with ...

paracrine In cellular biology, paracrine signaling is a form of cell signaling, a type of cellular communication (biology), cellular communication in which a Cell (biology), cell produces a signal to induce changes in nearby cells, altering the behaviour of ...

functions. The only known molecular function of human Stanniocalcin-1 to date is a

SUMO is a form of competitive full-contact wrestling where a ''rikishi'' (wrestler) attempts to force his opponent out of a circular ring (''dohyō'') or into touching the ground with any body part other than the soles of his feet (usually by th ...

E3 ubiquitin ligase A ubiquitin ligase (also called an E3 ubiquitin ligase) is a protein that recruits an E2 ubiquitin-conjugating enzyme that has been loaded with ubiquitin, recognizes a protein substrate, and assists or directly catalyzes the transfer of ubiquitin ...

activity in the SUMOylation cycle. However, STC1 interacts with many proteins in the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

mitochondria A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is us ...

, endoplasmatic reticulum, and in dot-like fashion in the

cell nucleus The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, ...

. The N-terminal region of STC1 is the function region which is responsible to establish the interaction with its partners, including SUMO1. Low-resolution studies shows that STC1 is an anti-parallel homodimer in solution and the cysteine 202 is responsible for its dimerization. All the 5

disulfide bond In chemistry, a disulfide (or disulphide in British English) is a compound containing a functional group or the anion. The linkage is also called an SS-bond or sometimes a disulfide bridge and usually derived from two thiol groups. In inor ...

s of human STC1 are conserved and have the same profile of fish STC. The gene contains a 5' UTR rich in CAG trinucleotide repeats. The encoded protein contains 11 conserved

cysteine Cysteine (; symbol Cys or C) is a semiessential proteinogenic amino acid with the chemical formula, formula . The thiol side chain in cysteine enables the formation of Disulfide, disulfide bonds, and often participates in enzymatic reactions as ...

residues and is phosphorylated by

protein kinase C In cell biology, protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and t ...

exclusively on its serine residues. The protein may play a role in the regulation of renal and intestinal calcium and phosphate transport, cell metabolism, or cellular calcium/phosphate

homeostasis In biology, homeostasis (British English, British also homoeostasis; ) is the state of steady internal physics, physical and chemistry, chemical conditions maintained by organism, living systems. This is the condition of optimal functioning fo ...

. Overexpression of human stanniocalcin 1 in mice produces high serum phosphate levels,

dwarfism Dwarfism is a condition of people and animals marked by unusually small size or short stature. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dwarfism is . '' ...

, and increased metabolic rate. This gene has altered expression in hepatocellular, ovarian, and breast cancers, and is a putative molecular biomarker of leukemic microenvironment.

Function

References

Further reading